WorldWideScience

Sample records for hot water heater

  1. Solar Hot Water Heater

    Science.gov (United States)

    1978-01-01

    The solar panels pictured below, mounted on a Moscow, Idaho home, are part of a domestic hot water heating system capable of providing up to 100 percent of home or small business hot water needs. Produced by Lennox Industries Inc., Marshalltown, Iowa, the panels are commercial versions of a collector co-developed by NASA. In an effort to conserve energy, NASA has installed solar collectors at a number of its own facilities and is conducting research to develop the most efficient systems. Lewis Research Center teamed with Honeywell Inc., Minneapolis, Minnesota to develop the flat plate collector shown. Key to the collector's efficiency is black chrome coating on the plate developed for use on spacecraft solar cells, the coating prevents sun heat from "reradiating," or escaping outward. The design proved the most effective heat absorber among 23 different types of collectors evaluated in a Lewis test program. The Lennox solar domestic hot water heating system has three main components: the array of collectors, a "solar module" (blue unit pictured) and a conventional water heater. A fluid-ethylene glycol and water-is circulated through the collectors to absorb solar heat. The fluid is then piped to a double-walled jacket around a water tank within the solar module.

  2. 10 CFR 431.102 - Definitions concerning commercial water heaters, hot water supply boilers, and unfired hot water...

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 3 2010-01-01 2010-01-01 false Definitions concerning commercial water heaters, hot water supply boilers, and unfired hot water storage tanks. 431.102 Section 431.102 Energy DEPARTMENT OF ENERGY... Water Heaters, Hot Water Supply Boilers and Unfired Hot Water Storage Tanks § 431.102 Definitions...

  3. Our Environment in Hot Water: Comparing Water Heaters, A Life Cycle Approach Comparing Tank and Tankless Water Heaters in California

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Alison; McMahon, James; Masanet, Eric; Lutz, Jim

    2008-08-13

    Residential water heating is a large source of energy use in California homes. This project took a life cycle approach to comparing tank and tankless water heaters in Northern and Southern California. Information about the life cycle phases was calculated using the European Union's Methodology study for EcoDesign of Energy-using Products (MEEUP) and the National Renewable Energy Laboratory's Life Cycle Inventory (NREL LCI) database. In a unit-to-unit comparison, it was found that tankless water heaters would lessen impacts of water heating by reducing annual energy use by 2800 MJ/year (16% compared to tank), and reducing global warming emissions by 175 kg CO2 eqv./year (18% reduction). Overall, the production and combustion of natural gas in the use phase had the largest impact. Total waste, VOCs, PAHs, particulate matter, and heavy-metals-to-air categories were also affected relatively strongly by manufacturing processes. It was estimated that tankless water heater users would have to use 10 more gallons of hot water a day (an increased usage of approximately 20%) to have the same impact as tank water heaters. The project results suggest that if a higher percentage of Californians used tankless water heaters, environmental impacts caused by water heating would be smaller.

  4. Solar hot water systems for the southeastern United States: principles and construction of breadbox water heaters

    Energy Technology Data Exchange (ETDEWEB)

    None

    1983-02-01

    The use of solar energy to provide hot water is among the easier solar technologies for homeowners to utilize. In the Southeastern United States, because of the mild climate and abundant sunshine, solar energy can be harnessed to provide a household's hot water needs during the non-freezing weather period mid-April and mid-October. This workbook contains detailed plans for building breadbox solar water heaters that can provide up to 65% of your hot water needs during warm weather. If fuel costs continue to rise, the annual savings obtained from a solar water heater will grow dramatically. The designs in this workbook use readily available materials and the construction costs are low. Although these designs may not be as efficient as some commercially available systems, most of a household's hot water needs can be met with them. The description of the breadbox water heater and other types of solar systems will help you make an informed decision between constructing a solar water heater or purchasing one. This workbook is intended for use in the southeastern United States and the designs may not be suitable for use in colder climates.

  5. Realistic Hot Water Draw Specification for Rating Solar Water Heaters: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Burch, J.

    2012-06-01

    In the United States, annual performance ratings for solar water heaters are simulated, using TMY weather and specified water draw. A more-realistic ratings draw is proposed that eliminates most bias by improving mains inlet temperature and by specifying realistic hot water use. This paper outlines the current and the proposed draws and estimates typical ratings changes from draw specification changes for typical systems in four cities.

  6. Summer Indoor Heat Pump Water Heater Evaluation in a Hot-Dry Climate

    Energy Technology Data Exchange (ETDEWEB)

    Hoeschele, Marc [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States); Seitzler, Matthew [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States)

    2017-05-01

    Heat pump water heaters offer a significant opportunity to improve water heating performance for the over 40% of U.S. households that heat domestic hot water using electric resistance storage water heaters. Numerous field studies have also been completed documenting performance in a variety of climates and applications. More recent evaluation efforts have focused attention on the performance of May through September 2014, with ongoing winter monitoring being sponsored by California utility partners. Summer results show favorable system performance with extrapolated annual water heating savings of 1,466 to 2,300 kWh per year, based on the observed hot water loads. Additional summer space cooling benefits savings of 121 to 135 kWh per year were projected, further increasing the water energy savings.

  7. 10 CFR 431.106 - Uniform test method for the measurement of energy efficiency of commercial water heaters and hot...

    Science.gov (United States)

    2010-01-01

    ... heaters). 431.106 Section 431.106 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY... of energy efficiency of commercial water heaters and hot water supply boilers (other than commercial...) Testing and Calculations. Determine the energy efficiency of each covered product by conducting the test...

  8. Building America Case Study: Indoor Heat Pump Water Heaters During Summer in a Hot-Dry Climate, Redding, California

    Energy Technology Data Exchange (ETDEWEB)

    M. Hoeschele, M. Seitzler

    2017-06-01

    Heat pump water heaters offer a significant opportunity to improve water heating performance for the over 40% of U.S. households that heat domestic hot water using electric resistance storage water heaters. Numerous field studies have also been completed documenting performance in a variety of climates and applications. More recent evaluation efforts have focused attention on the performance of May through September 2014, with ongoing winter monitoring being sponsored by California utility partners.

  9. To built a solar hot water heater to work the sustainability problem

    Directory of Open Access Journals (Sweden)

    Carretero Gómez, María Begoña

    2012-01-01

    Full Text Available We are commemorating the Education Decade for Sustainable Development. If we want to create positive towards our environment and its sustainable development we have to begin working at school. It is necessary to show our students what problems of the environment are and which solutions can be adopted. That is the reason we have planned this activity in our secondary school. We do think that by doing daily activities we have a good opportunity to fulfil this goal. An example of such experiences is the fabrication of a solar hot water heater to make them and their families more environment conscience.

  10. Retrofitting Domestic Hot Water Heaters for Solar Water Heating Systems in Single-Family Houses in a Cold Climate: A Theoretical Analysis

    OpenAIRE

    Björn Karlsson; Henrik Davidsson; Bernardo, Luis R.

    2012-01-01

    One of the biggest obstacles to economic profitability of solar water heating systems is the investment cost. Retrofitting existing domestic hot water heaters when a new solar hot water system is installed can reduce both the installation and material costs. In this study, retrofitting existing water heaters for solar water heating systems in Swedish single-family houses was theoretically investigated using the TRNSYS software. Four simulation models using forced circulation flow with differe...

  11. Performance of a Heat Pump Water Heater in the Hot-Humid Climate, Windermere, Florida (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)

    Metzger, C.; Puttagunta, S.; Williamson, J.

    2013-11-01

    Over recent years, heat pump water heaters (HPWHs) have become more readily available and more widely adopted in the marketplace. For a 6-month period, the Building America team Consortium for Advanced Residential Buildings monitored the performance of a GE Geospring HPWH in Windermere, Florida. The study found that the HPWH performed 144% more efficiently than a traditional electric resistance water heater, saving approximately 64% on water heating annually. The monitoring showed that the domestic hot water draw was a primary factor affecting the system's operating efficiency.

  12. Technology Solutions Case Study: Performance of a Heat Pump Water Heater in the Hot-Humid Climate, Windermere, Florida

    Energy Technology Data Exchange (ETDEWEB)

    None

    2013-11-01

    Over recent years, heat pump water heaters (HPWHs) have become more readily available and more widely adopted in the marketplace. For a 6-month period, the Building America team Consortium for Advanced Residential Buildings monitored the performance of a GE Geospring HPWH in Windermere, Florida. The study found that the HPWH performed 144% more efficiently than a traditional electric resistance water heater, saving approximately 64% on water heating annually. The monitoring showed that the domestic hot water draw was a primary factor affecting the system's operating efficiency.

  13. An experimental investigation with artificial sunlight of a solar hot-water heater

    Science.gov (United States)

    Simon, F. F.

    1976-01-01

    Thermal performance measurements were made of a commercial solar hot water heater in a solar simulator to determine basic performance characteristics of a traditional type of flat plate collector, with and without side reflectors (to increase the solar flux). Information on each of the following was obtained; (1) the effect of flow and incidence angle on the efficiency of a flat plate collector (but only without side reflectors); (2) transient performance under flow and nonflow conditions; (3) the effectiveness of reflectors to increase collector efficiency for a zero radiation angle at fluid temperatures required for solar air conditioning; and (4) the limits of applicability of a collector efficiency correlation based on the Hottel Whillier equation.

  14. Building America Case Study: Indoor Heat Pump Water Heaters During Summer in a Hot-Dry Climate, Redding, California

    Energy Technology Data Exchange (ETDEWEB)

    2017-06-15

    Heat pump water heaters offer a significant opportunity to improve water heating performance for the over 40% of U.S. households that heat domestic hot water using electric resistance storage water heaters. Numerous field studies have also been completed documenting performance in a variety of climates and applications. More recent evaluation efforts have focused attention on the performance of May through September 2014, with ongoing winter monitoring being sponsored by California utility partners. Summer results show favorable system performance with extrapolated annual water heating savings of 1,466 to 2,300 kWh per year, based on the observed hot water loads. Additional summer space cooling benefits savings of 121 to 135 kWh per year were projected, further increasing the water heating savings by 5-9%. Given the project schedule for 2014 completion, no heating season impacts were able to be monitored. May through September 2014, with ongoing winter monitoring being sponsored by California utility partners. Summer results show favorable system performance with extrapolated annual water heating savings of 1,466 to 2,300 kWh per year, based on the observed hot water loads. Additional summer space cooling benefits savings of 121 to 135 kWh per year were projected, further increasing the water heating savings by 5-9%. Given the project schedule for 2014 completion, no heating season impacts were able to be monitored.

  15. Compact instantaneous water heater

    Energy Technology Data Exchange (ETDEWEB)

    Azevedo, Jorge G.W.; Machado, Antonio R.; Ferraz, Andre D.; Rocha, Ivan C.C. da; Konishi, Ricardo [Companhia de Gas de Santa Catarina (SCGAS), Florianopolis, SC (Brazil); Lehmkuhl, Willian A.; Francisco Jr, Roberto W.; Hatanaka, Ricardo L.; Pereira, Fernando M.; Oliveira, Amir A.M. [Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil)

    2012-07-01

    This paper presents an experimental study of combustion in an inert porous medium in a liquid heating device application. This project aims to increase efficiency in the application of natural gas in residential and commercial sectors with the use of advanced combustion and heat transfer. The goal is to facilitate the development of a high performance compact water heater allowing hot water supply for up to two simultaneous showers. The experiment consists in a cylindrical porous burner with an integrated annular water heat exchanger. The reactants were injected radially into the burner and the flame stabilizes within the porous matrix. The water circulates in a coiled pipe positioned at the center of the burner. This configuration allows for heat transfer by conduction and radiation from the solid matrix to the heat exchanger. This article presented preliminary experimental results of a new water heater based on an annular porous burner. The range of equivalence ratios tested varied from 0.65 to 0.8. The power range was varied from 3 to 5 kW. Increasing the equivalence ratio or decreasing the total power input of the burner resulted in increased thermal efficiencies of the water heater. Thermal efficiencies varying from 60 to 92% were obtained. The condition for the goal of a comfortable bath was 20 deg C for 8-12 L/min. This preliminary prototype has achieved water temperature of 11deg C for 5 L/min. Further optimizations will be necessary in order to achieve intense heating with high thermal efficiency. (author)

  16. European Regional Climate Zone Modeling of a Commercial Absorption Heat Pump Hot Water Heater

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Vishaldeep [ORNL; Shen, Bo [ORNL; Keinath, Chris [Stone Mountain Technologies, Inc., Johnson City; Garrabrant, Michael A. [Stone Mountain Technologies, Inc., Johnson City; Geoghegan, Patrick J [ORNL

    2017-01-01

    High efficiency gas-burning hot water heating takes advantage of a condensing heat exchanger to deliver improved combustion efficiency over a standard non-condensing configuration. The water heating is always lower than the gas heating value. In contrast, Gas Absorption Heat Pump (GAHP) hot water heating combines the efficiency of gas burning with the performance increase from a heat pump to offer significant gas energy savings. An ammonia-water system also has the advantage of zero Ozone Depletion Potential and low Global Warming Potential. In comparison with air source electric heat pumps, the absorption system can maintain higher coefficients of performance in colder climates. In this work, a GAHP commercial water heating system was compared to a condensing gas storage system for a range of locations and climate zones across Europe. The thermodynamic performance map of a single effect ammonia-water absorption system was used in a building energy modeling software that could also incorporate the changing ambient air temperature and water mains temperature for a specific location, as well as a full-service restaurant water draw pattern.

  17. Extremophiles in Household Water Heaters

    Science.gov (United States)

    Wilpiszeski, R.; House, C. H.

    2016-12-01

    A significant fraction of Earth's microbial diversity comes from species living in extreme environments, but natural extreme environments can be difficult to access. Manmade systems like household water heaters serve as an effective proxy for thermophilic environments that are otherwise difficult to sample directly. As such, we are investigating the biogeography, taxonomic distribution, and evolution of thermophiles growing in domestic water heaters. Citizen scientists collected hot tap water culture- and filter- samples from 101 homes across the United States. We recovered a single species of thermophilic heterotroph from culture samples inoculated from water heaters across the United States, Thermus scotoductus. Whole-genome sequencing was conducted to better understand the distribution and evolution of this single species. We have also sequenced hyper-variable regions of the 16S rRNA gene from whole-community filter samples to identify the broad diversity and distribution of microbial cells captured from each water heater. These results shed light on the processes that shape thermophilic populations and genomes at a spatial resolution that is difficult to access in naturally occurring extreme ecosystems.

  18. Retrofitting Domestic Hot Water Heaters for Solar Water Heating Systems in Single-Family Houses in a Cold Climate: A Theoretical Analysis

    Directory of Open Access Journals (Sweden)

    Björn Karlsson

    2012-10-01

    Full Text Available One of the biggest obstacles to economic profitability of solar water heating systems is the investment cost. Retrofitting existing domestic hot water heaters when a new solar hot water system is installed can reduce both the installation and material costs. In this study, retrofitting existing water heaters for solar water heating systems in Swedish single-family houses was theoretically investigated using the TRNSYS software. Four simulation models using forced circulation flow with different system configurations and control strategies were simulated and analysed in the study. A comparison with a standard solar thermal system was also presented based on the annual solar fraction. The simulation results indicate that the retrofitting configuration achieving the highest annual performance consists of a system where the existing tank is used as storage for the solar heat and a smaller tank with a heater is added in series to make sure that the required outlet temperature can be met. An external heat exchanger is used between the collector circuit and the existing tank. For this retrofitted system an annual solar fraction of 50.5% was achieved. A conventional solar thermal system using a standard solar tank achieves a comparable performance for the same total storage volume, collector area and reference conditions.

  19. Performance and economic evaluation of the seahorse natural gas hot water heater conversion at Fort Stewart. Interim report, 1994 Summer

    Energy Technology Data Exchange (ETDEWEB)

    Winiarski, D.W.

    1995-01-01

    The federal government is the largest single energy consumer in the United States cost valued at nearly $10 billion annually. The US Department of Energy`s (DOE) Federal Energy Management Program (FEMP) supports efforts to reduce energy use and associated expenses in the federal sector. One such effort, the New Technology Demonstration Program (NTDP), seeks to evaluate new energy-saving US technologies and secure their more timely adoption by the US government. Pacific Northwest Laboratory (PNL) is one of four DOE laboratories that participate in the New Technologies Demonstration Program, providing technical expertise and equipment to evaluate new, energy-saving technologies being studied under that program. This interim report provides the results of a field evaluation that PNL conducted for DOE/FEMP and the US Department of Defense (DoD) Strategic Environmental Research and Development Program (SERDP) to examine the performance of a candidate energy-saving technology-a hot water heater conversion system to convert electrically heated hot water tanks to natural gas fuel. The unit was installed at a single residence at Fort Stewart, a US Army base in Georgia, and the performance was monitored under the NTDP. Participating in this effort under a Cooperative Research and Development Agreement (CRADA) were Gas Fired Products, developers of the technology; the Public Service Company of North Carolina; Atlanta Gas Light Company; the Army Corps of Engineers; Fort Stewart; and Pacific Northwest Laboratory.

  20. ENERGY STAR Certified Water Heaters

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 3.0 and Version 3.1 ENERGY STAR Program Requirements for Water Heaters that are effective...

  1. ENERGY STAR Certified Water Heaters

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 3.2 ENERGY STAR Program Requirements for Water Heaters that are effective April 16, 2015....

  2. Performance and economic evaluation of the seahorse natural gas hot water heater conversion at Fort Stewart. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Winiarski, D.W.

    1995-12-01

    The Federal government is the largest single energy consumer in the United States with consumption of nearly 1.5 quads/year of energy (10{sup 15} quad = 1015 Btu) and cost valued at nearly $10 billion annually. The US Department of Energy`s (DOE) Federal Energy Management Program (FEMP) supports efforts to reduce energy use and associated expenses in the Federal sector. One such effort, the New Technology Demonstration Program (NTDP) seeks to evaluate new energy -- saving US technologies and secure their more timely adoption by the US government. Pacific Northwest Laboratory (PNL) is one of four DOE laboratories that participate in the New Technologies Demonstration Program, providing technical expertise and equipment to evaluate new, energy-saving technologies being studied under that program. This report provides the results of a field evaluation that PNL conducted for DOE/FEMP with funding support from the US Department of Defense (DoD) Strategic Environmental Research and Development Program (SERDP) to examine the performance of 4 candidate energy-saving technology-a water heater conversion system to convert electrically powered water heaters to natural gas fuel. The unit was installed at a single residence at Fort Stewart, a US Army base in Georgia, and the performance was monitored under the NTDP. Participating in this effort under a Cooperative Research and Development Agreement (CRADA) were Gas Fired Products, developers of the technology; the Public Service Company of North Carolina; Atlanta Gas Light Company; the Army Corps of Engineers; Fort Stewart; and Pacific Northwest Laboratory.

  3. Experimental evaluation on the use of capillary tube and thermostatic expansion valve with heat recovery hot spot water heater in air source refrigeration system

    Science.gov (United States)

    Aziz, Azridjal; Mainil, Rahmat Iman; Mainil, Afdhal Kurniawan; Saputra, Eko

    2017-01-01

    The present experimental evaluation has been carried out to investigate the use of capillary tube (CT) and thermostatic expansion valve (TEV) with heat recovery hot spot water heater (HRHSWH) in air source compression refrigeration system. CT and TEV are the two basic types of refrigerant expansion devices that most frequently used in compression refrigeration system, but the identified about HRHSWH in extant literature are limited. The HRHSWH is modified from residential refrigeration system. The heat exchanger coil as HRHSWH was bonded with the compressor discharge pipe line as counter-flow heat exchanger, then insulated and placed them into transparent acrylic box. Water from storage tank with 50L capacity is pumped using circulation pump to the HRHSWH and heating the water in storage tank. The system performance of those two expansion devices in compression refrigeration system are evaluated and compared between with or without modified using HRHSWH. Results show that refrigeration system using TEV performs better performance than CT using HRHSWH compared to standard refrigeration system (without HRHSWH). The use of TEV device in HRHSWH causes a slight decrease in compressor power 0.0198 kW (4%), where the COP increases around 20% higher than the CT device. The finding indicates that the use of HRHSWH generates free hot water for TEV and CT with temperature around 54.06°C and 55.78°C, respectively. In general, HRHSWH give better perfomance than standar refrigeration system.

  4. Regional Climate Zone Modeling of a Commercial Absorption Heat Pump Hot Water Heater Part 1: Southern and South Central Climate Zones

    Energy Technology Data Exchange (ETDEWEB)

    Geoghegan, Patrick J [ORNL; Shen, Bo [ORNL; Keinath, Christopher M. [Stone Mountain Technologies, Inc., Johnson City; Garrabrant, Michael A. [Stone Mountain Technologies, Inc., Johnson City

    2016-01-01

    Commercial hot water heating accounts for approximately 0.78 Quads of primary energy use with 0.44 Quads of this amount from natural gas fired heaters. An ammonia-water based commercial absorption system, if fully deployed, could achieve a high level of savings, much higher than would be possible by conversion to the high efficiency nonheat-pump gas fired alternatives. In comparison with air source electric heat pumps, the absorption system is able to maintain higher coefficients of performance in colder climates. The ammonia-water system also has the advantage of zero Ozone Depletion Potential and low Global Warming Potential. A thermodynamic model of a single effect ammonia-water absorption system for commercial space and water heating was developed, and its performance was investigated for a range of ambient and return water temperatures. This allowed for the development of a performance map which was then used in a building energy modeling software. Modeling of two commercial water heating systems was performed; one using an absorption heat pump and another using a condensing gas storage system. The energy and financial savings were investigated for a range of locations and climate zones in the southern and south central United States. A follow up paper will analyze northern and north/central regions. Results showed that the system using an absorption heat pump offers significant savings.

  5. Improving Heat Pump Water Heater Effeciency by Avoiding Electric Resistance Heater Use

    Energy Technology Data Exchange (ETDEWEB)

    Boudreaux, Philip R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Munk, Jeffrey D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Jackson, Roderick K. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Gehl, Anthony C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Parkison, April E. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Nutaro, James J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2014-09-01

    Heat pump water heaters (HPWHs) are a promising technology that can decrease the domestic hot water energy consumption over an electric resistance storage water heater by up to 50%. Heat pump water heaters are really two water heaters in one; they can heat water by using a heat pump or by using electric resistance elements. During large water draw events the HPWHs will use the resistance elements that decrease the overall efficiency of the units. ORNL proposed and tested an advanced control algorithm that anticipates the large water draw events and appropriately sets-up the temperature of the tank water using only the heat pump. With sufficient energy stored in the tank at the elevated temperature, the large water draw is provided for and electric resistance use is avoided. Simulations using a validated heat pump water heater model, and measured water draw data from 25 homes, show average yearly energy savings of 9% for the advanced control algorithm. If the advanced control algorithm perfectly predicts the large water draw events then the savings increase to 19%. This discrepancy could be due to a lack of predictability of water draw patterns in some homes, or the water draw forecasting algorithm could be improved.

  6. Heat Pump Water Heaters and American Homes: A Good Fit?

    Energy Technology Data Exchange (ETDEWEB)

    Franco, Victor; Lekov, Alex; Meyers, Steve; Letschert, Virginie

    2010-05-14

    Heat pump water heaters (HPWHs) are over twice as energy-efficient as conventional electric resistance water heaters, with the potential to save substantial amounts of electricity. Drawing on analysis conducted for the U.S. Department of Energy's recently-concluded rulemaking on amended standards for water heaters, this paper evaluates key issues that will determine how well, and to what extent, this technology will fit in American homes. The key issues include: 1) equipment cost of HPWHs; 2) cooling of the indoor environment by HPWHs; 3) size and air flow requirements of HPWHs; 4) performance of HPWH under different climate conditions and varying hot water use patterns; and 5) operating cost savings under different electricity prices and hot water use. The paper presents the results of a life-cycle cost analysis of the adoption of HPWHs in a representative sample of American homes, as well as national impact analysis for different market share scenarios. Assuming equipment costs that would result from high production volume, the results show that HPWHs can be cost effective in all regions for most single family homes, especially when the water heater is not installed in a conditioned space. HPWHs are not cost effective for most manufactured home and multi-family installations, due to lower average hot water use and the water heater in the majority of cases being installed in conditioned space, where cooling of the indoor environment and size and air flow requirements of HPWHs increase installation costs.

  7. Integral-type solar water heater using loop heat pipe

    Energy Technology Data Exchange (ETDEWEB)

    Huang, B.J.; Yang, P.E.; Wang, J.H.; Wu, J.H. [New Energy Center, Taiwan Univ., Taipei (China)

    2008-07-01

    Taiwan University has been devoted to the development of low-cost LHP (loop hat pipe). A new manufacturing process for low-cost LHP has been developed that leads to a cost down to less than 10 USD for a 100W LHP. The present study utilizes the low-cost LHP to develop a new type of solar water heater. A thermosyphon which is thermally bonded with a solar absorber plate is used to absorb solar energy and transfer the heat upward to the evaporator of the LHP. From that, the heat is conducted downward to the condenser of the LHP which is immersed in a hot water tank beneath the solar collector. The solar water heater thus can be designed in integral type with streamline shape which is easy to install and has a good outlook as well as high efficiency. A prototype was designed and fabricated in the present study. A preliminary heat transfer test for a single unit of thermosyphon-LHP combination shows that it is capable of transferring the absorbed energy downward to the LHP condenser immersed in a hot water tank. The overall thermal resistance from the absorber plate to water is 0.34 C/W. and the thermal resistance of the LHP is 0.16 C/W. Two prototypes of the solar water heaters with 50 liters and 80 liters hot water tanks were designed according to the results of the feasibility test. In addition, an automatic monitoring system was designed and set up for the performance test of these two solar water heaters based on the test standard CNS B7277. The measured overall thermal resistance from solar absorber plate to water is 0.369 C/W. The daily solar water heater efficiency is 0.503. The present study has shown that the application of low-cost LHP in solar water heater is feasible and cost competitive. (orig.)

  8. Strategy Guideline. Proper Water Heater Selection

    Energy Technology Data Exchange (ETDEWEB)

    Hoeschele, M. [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States); Springer, D. [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States); German, A. [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States); Staller, J. [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States); Zhang, Y. [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States)

    2015-04-09

    This Strategy Guideline on proper water heater selection was developed by the Building America team Alliance for Residential Building Innovation to provide step-by-step procedures for evaluating preferred cost-effective options for energy efficient water heater alternatives based on local utility rates, climate, and anticipated loads.

  9. Strategy Guideline: Proper Water Heater Selection

    Energy Technology Data Exchange (ETDEWEB)

    Hoeschele, M. [Alliance for Residential Building Innovation, Davis, CA (United States); Springer, D. [Alliance for Residential Building Innovation, Davis, CA (United States); German, A. [Alliance for Residential Building Innovation, Davis, CA (United States); Staller, J. [Alliance for Residential Building Innovation, Davis, CA (United States); Zhang, Y. [Alliance for Residential Building Innovation, Davis, CA (United States)

    2015-04-01

    This Strategy Guideline on proper water heater selection was developed by the Building America team Alliance for Residential Building Innovation to provide step-by-step procedures for evaluating preferred cost-effective options for energy efficient water heater alternatives based on local utility rates, climate, and anticipated loads.

  10. Engineering solutions for polymer composites solar water heaters production

    Science.gov (United States)

    Frid, S. E.; Arsatov, A. V.; Oshchepkov, M. Yu.

    2016-06-01

    Analysis of engineering solutions aimed at a considerable decrease of solar water heaters cost via the use of polymer composites in heaters construction and solar collector and heat storage integration into a single device representing an integrated unit results are considered. Possibilities of creating solar water heaters of only three components and changing welding, soldering, mechanical treatment, and assembly of a complicate construction for large components molding of polymer composites and their gluing are demonstrated. Materials of unit components and engineering solutions for their manufacturing are analyzed with consideration for construction requirements of solar water heaters. Optimal materials are fiber glass and carbon-filled plastics based on hot-cure thermosets, and an optimal molding technology is hot molding. It is necessary to manufacture the absorbing panel as corrugated and to use a special paint as its selective coating. Parameters of the unit have been optimized by calculation. Developed two-dimensional numerical model of the unit demonstrates good agreement with the experiment. Optimal ratio of daily load to receiving surface area of a solar water heater operating on a clear summer day in the midland of Russia is 130‒150 L/m2. Storage tank volume and load schedule have a slight effect on solar water heater output. A thermal insulation layer of 35‒40 mm is sufficient to provide an efficient thermal insulation of the back and side walls. An experimental model layout representing a solar water heater prototype of a prime cost of 70‒90/(m2 receiving surface) has been developed for a manufacturing volume of no less than 5000 pieces per year.

  11. Assessing the Energy Savings of Tankless Water Heater Retrofits in Public Housing

    Energy Technology Data Exchange (ETDEWEB)

    Ries, R. [Univ. of Florida, Gainesville, FL (United States). Building Energy Efficient Housing for America (BEEHA)Team; Walters, R. [Univ. of Florida, Gainesville, FL (United States). Building Energy Efficient Housing for America (BEEHA)Team; Dwiantoro, D. [Univ. of Florida, Gainesville, FL (United States). Building Energy Efficient Housing for America (BEEHA)Team

    2013-01-01

    This report describes the methodology, analysis, and findings from a case study of a 110 unit retrofit of gas tankless water heaters in a hot/humid climate in Alachua County, Florida.The gas-fired tank type water heaters in the housing units were replaced with gas-fired tankless water heaters as part of a federal program that targeted reduced energy use in public housing.

  12. Assessing the Energy Savings of Tankless Water Heater Retrofits in Public Housing

    Energy Technology Data Exchange (ETDEWEB)

    Ries, R.; Walters, R.; Dwiantoro, D.

    2013-01-01

    This report describes the methodology, analysis, and findings from a case study of a 110 unit retrofit of gas tankless water heaters in a hot/humid climate in Alachua County, Florida. The housing units had their gas-fired tank type water heaters replaced with gas-fired tankless water heaters as part of a federal program that targeted reduced energy use in public housing.

  13. Retrofitting Conventional Electric Domestic Hot Water Heaters to Solar Water Heating Systems in Single-Family Houses—Model Validation and Optimization

    OpenAIRE

    Bernardo, Luis R.

    2013-01-01

    System cost reductions and development of standardised plug-and-function systems are some of the most important goals for solar heating technology development. Retrofitting hot water boilers in single-family houses when installing solar collectors has the potential to significantly reduce both material and installation costs. In this study, the TRNSYS simulation models of the retrofitting solar thermal system were validated against measurements. Results show that the validated models are in g...

  14. Assessment of a Hybrid Retrofit Gas Water Heater

    Energy Technology Data Exchange (ETDEWEB)

    Hoeschele, Marc [Davis Energy Group, Davis, CA (United States); Weitzel, Elizabeth [Davis Energy Group, Davis, CA (United States); Backman, Christine [Davis Energy Group, Davis, CA (United States)

    2017-02-28

    This project completed a modeling evaluation of a hybrid gas water heater that combines a reduced capacity tankless unit with a downsized storage tank. This product would meet a significant market need by providing a higher efficiency gas water heater solution for retrofit applications while maintaining compatibility with the 1/2 inch gas lines and standard B vents found in most homes. The TRNSYS simulation tool was used to model a base case 0.60 EF atmospheric gas storage water, a 0.82 EF non-condensing gas tankless water heater, an existing (high capacity) hybrid unit on the market, and an alternative hybrid unit with lower storage volume and reduced gas input requirements. Simulations were completed under a 'peak day' sizing scenario with 183 gpd hot water loads in a Minnesota winter climate case. Full-year simulations were then completed in three climates (ranging from Phoenix to Minneapolis) for three hot water load scenarios (36, 57, and 96 gpd). Model projections indicate that the alternative hybrid offers an average 4.5% efficiency improvement relative to the 0.60 EF gas storage unit across all scenarios modeled. The alternative hybrid water heater evaluated does show promise, but the current low cost of natural gas across much of the country and the relatively small incremental efficiency improvement poses challenges in initially building a market demand for the product.

  15. Assessment of a Hybrid Retrofit Gas Water Heater

    Energy Technology Data Exchange (ETDEWEB)

    Hoeschele, Marc [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States); Weitzel, Elizabeth [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States); Backman, Christine [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States)

    2017-02-01

    This project completed a modeling evaluation of a hybrid gas water heater that combines a reduced capacity tankless unit with a downsized storage tank. This product would meet a significant market need by providing a higher efficiency gas water heater solution for retrofit applications while maintaining compatibility with the 1/2 inch gas lines and standard B vents found in most homes. The TRNSYS simulation tool was used to model a base case 0.60 EF atmospheric gas storage water, a 0.82 EF non-condensing gas tankless water heater, an existing (high capacity) hybrid unit on the market, and an alternative hybrid unit with lower storage volume and reduced gas input requirements. Simulations were completed under a 'peak day' sizing scenario with 183 gpd hot water loads in a Minnesota winter climate case. Full-year simulations were then completed in three climates (ranging from Phoenix to Minneapolis) for three hot water load scenarios (36, 57, and 96 gpd). Model projections indicate that the alternative hybrid offers an average 4.5% efficiency improvement relative to the 0.60 EF gas storage unit across all scenarios modeled. The alternative hybrid water heater evaluated does show promise, but the current low cost of natural gas across much of the country and the relatively small incremental efficiency improvement poses challenges in initially building a market demand for the product.

  16. ENERGY STAR Certified Commercial Water Heaters

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 1.0 ENERGY STAR Program Requirements for Commercial Water Heaters that are effective as...

  17. Retrofitting Conventional Electric Domestic Hot Water Heaters to Solar Water Heating Systems in Single-Family Houses—Model Validation and Optimization

    Directory of Open Access Journals (Sweden)

    Luis R. Bernardo

    2013-02-01

    Full Text Available System cost reductions and development of standardised plug-and-function systems are some of the most important goals for solar heating technology development. Retrofitting hot water boilers in single-family houses when installing solar collectors has the potential to significantly reduce both material and installation costs. In this study, the TRNSYS simulation models of the retrofitting solar thermal system were validated against measurements. Results show that the validated models are in good agreement with measurements. On an annual basis a deviation of 2.5% out of 1099 kWh was obtained between the auxiliary energy from results and from the simulation model for a complete system. Using the validated model a system optimization was carried out with respect to control strategies for auxiliary heating, heat losses and volume of auxiliary storage. A sensitivity analysis was carried out regarding different volumes of retrofitted hot water boiler, DHW profiles and climates. It was estimated that, with adequate improvements, extended annual solar fractions of 60%, 78% and 81% can be achieved for Lund (Sweden, Lisbon (Portugal and Lusaka (Zambia, respectively. The correspondent collector area was 6, 4 and 3 m2, respectively. The studied retrofitted system achieves a comparable performance with conventional solar thermal systems with the potential to reduce the investment cost.

  18. Sanitary hot water; Eau chaude sanitaire

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-07-01

    Cegibat, the information-recommendation agency of Gaz de France for building engineering professionals, has organized this conference meeting on sanitary hot water to present the solutions proposed by Gaz de France to meet its clients requirements in terms of water quality, comfort, energy conservation and respect of the environment: quantitative aspects of the hot water needs, qualitative aspects, presentation of the Dolce Vita offer for residential buildings, gas water heaters and boilers, combined solar-thermal/natural gas solutions, key-specifications of hot water distribution systems, testimony: implementation of a gas hot water reservoir and two accumulation boilers in an apartment building for young workers. (J.S.)

  19. The sun as hot water source. Answers to questions on the solar water heater; Le soleil source d'eau chaude. Les reponses a vos questions sur le chauffe-eau solaire

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-07-01

    This guide answers to the main questions concerning a water heating system for domestic use. It aims to help the people who want to buy a solar water heater, to better estimate the advantages and the limits, in providing information on the operating and the use. (A.L.B.)

  20. Field Monitoring Protocol: Heat Pump Water Heaters

    Energy Technology Data Exchange (ETDEWEB)

    Sparn, B.; Earle, L.; Christensen, D.; Maguire, J.; Wilson, E.; Hancock, E.

    2013-02-01

    This document provides a standard field monitoring protocol for evaluating the installed performance of Heat Pump Water Heaters in residential buildings. The report is organized to be consistent with the chronology of field test planning and execution. Research questions are identified first, followed by a discussion of analysis methods, and then the details of measuring the required information are laid out. A field validation of the protocol at a house near the NREL campus is included for reference.

  1. Field Monitoring Protocol. Heat Pump Water Heaters

    Energy Technology Data Exchange (ETDEWEB)

    Sparn, B. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Earle, L. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Christensen, D. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Maguire, J. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Wilson, E. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Hancock, C. E. [Mountain Energy Partnership, Longmont, CO (United States)

    2013-02-01

    This document provides a standard field monitoring protocol for evaluating the installed performance of Heat Pump Water Heaters in residential buildings. The report is organized to be consistent with the chronology of field test planning and execution. Research questions are identified first, followed by a discussion of analysis methods, and then the details of measuring the required information are laid out. A field validation of the protocol at a house near the NREL campus is included for reference.

  2. Field Performance of Heat Pump Water Heaters in the Northeast

    Energy Technology Data Exchange (ETDEWEB)

    Shapiro, Carl [Consortium for Advanced Residential Buildings, Norwalk, CT (United States); Puttagunta, Srikanth [Consortium for Advanced Residential Buildings, Norwalk, CT (United States)

    2016-02-01

    Heat pump water heaters (HPWHs) are finally entering the mainstream residential water heater market. Potential catalysts are increased consumer demand for higher energy efficiency electric water heating and a new Federal water heating standard that effectively mandates use of HPWHs for electric storage water heaters with nominal capacities greater than 55 gallons. When compared to electric resistance water heating, the energy and cost savings potential of HPWHs is tremendous. Converting all electric resistance water heaters to HPWHs could save American consumers 7.8 billion dollars annually ($182 per household) in water heating operating costs and cut annual residential source energy consumption for water heating by 0.70 quads.

  3. A case study of electric utility demand reduction with commerical solar water heaters

    Energy Technology Data Exchange (ETDEWEB)

    Ewert, M.; Hoffner, J.E.; Panico, D. (City of Austin Electric Utility Dept., Austin, TX (US))

    1991-05-01

    The City of Austin, is studying the impact of solar water heaters on summer peak electric demand. One passive and two active solar water heating systems were installed on city owned commercial buildings which had electric water heaters in 1985 and have been monitored for two years. This paper reports on a method that has been developed to determine the peak demand reduction attributable to the solar systems. Results show that solar water heating systems are capable of large demand reductions as long as there is a large hot water demand to displace. The average noncoincident demand reduction (during the water heater's peak output) ranged from 0.8 to 5.8 kilowatts per system, however, the coincident demand reduction during the utility peak demand period was 0.3 to 0.8 kilowatts per system. Thus, a critical factor when assessing the benefit to the electric utility is the time of hot water demand.

  4. Solar Hot Water for Motor Inn--Texas City, Texas

    Science.gov (United States)

    1982-01-01

    Final report describes solar domestic-hot-water heater installation at LaQuinta Motor Inn, Texas City, Texas which furnished 63% of total hot-water load of new 98-unit inn. Report presents a description of system, drawings and photographs of collectors, operations and maintenance instructions, manufacturers' specifications for pumps, and an engineer's report on performance.

  5. Laboratory Evaluation of Gas-Fired Tankless and Storage Water Heater Approaches to Combination Water and Space Heating

    Energy Technology Data Exchange (ETDEWEB)

    Kingston, T. [Gas Technology Inst., Des Plaines, IL (United States); Scott, S. [Gas Technology Inst., Des Plaines, IL (United States)

    2013-03-01

    Homebuilders are exploring more cost-effective combined space and water heating systems (combo systems) with major water heater manufacturers that are offering pre-engineered forced air space heating combo systems. In this project, unlike standardized tests, laboratory tests were conducted that subjected condensing tankless and storage water heater based combo systems to realistic, coincidental space and domestic hot water loads and found that the tankless combo system maintained more stable DHW and space heating temperatures than the storage combo system, among other key findings.

  6. Building America Case Study: Assessment of a Hybrid Retrofit Gas Water Heater

    Energy Technology Data Exchange (ETDEWEB)

    2017-06-19

    This project completed a modeling evaluation of a hybrid gas water heater that combines a reduced capacity tankless unit with a downsized storage tank. This product would meet a significant market need by providing a higher efficiency gas water heater solution for retrofit applications while maintaining compatibility with the half-inch gas lines and standard B vents found in most homes. The TRNSYS simulation tool was used to model a base case 0.60 EF atmospheric gas storage water, a 0.82 EF non-condensing gas tankless water heater, an existing (high capacity) hybrid unit on the market, and an alternative hybrid unit with lower storage volume and reduced gas input requirements. Simulations were completed under a 'peak day' sizing scenario with 183 gpd hot water loads in a Minnesota winter climate case. Full-year simulations were then completed in three climates (ranging from Phoenix to Minneapolis) for three hot water load scenarios (36, 57, and 96 gpd). Model projections indicate that the alternative hybrid offers an average 4.5% efficiency improvement relative to the 0.60 EF gas storage unit across all scenarios modeled. The alternative hybrid water heater evaluated does show promise, but the current low cost of natural gas across much of the country and the relatively small incremental efficiency improvement poses challenges in initially building a market demand for the product.

  7. Multifamily Heat Pump Water Heater Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Hoeschele, M. [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States); Weitzel, E. [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States)

    2013-11-22

    Although heat pump water heaters (HPWHs) have gained significant attention in recent years as a high efficiency electric water heating solution for single family homes, central HPWHs for commercial or multi-family applications are not as well documented in terms of measured performance and cost effectiveness. To evaluate this technology, the Alliance for Residential Building Innovation team monitored the performance of a 10.5 ton central HPWH installed on a student apartment building at the West Village Zero Net Energy Community in Davis, California. Monitoring data collected over a 16 month period were then used to validate a TRNSYS simulation model. The TRNSYS model was then used to project performance in different climates using local electric rates. Results of the study indicate that after some initial commissioning issues, the HPWH operated reliably with an annual average efficiency of 2.12 (Coefficient of Performance). The observed efficiency was lower than the unit's rated efficiency, primarily due to the fact that the system rarely operated under steady-state conditions. Changes in the system configuration, storage tank sizing, and control settings would likely improve the observed field efficiency. Modeling results suggest significant energy savings relative to electric storage water heating systems (typical annual efficiencies around 0.90) providing for typical simple paybacks of six to ten years without any incentives. The economics versus gas water heating are currently much more challenging given the current low natural gas prices in much of the country. Increased market size for this technology would benefit cost effectiveness and spur greater technology innovation.

  8. Multifamily Heat Pump Water Heater Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Hoeschele, M. [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States); Weitzel, E. [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States)

    2017-03-01

    Although heat pump water heaters (HPWHs) have gained significant attention in recent years as a high efficiency electric water heating solution for single family homes, central HPWHs for commercial or multi-family applications are not as well documented in terms of measured performance and cost effectiveness. To evaluate this technology, the Alliance for Residential Building Innovation team monitored the performance of a 10.5 ton central HPWH installed on a student apartment building at the West Village Zero Net Energy Community in Davis, California. Monitoring data collected over a 16 month period were then used to validate a TRNSYS simulation model. The TRNSYS model was then used to project performance in different climates using local electric rates. Results of the study indicate that after some initial commissioning issues, the HPWH operated reliably with an annual average efficiency of 2.12 (Coefficient of Performance). The observed efficiency was lower than the unit's rated efficiency, primarily due to the fact that the system rarely operated under steady-state conditions. Changes in the system configuration, storage tank sizing, and control settings would likely improve the observed field efficiency. Modeling results suggest significant energy savings relative to electric storage water heating systems (typical annual efficiencies around 0.90) providing for typical simple paybacks of six to ten years without any incentives. The economics versus gas water heating are currently much more challenging given the current low natural gas prices in much of the country. Increased market size for this technology would benefit cost effectiveness and spur greater technology innovation.

  9. Multifamily Heat Pump Water Heater Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Hoeschele, M. [Davis Energy Group, Davis, CA (United States). Alliance for Residential Building Innovation; Weitzel, E. [Davis Energy Group, Davis, CA (United States). Alliance for Residential Building Innovation

    2017-03-03

    Although heat pump water heaters (HPWHs) have gained significant attention in recent years as a high efficiency electric water heating solution for single family homes, central HPWHs for commercial or multi-family applications are not as well documented in terms of measured performance and cost effectiveness. To evaluate this technology, the Alliance for Residential Building Innovation team monitored the performance of a 10.5 ton central HPWH installed on a student apartment building at the West Village Zero Net Energy Community in Davis, California. Monitoring data collected over a 16 month period were then used to validate a TRNSYS simulation model. The TRNSYS model was then used to project performance in different climates using local electric rates. Results of the study indicate that after some initial commissioning issues, the HPWH operated reliably with an annual average efficiency of 2.12 (Coefficient of Performance). The observed efficiency was lower than the unit's rated efficiency, primarily due to the fact that the system rarely operated under steady-state conditions. Changes in the system configuration, storage tank sizing, and control settings would likely improve the observed field efficiency. Modeling results suggest significant energy savings relative to electric storage water heating systems (typical annual efficiencies around 0.90) providing for typical simple paybacks of six to ten years without any incentives. The economics versus gas water heating are currently much more challenging given the current low natural gas prices in much of the country. Increased market size for this technology would benefit cost effectiveness and spur greater technology innovation.

  10. Heat pump water heater and storage tank assembly

    Science.gov (United States)

    Dieckmann, John T.; Nowicki, Brian J.; Teagan, W. Peter; Zogg, Robert

    1999-09-07

    A water heater and storage tank assembly comprises a housing defining a chamber, an inlet for admitting cold water to the chamber, and an outlet for permitting flow of hot water from the chamber. A compressor is mounted on the housing and is removed from the chamber. A condenser comprises a tube adapted to receive refrigerant from the compressor, and winding around the chamber to impart heat to water in the chamber. An evaporator is mounted on the housing and removed from the chamber, the evaporator being adapted to receive refrigerant from the condenser and to discharge refrigerant to conduits in communication with the compressor. An electric resistance element extends into the chamber, and a thermostat is disposed in the chamber and is operative to sense water temperature and to actuate the resistance element upon the water temperature dropping to a selected level. The assembly includes a first connection at an external end of the inlet, a second connection at an external end of the outlet, and a third connection for connecting the resistance element, compressor and evaporator to an electrical power source.

  11. Regional Variation in Residential Heat Pump Water Heater Performance in the U.S.

    Energy Technology Data Exchange (ETDEWEB)

    Maguire, Jeff [National Renewable Energy Lab. (NREL), Golden, CO (United States); Burch, Jay [National Renewable Energy Lab. (NREL), Golden, CO (United States); Merrigan, Tim [National Renewable Energy Lab. (NREL), Golden, CO (United States); Ong, Sean [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2014-01-01

    Residential heat pump water heaters (HPWHs) have recently re-emerged on the U.S. market, and they have the potential to provide homeowners significant cost and energy savings. However, actual in use performance of a HPWH will vary significantly with climate, installation location, HVAC equipment, and hot water use. To determine the actual energy consumption of a HPWH in different U.S. regions, annual simulations of both 50 and 80 gallon HPWHs as well as a standard electric water heater were performed for over 900 locations across the United States. The simulations included a benchmark home to take into account interactions between the space conditioning equipment and the HPWH and a realistic hot water draw profile. It was found that the HPWH will always save some source energy when compared to a standard electric resistance water heater, although savings varies widely with location. In addition to looking at source energy savings, the breakeven cost (the net installed cost a HPWH would have to have to be a cost neutral replacement for a standard water heater) was also examined. The highest breakeven costs were seen in cases with high energy savings, such as the southeastern U.S., or high energy costs, such as New England and California. While the breakeven cost is higher for 80 gallon units than 50 gallon units, the higher net installed costs of an 80 gallon unit lead to the 50 gallon HPWHs being more likely to be cost effective.

  12. Regional Variation in Residential Heat Pump Water Heater Performance in the U.S.: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Maguire, J.; Burch, J.; Merrigan, T.; Ong, S.

    2014-01-01

    Residential heat pump water heaters (HPWHs) have recently reemerged on the U.S. market. These units have the potential to provide homeowners significant cost and energy savings. However, actual in use performance of a HPWH will vary significantly with climate, installation location, HVAC equipment, and hot water use. To determine what actual in use energy consumption of a HPWH may be in different regions of the U.S., annual simulations of both 50 and 80 gallon HPWHs as well as a standard electric water heater were performed for over 900 locations across the U.S. The simulations included a benchmark home to take into account interactions between the space conditioning equipment and the HPWH and a realistic hot water draw profile. It was found that the HPWH will always save some source energy when compared to a standard electric resistance water heater, although savings varies widely with location. In addition to looking at source energy savings, the breakeven cost (the net installed cost a HPWH would have to have to be a cost neutral replacement for a standard water heater) was also examined. The highest breakeven costs were seen in cases with high energy savings, such as the southeastern U.S., or high energy costs, such as New England and California. While the breakeven cost is higher for 80 gallon units than 50 gallon units, the higher net installed costs of an 80 gallon unit lead to the 50 gallon HPWHs being more likely to be cost effective.

  13. 76 FR 63211 - Energy Efficiency Program: Test Procedures for Residential Water Heaters, Direct Heating...

    Science.gov (United States)

    2011-10-12

    ...-0042] RIN 1904-AC53 Energy Efficiency Program: Test Procedures for Residential Water Heaters, Direct... energy efficiency of electric instantaneous water heaters. c. Storage Water Heaters With Very Large... Approach to Predicting the Energy Efficiency of Residential Water Heaters-- Testing of Gas Tankless and...

  14. Disaggregating Hot Water Use and Predicting Hot Water Waste in Five Test Homes

    Energy Technology Data Exchange (ETDEWEB)

    Henderson, H.; Wade, J.

    2014-04-01

    While it is important to make the equipment (or 'plant') in a residential hot water system more efficient, the hot water distribution system also affects overall system performance and energy use. Energy wasted in heating water that is not used is estimated to be on the order of 10 to 30 percent of total domestic hot water (DHW) energy use. This field monitoring project installed temperature sensors on the distribution piping (on trunks and near fixtures) and programmed a data logger to collect data at 5 second intervals whenever there was a hot water draw. This data was used to assign hot water draws to specific end uses in the home as well as to determine the portion of each hot water that was deemed useful (i.e., above a temperature threshold at the fixture). Five houses near Syracuse NY were monitored. Overall, the procedures to assign water draws to each end use were able to successfully assign about 50% of the water draws, but these assigned draws accounted for about 95% of the total hot water use in each home. The amount of hot water deemed as useful ranged from low of 75% at one house to a high of 91% in another. At three of the houses, new water heaters and distribution improvements were implemented during the monitoring period and the impact of these improvements on hot water use and delivery efficiency were evaluated.

  15. Disaggregating Hot Water Use and Predicting Hot Water Waste in Five Test Homes

    Energy Technology Data Exchange (ETDEWEB)

    Henderson, Hugh [ARIES Collaborative, New York, NY (United States); Wade, Jeremy [ARIES Collaborative, New York, NY (United States)

    2014-04-01

    While it is important to make the equipment (or "plant") in a residential hot water system more efficient, the hot water distribution system also affects overall system performance and energy use. Energy wasted in heating water that is not used is estimated to be on the order of 10%-30% of total domestic hot water (DHW) energy use. This field monitoring project installed temperature sensors on the distribution piping (on trunks and near fixtures) in five houses near Syracuse, NY, and programmed a data logger to collect data at 5 second intervals whenever there was a hot water draw. This data was used to assign hot water draws to specific end uses in the home as well as to determine the portion of each hot water that was deemed useful (i.e., above a temperature threshold at the fixture). Overall, the procedures to assign water draws to each end use were able to successfully assign about 50% of the water draws, but these assigned draws accounted for about 95% of the total hot water use in each home. The amount of hot water deemed as useful ranged from low of 75% at one house to a high of 91% in another. At three of the houses, new water heaters and distribution improvements were implemented during the monitoring period and the impact of these improvements on hot water use and delivery efficiency were evaluated.

  16. Exergy analysis of integrated photovoltaic thermal solar water heater under constant flow rate and constant collection temperature modes

    NARCIS (Netherlands)

    Tiwari, A.; Dubey, Swapnil; Sandhu, G.S.; Sodha, M.S.; Anwar, S.I.

    2009-01-01

    In this communication, an analytical expression for the water temperature of an integrated photovoltaic thermal solar (IPVTS) water heater under constant flow rate hot water withdrawal has been obtained. Analysis is based on basic energy balance for hybrid flat plate collector and storage tank,

  17. An International Survey of Electric Storage Tank Water Heater Efficiency and Standards

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Alissa; Lutz, James; McNeil, Michael A.; Covary, Theo

    2013-11-13

    Water heating is a main consumer of energy in households, especially in temperate and cold climates. In South Africa, where hot water is typically provided by electric resistance storage tank water heaters (geysers), water heating energy consumption exceeds cooking, refrigeration, and lighting to be the most consumptive single electric appliance in the home. A recent analysis for the Department of Trade and Industry (DTI) performed by the authors estimated that standing losses from electric geysers contributed over 1,000 kWh to the annual electricity bill for South African households that used them. In order to reduce this burden, the South African government is currently pursuing a programme of Energy Efficiency Standards and Labelling (EES&L) for electric appliances, including geysers. In addition, Eskom has a history of promoting heat pump water heaters (HPWH) through incentive programs, which can further reduce energy consumption. This paper provides a survey of international electric storage water heater test procedures and efficiency metrics which can serve as a reference for comparison with proposed geyser standards and ratings in South Africa. Additionally it provides a sample of efficiency technologies employed to improve the efficiency of electric storage water heaters, and outlines programs to promote adoption of improved efficiency. Finally, it surveys current programs used to promote HPWH and considers the potential for this technology to address peak demand more effectively than reduction of standby losses alone

  18. An Automatic Safety Control for Immersion Water Heater | Enokela ...

    African Journals Online (AJOL)

    The heating of liquids, especially water, is carried out in the homes and industries for various reasons. The domestic water heater has become a near- ubiquitous appliance in the Nigerian homes. An important source of concern with this appliance is the frequent possibility of outbreak of fire due to negligence on the part of ...

  19. 75 FR 20111 - Energy Conservation Program: Energy Conservation Standards for Residential Water Heaters, Direct...

    Science.gov (United States)

    2010-04-16

    ... Energy 10 CFR Part 430 Energy Conservation Program: Energy Conservation Standards for Residential Water... Energy Conservation Program: Energy Conservation Standards for Residential Water Heaters, Direct Heating... conservation standards for residential water heaters (other than tabletop and electric instantaneous models...

  20. Development of an Accurate Feed-Forward Temperature Control Tankless Water Heater

    Energy Technology Data Exchange (ETDEWEB)

    David Yuill

    2008-06-30

    The following document is the final report for DE-FC26-05NT42327: Development of an Accurate Feed-Forward Temperature Control Tankless Water Heater. This work was carried out under a cooperative agreement from the Department of Energy's National Energy Technology Laboratory, with additional funding from Keltech, Inc. The objective of the project was to improve the temperature control performance of an electric tankless water heater (TWH). The reason for doing this is to minimize or eliminate one of the barriers to wider adoption of the TWH. TWH use less energy than typical (storage) water heaters because of the elimination of standby losses, so wider adoption will lead to reduced energy consumption. The project was carried out by Building Solutions, Inc. (BSI), a small business based in Omaha, Nebraska. BSI partnered with Keltech, Inc., a manufacturer of electric tankless water heaters based in Delton, Michigan. Additional work was carried out by the University of Nebraska and Mike Coward. A background study revealed several advantages and disadvantages to TWH. Besides using less energy than storage heaters, TWH provide an endless supply of hot water, have a longer life, use less floor space, can be used at point-of-use, and are suitable as boosters to enable alternative water heating technologies, such as solar or heat-pump water heaters. Their disadvantages are their higher cost, large instantaneous power requirement, and poor temperature control. A test method was developed to quantify performance under a representative range of disturbances to flow rate and inlet temperature. A device capable of conducting this test was designed and built. Some heaters currently on the market were tested, and were found to perform quite poorly. A new controller was designed using model predictive control (MPC). This control method required an accurate dynamic model to be created and required significant tuning to the controller before good control was achieved. The MPC

  1. Measure Guideline: Heat Pump Water Heaters in New and Existing Homes

    Energy Technology Data Exchange (ETDEWEB)

    Shapiro, C.; Puttagunta, S.; Owens, D.

    2012-02-01

    This Building America Measure Guideline is intended for builders, contractors, homeowners, and policy-makers. This document is intended to explore the issues surrounding heat pump water heaters (HPWHs) to ensure that homeowners and contractors have the tools needed to appropriately and efficiently install HPWHs. Heat pump water heaters (HPWHs) promise to significantly reduce energy consumption for domestic hot water (DHW) over standard electric resistance water heaters (ERWHs). While ERWHs perform with energy factors (EFs) around 0.9, new HPWHs boast EFs upwards of 2.0. High energy factors in HPWHs are achieved by combining a vapor compression system, which extracts heat from the surrounding air at high efficiencies, with electric resistance element(s), which are better suited to meet large hot water demands. Swapping ERWHs with HPWHs could result in roughly 50% reduction in water heating energy consumption for 35.6% of all U.S. households. This Building America Measure Guideline is intended for builders, contractors, homeowners, and policy-makers. While HPWHs promise to significantly reduce energy use for DHW, proper installation, selection, and maintenance of HPWHs is required to ensure high operating efficiency and reliability. This document is intended to explore the issues surrounding HPWHs to ensure that homeowners and contractors have the tools needed to appropriately and efficiently install HPWHs. Section 1 of this guideline provides a brief description of HPWHs and their operation. Section 2 highlights the cost and energy savings of HPWHs as well as the variables that affect HPWH performance, reliability, and efficiency. Section 3 gives guidelines for proper installation and maintenance of HPWHs, selection criteria for locating HPWHs, and highlights of important differences between ERWH and HPWH installations. Throughout this document, CARB has included results from the evaluation of 14 heat pump water heaters (including three recently released HPWH

  2. Research and development of a high efficiency gas-fired water heater. Volume 2. Task reports

    Energy Technology Data Exchange (ETDEWEB)

    Vasilakis, A.D.; Pearson, J.F.; Gerstmann, J.

    1980-01-01

    Design and development of a cost-effective high efficiency gas-fired water heater to attain a service efficiency of 70% (including the effect of exfiltration) and a service efficiency of 78% (excluding exfiltration) for a 75 GPD draw at a 90/sup 0/F temperature rise, with a stored water to conditioned air temperature difference of 80/sup 0/F, are described in detail. Based on concept evaluation, a non-powered natural draft water heater was chosen as the most cost-effective design to develop. The projected installed cost is $374 compared to $200 for a conventional unit. When the project water heater is compared to a conventional unit, it has a payback of 3.7 years and life cycle savings of $350 to the consumer. A prototype water heater was designed, constructed, and tested. When operated with sealed combustion, the unit has a service efficiency of 66.4% (including the effect of exfiltration) below a burner input of 32,000 Btu/h. In the open combustion configuration, the unit operated at a measured efficiency of 66.4% Btu/h (excluding exfiltration). This compares with a service efficiency of 51.3% for a conventional water heater and 61% for a conventional high efficiency unit capable of meeting ASHRAE 90-75. Operational tests showed the unit performed well with no evidence of stacking or hot spots. It met or exceeded all capacity or usage tests specified in the program test plan and met all emission goals. Future work will concentrate on designing, building, and testing pre-production units. It is anticipated that both sealed combustion and open draft models will be pursued.

  3. Marketing and promoting solar water heaters to home builders

    Energy Technology Data Exchange (ETDEWEB)

    Keller, C.; Ghent, P.

    1999-12-06

    This is the final report of a four-task project to develop a marketing plan designed for businesses interested in marketing solar water heaters in the new home industry. This report outlines suggested marketing communication materials and other promotional tools focused on selling products to the new home builder. Information relevant to promoting products to the new home buyer is also included.

  4. Demand Response Performance of GE Hybrid Heat Pump Water Heater

    Energy Technology Data Exchange (ETDEWEB)

    Widder, Sarah H.; Parker, Graham B.; Petersen, Joseph M.; Baechler, Michael C.

    2013-07-01

    This report describes a project to evaluate and document the DR performance of HPWH as compared to ERWH for two primary types of DR events: peak curtailments and balancing reserves. The experiments were conducted with GE second-generation “Brillion”-enabled GeoSpring hybrid water heaters in the PNNL Lab Homes, with one GE GeoSpring water heater operating in “Standard” electric resistance mode to represent the baseline and one GE GeoSpring water heater operating in “Heat Pump” mode to provide the comparison to heat pump-only demand response. It is expected that “Hybrid” DR performance, which would engage both the heat pump and electric elements, could be interpolated from these two experimental extremes. Signals were sent simultaneously to the two water heaters in the side-by-side PNNL Lab Homes under highly controlled, simulated occupancy conditions. This report presents the results of the evaluation, which documents the demand-response capability of the GE GeoSpring HPWH for peak load reduction and regulation services. The sections describe the experimental protocol and test apparatus used to collect data, present the baselining procedure, discuss the results of the simulated DR events for the HPWH and ERWH, and synthesize key conclusions based on the collected data.

  5. Solar water heaters in China: A new day dawning

    NARCIS (Netherlands)

    Han, Jingyi; Mol, A.P.J.; Lu, Y.

    2010-01-01

    Solar thermal utilization, especially the application of solar water heater technology, has developed rapidly in China in recent decades. Manufacturing and marketing developments have been especially strong in provinces such as Zhejiang, Shandong and Jiangsu. This paper takes Zhejiang, a relatively

  6. Marketers across the U. S. find propane water heaters a viable load-builder

    Energy Technology Data Exchange (ETDEWEB)

    1993-11-01

    Rather than the usual annual update reporting on specific models and upgrades from water heater manufacturers, the authors concentrate on water heater marketing in the propane industry. Some of the marketing strategies they present are the result of exclusive interviews and some are recaps of water heater marketing plans mentioned in the AFRED study, but marketers across the country are unanimous in their appreciation of the lowly water heater.

  7. Evaluation of the Demand Response Performance of Electric Water Heaters

    Energy Technology Data Exchange (ETDEWEB)

    Mayhorn, Ebony T. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Widder, Sarah H. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Parker, Steven A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Pratt, Richard M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Chassin, Forrest S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-03-17

    The purpose of this project is to verify or refute many of the concerns raised by utilities regarding the ability of large tank HPWHs to perform DR by measuring the performance of HPWHs compared to ERWHs in providing DR services. perform DR by measuring the performance of HPWHs compared to ERWHs in providing DR services. This project was divided into three phases. Phase 1 consisted of week-long laboratory experiments designed to demonstrate technical feasibility of individual large-tank HPWHs in providing DR services compared to large-tank ERWHs. In Phase 2, the individual behaviors of the water heaters were then extrapolated to a population by first calibrating readily available water heater models developed in GridLAB-D simulation software to experimental results obtained in Phase 1. These models were used to simulate a population of water heaters and generate annual load profiles to assess the impacts on system-level power and residential load curves. Such population modeling allows for the inherent and permanent load reduction accomplished by the more efficient HPWHs to be considered, in addition to the temporal DR services the water heater can provide by switching ON or OFF as needed by utilities. The economic and emissions impacts of using large-tank water heaters in DR programs are then analyzed from the utility and consumer perspective, based on National Impacts Analysis in Phase 3. Phase 1 is discussed in this report. Details on Phases 2 and 3 can be found in the companion report (Cooke et al. 2014).

  8. Laboratory Performance Evaluation of Residential Integrated Heat Pump Water Heaters

    Energy Technology Data Exchange (ETDEWEB)

    Sparn, B.; Hudon, K.; Christensen, D.

    2014-06-01

    This paper explores the laboratory performance of five integrated Heat Pump Water Heaters (HPWHs) across a wide range of operating conditions representative of U.S. climate regions. HPWHs are expected to provide significant energy savings in certain climate zones when compared to typical electric resistance water heaters. Results show that this technology is a viable option in most climates, but differences in control schemes and design features impact the performance of the units tested. Tests were conducted to map heat pump performance across the operating range and to determine the logic used to control the heat pump and the backup electric heaters. Other tests performed include two unique draw profile tests, reduced air flow performance tests and the standard DOE rating tests. The results from all these tests are presented here for all five units tested. The results of these tests will be used to improve the EnergyPlus heat pump water heater for use in BEopt™ whole-house building simulations.

  9. Laboratory Performance Evaluation of Residential Integrated Heat Pump Water Heaters

    Energy Technology Data Exchange (ETDEWEB)

    Sparn, B.; Hudon, K.; Christensen, D.

    2014-06-01

    This paper explores the laboratory performance of five integrated Heat Pump Water Heaters (HPWHs) across a wide range of operating conditions representative of US climate regions. HPWHs are expected to provide significant energy savings in certain climate zones when compared to typical electric resistance water heaters. Results show that this technology is a viable option in most climates, but differences in control schemes and design features impact the performance of the units tested. Tests were conducted to map heat pump performance across the operating range and to determine the logic used to control the heat pump and the backup electric heaters. Other tests performed include two unique draw profile tests, reduced air flow performance tests and the standard DOE rating tests. The results from all these tests are presented here for all five units tested. The results of these tests will be used to improve the EnergyPlus heat pump water heater for use in BEopt(tm) whole-house building simulations.

  10. Scheduling of Domestic Water Heater Power Demand for Maximizing PV Self-Consumption Using Model Predictive Control

    DEFF Research Database (Denmark)

    Sossan, Fabrizio; Kosek, Anna Magdalena; Martinenas, Sergejus

    2013-01-01

    This paper presents a model predictive control (MPC) strategy for maximizing photo-voltaic (PV) selfconsumption in a household context exploiting the flexible demand of an electric water heater. The predictive controller uses a water heater model and forecast of the hot Water consumption in order...... to predict the future temperature of the water and it manages its state (on and off) according to the forecasted PV production, which are computed starting from forecast of the solar irradiance. Simulations for the proof of concept and for validating the proposed control strategy are proposed. Results...... of the control approach are compared with a traditional thermostatic controller using historical measurements of a 10 kW PV installation. Economic results based on the Italian self consumption tariffs are also reported. The model of the water heater complex is a mixed grey and white box and its parameters have...

  11. Recovery Act: Water Heater ZigBee Open Standard Wireless Controller

    Energy Technology Data Exchange (ETDEWEB)

    Butler, William P. [Emerson Electric Co., St. Louis, MO (United States); Buescher, Tom [Emerson Electric Co., St. Louis, MO (United States)

    2014-04-30

    The objective of Emerson's Water Heater ZigBee Open Standard Wireless Controller is to support the DOE's AARA priority for Clean, Secure Energy by designing a water heater control that levels out residential and small business peak electricity demand through thermal energy storage in the water heater tank.

  12. Field Performance of Heat Pump Water Heaters in the Northeast

    Energy Technology Data Exchange (ETDEWEB)

    Shapiro, Carl [Consortium for Advanced Residential Buildings, Norfolk, CT (United States); Puttagunta, Srikanth [Consortium for Advanced Residential Buildings, Norfolk, CT (United States)

    2016-02-05

    Heat pump water heaters (HPWHs) are finally entering the mainstream residential water heater market. Potential catalysts are increased consumer demand for higher energy efficiency electric water heating and a new Federal water heating standard that effectively mandates use of HPWHs for electric storage water heaters with nominal capacities greater than 55 gallons. When compared to electric resistance water heating, the energy and cost savings potential of HPWHs is tremendous. Converting all electric resistance water heaters to HPWHs could save American consumers 7.8 billion dollars annually ($182 per household) in water heating operating costs and cut annual residential source energy consumption for water heating by 0.70 quads. Steven Winter Associates, Inc. embarked on one of the first in situ studies of these newly released HPWH products through a partnership with two sponsoring electric utility companies, National Grid and NSTAR, and one sponsoring energy efficiency service program administrator, Cape Light Compact. Recent laboratory studies have measured performance of HPWHs under various operating conditions, but publically available field studies have not been as available. This evaluation attempts to provide publicly available field data on new HPWHs by monitoring the performance of three recently released products (General Electric GeoSpring(TM), A.O. Smith Voltex(R), and Stiebel Eltron Accelera(R) 300). Fourteen HPWHs were installed in Massachusetts and Rhode Island and monitored for over a year. Of the 14 units, ten were General Electric models (50 gallon units), two were Stiebel Eltron models (80 gallon units), and two were A.O. Smith models (one 60-gallon and one 80-gallon unit).

  13. Field Performance of Heat Pump Water Heaters in the Northeast

    Energy Technology Data Exchange (ETDEWEB)

    Shapiro, C.; Puttagunta, S.

    2013-08-01

    Heat pump water heaters (HPWHs) are finally entering the mainstream residential water heater market. Potential catalysts are increased consumer demand for higher energy efficiency electric water heating and a new Federal water heating standard that effectively mandates use of HPWHs for electric storage water heaters with nominal capacities greater than 55 gallons. When compared to electric resistance water heating, the energy and cost savings potential of HPWHs is tremendous. Converting all electric resistance water heaters to HPWHs could save American consumers 7.8 billion dollars annually ($182 per household) in water heating operating costs and cut annual residential source energy consumption for water heating by 0.70 quads. Steven Winter Associates, Inc. embarked on one of the first in situ studies of these newly released HPWH products through a partnership with two sponsoring electric utility companies, National Grid and NSTAR, and one sponsoring energy efficiency service program administrator, Cape Light Compact. Recent laboratory studies have measured performance of HPWHs under various operating conditions, but publicly available field studies have not been as available. This evaluation attempts to provide publicly available field data on new HPWHs by monitoring the performance of three recently released products (General Electric GeoSpring(tm), A.O. Smith Voltex(r), and Stiebel Eltron Accelera(r)300). Fourteen HPWHs were installed in Massachusetts and Rhode Island and monitored for over a year. Of the 14 units, ten were General Electric models (50 gallon units), two were Stiebel Eltron models (80 gallon units), and two were A.O. Smith models (one 60-gallon and one 80-gallon unit).

  14. COST-EFFECTIVENESS ANALYSIS OF ALTERNATIVE WATER HEATER SYSTEMS OPERATING WITH UNRELIABLE WATER SUPPLIES

    OpenAIRE

    Arif Yurtsev; Jenkins, Glenn P.

    2015-01-01

    This paper reports on a cost-effectiveness analysis of four types of water heating systems operating in a situation where there is an unreliable water supply. These systems are electric water heating, a solar water heating system (SWHS) with electricity back-up, the SWHS with an LPG water heater, and an LPG water heater alone. It is found that in the conditions of North Cyprus, that an SWHS with an LPG heater back-up is the most cost-effective, most convenient and most environmentally friendl...

  15. Should Fermi Have Secured his Water Heater Against Earthquakes?

    Science.gov (United States)

    Brooks, E. M.; Diggory, M.; Gomez, E.; Salaree, A.; Schmid, M.; Saloor, N.; Stein, S. A.

    2015-12-01

    A common student response to quantitative questions in science with no obvious answer is "I have no idea." Often these questions can be addressed by Fermi estimation, in which an apparently difficult-to-estimate quantity for which one has little intuitive sense can be sensibly estimated by combining order of magnitude estimates of easier-to-estimate quantities. Although this approach is most commonly used for numerical estimates, it can also be applied to issues combining both science and policy. Either application involves dividing an issue into tractable components and addressing them separately. To learn this method, our natural hazard policy seminar considered a statement by the Illinois Emergency Management Agency that homeowners should secure water heaters to prevent them from being damaged by earthquakes. We divided this question into subtopics, researched each, and discussed them weekly to reach a synthesis. We used a simple model to estimate the net benefit, the difference between the expected value of damage and the cost of securing a water heater. This benefit is positive, indicating that securing is worthwhile, only if the probability of damage during the heater's life is relatively large, approximately 1 - 10%. To assess whether the actual probability is likely to be this high, we assume that major water heater damage is likely only for shaking with MMI intensity VIII ("heavy furniture overturned") or greater. Intensity data for the past 200 years of Illinois earthquakes show that this level was reached only in the very southernmost part of the state for the 1811-1812 New Madrid earthquakes. As expected, the highest known shaking generally decreases northward toward Chicago. This history is consistent with the fact that we find no known cases of earthquake-toppled water heaters in Illinois. We compared the rate of return on securing a water heater in Chicago to buying a lottery ticket when the jackpot is large, and found that the latter would be a

  16. Residential hot water distribution systems: Roundtablesession

    Energy Technology Data Exchange (ETDEWEB)

    Lutz, James D.; Klein, Gary; Springer, David; Howard, Bion D.

    2002-08-01

    Residential building practice currently ignores the lossesof energy and water caused by the poor design of hot water systems. Theselosses include: combustion and standby losses from water heaters, thewaste of water (and energy) while waiting for hot water to get to thepoint of use; the wasted heat as water cools down in the distributionsystem after a draw; heat losses from recirculation systems and thediscarded warmth of waste water as it runs down the drain. Severaltechnologies are available that save energy (and water) by reducing theselosses or by passively recovering heat from wastewater streams and othersources. Energy savings from some individual technologies are reported tobe as much as 30 percent. Savings calculations of prototype systemsincluding bundles of technologies have been reported above 50 percent.This roundtable session will describe the current practices, summarizethe results of past and ongoing studies, discuss ways to think about hotwater system efficiency, and point to areas of future study. We will alsorecommend further steps to reduce unnecessary losses from hot waterdistribution systems.

  17. Dynamic modeling of an air source heat pump water heater

    OpenAIRE

    Fardoun, Farouk; Ibrahim, Oussama; Zoughaib, Assaad

    2011-01-01

    International audience; This paper presents a dynamic simulation model to predict the performance of an air source heat pump water heater (ASHPWH). The mathematical model consists of submodels of the basic system components i.e. evaporator, condenser, compressor, and expansion valve. These submodels were built based on fundamental principles of heat transfer, thermodynamics, fluid mechanics, empirical relationships and manufacturer's data as necessary. The model simulation was carried out usi...

  18. Water heater temperature set point and water use patterns influence Legionella pneumophila and associated microorganisms at the tap.

    Science.gov (United States)

    Rhoads, William J; Ji, Pan; Pruden, Amy; Edwards, Marc A

    2015-12-01

    Lowering water heater temperature set points and using less drinking water are common approaches to conserving water and energy; yet, there are discrepancies in past literature regarding the effects of water heater temperature and water use patterns on the occurrence of opportunistic pathogens, in particular Legionella pneumophila. Our objective was to conduct a controlled, replicated pilot-scale investigation to address this knowledge gap using continuously recirculating water heaters to examine five water heater set points (39-58 °C) under three water use conditions. We hypothesized that L. pneumophila levels at the tap depend on the collective influence of water heater temperature, flow frequency, and the resident plumbing ecology. We confirmed temperature setting to be a critical factor in suppressing L. pneumophila growth both in continuously recirculating hot water lines and at distal taps. For example, at 51 °C, planktonic L. pneumophila in recirculating lines was reduced by a factor of 28.7 compared to 39 °C and was prevented from re-colonizing biofilm. However, L. pneumophila still persisted up to 58 °C, with evidence that it was growing under the conditions of this study. Further, exposure to 51 °C water in a low-use tap appeared to optimally select for L. pneumophila (e.g., 125 times greater numbers than in high-use taps). We subsequently explored relationships among L. pneumophila and other ecologically relevant microbes, noting that elevated temperature did not have a general disinfecting effect in terms of total bacterial numbers. We documented the relationship between L. pneumophila and Legionella spp., and noted several instances of correlations with Vermamoeba vermiformis, and generally found that there is a dynamic relationship with this amoeba host over the range of temperatures and water use frequencies examined. Our study provides a new window of understanding into the microbial ecology of potable hot water systems and helps to resolve

  19. LARGO hot water system thermal performance test report

    Science.gov (United States)

    1978-01-01

    The thermal performance tests and results on the LARGO Solar Hot Water System under natural environmental conditions is presented. Some objectives of these evaluations are to determine the amount of energy collected, the amount of energy delivered to the household as contributed by solar power supplied to operate the system and auxiliary power to maintain tank temperature at proper level, overall system efficiency and to determine temperature distribution within the tank. The Solar Hot Water system is termed a Dump-type because of the draining system for freeze protection. The solar collector is a single glazed flat plate. An 82-gallon domestic water heater is provided as the energy storage vessel. Water is circulated through the collector and water heater by a 5.3 GPM capacity pump, and control of the pump motor is achieved by a differential temperature controller.

  20. In situ Tuff water migration/heater experiment

    Science.gov (United States)

    Johnstone, J. K.; Hadley, G. R.; Waymire, D. R.

    1985-03-01

    The results of the In Situ Tuff Water Migration/Heater Experiment operated in the welded portion of the Grouse Canyon Member of the Belted Range Tuff in U12g-tunnel (G-Tunnel) on the Nevada Test Site are summarized. The experiment was located approximately 400 m below the surface and 200 m above the water table in nearly saturated rock. The experiment was designed to provide an initial assessment of the thermally induced behavior of the potentially large volumes of water (approx. 25 vol % in this case) available in saturated or nearly saturated tuffaceous rocks. Instruments in the water collection cavities, including water depth gages, pH probes, humidity gages, and pressure transducers measured some properties of the collected water. Other holes in the array were instrumented to measure temperature profiles, thermally induced stress, and one provided a test bed for a continuously operating laser interferometer for measuring thermally induced rock displacements. Initial analysis of the water generation rate data in the heater hole, assuming a one-dimensional evaporation front/vapor diffusion model, provided good qualitative agreement.

  1. Tool for Generating Realistic Residential Hot Water Event Schedules: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Hendron, B.; Burch, J.; Barker, G.

    2010-08-01

    The installed energy savings for advanced residential hot water systems can depend greatly on detailed occupant use patterns. Quantifying these patterns is essential for analyzing measures such as tankless water heaters, solar hot water systems with demand-side heat exchangers, distribution system improvements, and recirculation loops. This paper describes the development of an advanced spreadsheet tool that can generate a series of year-long hot water event schedules consistent with realistic probability distributions of start time, duration and flow rate variability, clustering, fixture assignment, vacation periods, and seasonality. This paper also presents the application of the hot water event schedules in the context of an integral-collector-storage solar water heating system in a moderate climate.

  2. Laboratory Evaluation of Gas-Fired Tankless and Storage Water Heater Approaches to Combination Water and Space Heating

    Energy Technology Data Exchange (ETDEWEB)

    Kingston, T.; Scott, S.

    2013-03-01

    Homebuilders are exploring more cost effective combined space and water heating systems (combo systems) with major water heater manufacturers that are offering pre-engineered forced air space heating combo systems. In this project, unlike standardized tests, laboratory tests were conducted that subjected condensing tankless and storage water heater based combo systems to realistic, coincidental space and domestic hot water loads with the following key findings: 1) The tankless combo system maintained more stable DHW and space heating temperatures than the storage combo system. 2) The tankless combo system consistently achieved better daily efficiencies (i.e. 84%-93%) than the storage combo system (i.e. 81%- 91%) when the air handler was sized adequately and adjusted properly to achieve significant condensing operation. When condensing operation was not achieved, both systems performed with lower (i.e. 75%-88%), but similar efficiencies. 3) Air handlers currently packaged with combo systems are not designed to optimize condensing operation. More research is needed to develop air handlers specifically designed for condensing water heaters. 4) System efficiencies greater than 90% were achieved only on days where continual and steady space heating loads were required with significant condensing operation. For days where heating was more intermittent, the system efficiencies fell below 90%.

  3. Development and Validation of a Gas-Fired Residential Heat Pump Water Heater - Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Michael Garrabrant; Roger Stout; Paul Glanville; Janice Fitzgerald; Chris Keinath

    2013-01-21

    For gas-fired residential water heating, the U.S. and Canada is predominantly supplied by minimum efficiency storage water heaters with Energy Factors (EF) in the range of 0.59 to 0.62. Higher efficiency and higher cost ($700 - $2,000) options serve about 15% of the market, but still have EFs below 1.0, ranging from 0.65 to 0.95. To develop a new class of water heating products that exceeds the traditional limit of thermal efficiency, the project team designed and demonstrated a packaged water heater driven by a gas-fired ammonia-water absorption heat pump. This gas-fired heat pump water heater can achieve EFs of 1.3 or higher, at a consumer cost of $2,000 or less. Led by Stone Mountain Technologies Inc. (SMTI), with support from A.O. Smith, the Gas Technology Institute (GTI), and Georgia Tech, the cross-functional team completed research and development tasks including cycle modeling, breadboard evaluation of two cycles and two heat exchanger classes, heat pump/storage tank integration, compact solution pump development, combustion system specification, and evaluation of packaged prototype GHPWHs. The heat pump system extracts low grade heat from the ambient air and produces high grade heat suitable for heating water in a storage tank for domestic use. Product features that include conventional installation practices, standard footprint and reasonable economic payback, position the technology to gain significant market penetration, resulting in a large reduction of energy use and greenhouse gas emissions from domestic hot water production.

  4. Urban renovation of the hot water supply system

    Directory of Open Access Journals (Sweden)

    Taraday Oleksandr

    2017-01-01

    Full Text Available Issues related to improving the reliability of hot water supply systems are considered. Currently, centralized hot water supply systems are in an emergency condition due to the fact that the external networks are made of black pipes without anticorrosive coatings. A fundamental difference between hot water supply systems and heating systems is the nature of black metal corrosion. The purpose of this article is to conduct a research of the state of hot water supply systems and consider options for their recovery. The options suggested for restoration of hot water supply systems in cities and settlements of Ukraine are the following: complete replacement of failed networks with new pre-insulated plastic pipelines; refusal from external networks of centralized hot water supply systems and a central heat point with the installation of individual heat points in each house; decentralization of hot water supply systems by installing electric water heaters. A technical and economic comparison of these options is carried out, and the advantages and disadvantages of each option are considered. The arrangement of a set of individual heat points instead of one central point cannot be considered as the recommended method, because of the need for large additional costs for the reconstruction of heating, water supply and electricity supply systems. The most technically and economically justified method from the considered renovation methods of hot water supply systems is the complete replacement of failed steel pipelines with new nonmetallic pre-insulated structures.

  5. 78 FR 2340 - Energy Conservation Program: Test Procedures for Residential Water Heaters and Commercial Water...

    Science.gov (United States)

    2013-01-11

    ... energy conservation standards adopted pursuant to EPCA, and for making representations about the... product literature, product markings, product marketing, or product installation and operation..., and allow for an accurate representation of efficiency of a wide range of different water heaters...

  6. High Efficiency R-744 Commercial Heat Pump Water Heaters

    Energy Technology Data Exchange (ETDEWEB)

    Elbel, Dr. Stefan W.; Petersen, Michael

    2013-04-25

    The project investigated the development and improvement process of a R744 (CO2) commercial heat pump water heater (HPWH) package of approximately 35 kW. The improvement process covered all main components of the system. More specific the heat exchangers (Internal heat exchanger, Evaporator, Gas cooler) as well as the expansion device and the compressor were investigated. In addition, a comparison to a commercially available baseline R134a unit of the same capacity and footprint was made in order to compare performance as well as package size reduction potential.

  7. Research and development of a heat-pump water heater. Volume 2. R and D task reports

    Energy Technology Data Exchange (ETDEWEB)

    Dunning, R.L.; Amthor, F.R.; Doyle, E.J.

    1978-08-01

    The heat pump water heater is a device that works much like a window air conditioner except that heat from the home is pumped into a water tank rather than to the outdoors. The objective established for the device is to operate with a Coefficient of Performance (COP) of 3 or, an input of one unit of electric energy would create three units of heat energy in the form of hot water. With such a COP, the device would use only one-third the energy and at one-third the cost of a standard resistance water heater. This Volume 2 contains the final reports of the three major tasks performed in Phase I. In Task 2, a market study identifies the future market and selects an initial target market and channel of distribution, all based on an analysis of the parameters affecting feasibility of the device and the factors that will affect its market acceptance. In the Task 3 report, the results of a design and test program to arrive at final designs of heat pumps for both new water heaters and for retrofitting existing water heaters are presented. In the Task 4 report, a plan for an extensive field demonstration involving use in actual homes is presented. Volume 1 contains a final summary report of the information in Volume 2.

  8. Energy Factor Analysis for Gas Heat Pump Water Heaters

    Energy Technology Data Exchange (ETDEWEB)

    Gluesenkamp, Kyle R [ORNL

    2016-01-01

    Gas heat pump water heaters (HPWHs) can improve water heating efficiency with zero GWP and zero ODP working fluids. The energy factor (EF) of a gas HPWH is sensitive to several factors. In this work, expressions are derived for EF of gas HPWHs, as a function of heat pump cycle COP, tank heat losses, burner efficiency, electrical draw, and effectiveness of supplemental heat exchangers. The expressions are used to investigate the sensitivity of EF to each parameter. EF is evaluated on a site energy basis (as used by the US DOE for rating water heater EF), and a primary energy-basis energy factor (PEF) is also defined and included. Typical ranges of values for the six parameters are given. For gas HPWHs, using typical ranges for component performance, EF will be 59 80% of the heat pump cycle thermal COP (for example, a COP of 1.60 may result in an EF of 0.94 1.28). Most of the reduction in COP is due to burner efficiency and tank heat losses. Gas-fired HPWHs are theoretically be capable of an EF of up to 1.7 (PEF of 1.6); while an EF of 1.1 1.3 (PEF of 1.0 1.1) is expected from an early market entry.

  9. Simple Retrofit High-Efficiency Natural Gas Water Heater Field Test

    Energy Technology Data Exchange (ETDEWEB)

    Schoenbauer, Ben [NorthernSTAR, St. Paul, MN (United States)

    2017-03-28

    High performance water heaters are typically more time consuming and costly to install in retrofit applications, making high performance water heaters difficult to justify economically. However, recent advancements in high performance water heaters have targeted the retrofit market, simplifying installations and reducing costs. Four high efficiency natural gas water heaters designed specifically for retrofit applications were installed in single-family homes along with detailed monitoring systems to characterize their savings potential, their installed efficiencies, and their ability to meet household demands. The water heaters tested for this project were designed to improve the cost-effectiveness and increase market penetration of high efficiency water heaters in the residential retrofit market. The retrofit high efficiency water heaters achieved their goal of reducing costs, maintaining savings potential and installed efficiency of other high efficiency water heaters, and meeting the necessary capacity in order to improve cost-effectiveness. However, the improvements were not sufficient to achieve simple paybacks of less than ten years for the incremental cost compared to a minimum efficiency heater. Significant changes would be necessary to reduce the simple payback to six years or less. Annual energy savings in the range of $200 would also reduce paybacks to less than six years. These energy savings would require either significantly higher fuel costs (greater than $1.50 per therm) or very high usage (around 120 gallons per day). For current incremental costs, the water heater efficiency would need to be similar to that of a heat pump water heater to deliver a six year payback.

  10. Simple Retrofit High-Efficiency Natural Gas Water Heater Field Test

    Energy Technology Data Exchange (ETDEWEB)

    Schoenbauer, Ben [NorthernSTAR, St. Paul, MN (United States)

    2017-03-01

    High-performance water heaters are typically more time consuming and costly to install in retrofit applications, making high performance water heaters difficult to justify economically. However, recent advancements in high performance water heaters have targeted the retrofit market, simplifying installations and reducing costs. Four high efficiency natural gas water heaters designed specifically for retrofit applications were installed in single-family homes along with detailed monitoring systems to characterize their savings potential, their installed efficiencies, and their ability to meet household demands. The water heaters tested for this project were designed to improve the cost-effectiveness and increase market penetration of high efficiency water heaters in the residential retrofit market. The retrofit high efficiency water heaters achieved their goal of reducing costs, maintaining savings potential and installed efficiency of other high efficiency water heaters, and meeting the necessary capacity in order to improve cost-effectiveness. However, the improvements were not sufficient to achieve simple paybacks of less than ten years for the incremental cost compared to a minimum efficiency heater. Significant changes would be necessary to reduce the simple payback to six years or less. Annual energy savings in the range of $200 would also reduce paybacks to less than six years. These energy savings would require either significantly higher fuel costs (greater than $1.50 per therm) or very high usage (around 120 gallons per day). For current incremental costs, the water heater efficiency would need to be similar to that of a heat pump water heater to deliver a six year payback.

  11. Hot embossing and thermal bonding of poly(methyl methacrylate) microfluidic chips using positive temperature coefficient ceramic heater.

    Science.gov (United States)

    Wang, Xia; Zhang, Luyan; Chen, Gang

    2011-11-01

    As a self-regulating heating device, positive temperature coefficient ceramic heater was employed for hot embossing and thermal bonding of poly(methyl methacrylate) microfluidic chip because it supplied constant-temperature heating without electrical control circuits. To emboss a channel plate, a piece of poly(methyl methacrylate) plate was sandwiched between a template and a microscopic glass slide on a positive temperature coefficient ceramic heater. All the assembled components were pressed between two elastic press heads of a spring-driven press while a voltage was applied to the heater for 10 min. Subsequently, the embossed poly(methyl methacrylate) plate bearing negative relief of channel networks was bonded with a piece of poly(methyl methacrylate) cover sheet to obtain a complete microchip using a positive temperature coefficient ceramic heater and a spring-driven press. High quality microfluidic chips fabricated by using the novel embossing/bonding device were successfully applied in the electrophoretic separation of three cations. Positive temperature coefficient ceramic heater indicates great promise for the low-cost production of poly(methyl methacrylate) microchips and should find wide applications in the fabrication of other thermoplastic polymer microfluidic devices.

  12. Reliable, Economic, Efficient CO2 Heat Pump Water Heater for North America

    Energy Technology Data Exchange (ETDEWEB)

    Radcliff, Thomas D; Sienel, Tobias; Huff, Hans-Joachim; Thompson, Adrian; Sadegh, Payman; Olsommer, Benoit; Park, Young

    2006-12-31

    Adoption of heat pump water heating technology for commercial hot water could save up to 0.4 quads of energy and 5 million metric tons of CO2 production annually in North America, but industry perception is that this technology does not offer adequate performance or reliability and comes at too high of a cost. Development and demonstration of a CO2 heat pump water heater is proposed to reduce these barriers to adoption. Three major themes are addressed: market analysis to understand barriers to adoption, use of advanced reliability models to design optimum qualification test plans, and field testing of two phases of water heater prototypes. Market experts claim that beyond good performance, market adoption requires 'drop and forget' system reliability and a six month payback of first costs. Performance, reliability and cost targets are determined and reliability models are developed to evaluate the minimum testing required to meet reliability targets. Three phase 1 prototypes are designed and installed in the field. Based on results from these trials a product specification is developed and a second phase of five field trial units are built and installed. These eight units accumulate 11 unit-years of service including 15,650 hours and 25,242 cycles of compressor operation. Performance targets can be met. An availability of 60% is achieved and the capability to achieve >90% is demonstrated, but overall reliability is below target, with an average of 3.6 failures/unit-year on the phase 2 demonstration. Most reliability issues are shown to be common to new HVAC products, giving high confidence in mature product reliability, but the need for further work to minimize leaks and ensure reliability of the electronic expansion valve is clear. First cost is projected to be above target, leading to an expectation of 8-24 month payback when substituted for an electric water heater. Despite not meeting all targets, arguments are made that an industry leader could

  13. Demonstration of a heat pump water heater. Volume 3. Design report

    Energy Technology Data Exchange (ETDEWEB)

    Sloane, B.D.; Krise, R.C.; Kent, D.D.

    1979-12-01

    Work performed during the pilot run manufacturing and laboratory testing stages of a heat pump water heater for residential installations is described. A general description of the heat pump water heater is provided, as are detailed discussions of individual components. Also included is a description of the pilot run manufacturing facility and experience, laboratory operations, and laboratory test data.

  14. Analysis of Large- Capacity Water Heaters in Electric Thermal Storage Programs

    Energy Technology Data Exchange (ETDEWEB)

    Cooke, Alan L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Anderson, David M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Winiarski, David W. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Carmichael, Robert T. [Cadeo Group, Washington D. C. (United States); Mayhorn, Ebony T. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Fisher, Andrew R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-03-17

    This report documents a national impact analysis of large tank heat pump water heaters (HPWH) in electric thermal storage (ETS) programs and conveys the findings related to concerns raised by utilities regarding the ability of large-tank heat pump water heaters to provide electric thermal storage services.

  15. CFD Study of Fluid Flow in an All-glass Evacuated Tube Solar Water Heater

    DEFF Research Database (Denmark)

    Ai, Ning; Fan, Jianhua; Li, Yumin

    2008-01-01

    Abstract: The all-glass evacuated tube solar water heater is one of the most widely used solar thermal technologies. The aim of the paper is to investigate fluid flow in the solar water heater by means of computational fluid dynamics (CFD). The investigation was carried out with a focus...

  16. Tankless water heaters fill the bill at fast-food restaurants

    Energy Technology Data Exchange (ETDEWEB)

    1988-02-01

    This article explains why Kentucky Fried Chicken has installed a PH-24 water heater. The tankless water heater meets the restaurant's criteria for space spacing, flow rates, certification and availability, and money saving efficiency. This article describes the system and its advantages.

  17. 16 CFR Appendix D4 to Part 305 - Water Heaters-Instantaneous-Gas

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Water Heaters-Instantaneous-Gas D4 Appendix...) Pt. 305, App. D4 Appendix D4 to Part 305—Water Heaters-Instantaneous-Gas Range Information CAPACITY FIRST HOUR RATING Range of Estimated Annual Operating Costs (Dollars/Year) Natural Gas ($/year) Low High...

  18. 78 FR 7394 - Notification of Proposed Production Activity; GE Appliances; Subzone 29C (Electric Water Heaters...

    Science.gov (United States)

    2013-02-01

    ..., including dishwashers, refrigerator- freezers, freezers, apparel washing machines and dryers, electric... (Electric Water Heaters), Louisville, KY GE Appliances, operator of Subzone 29C, submitted a notification of... involves the production of electric water heaters. Pursuant to 15 CFR 400.14(b) of the regulations, FTZ...

  19. Modeling patterns of hot water use in households

    Energy Technology Data Exchange (ETDEWEB)

    Lutz, J.D.; Liu, Xiaomin; McMahon, J.E. [and others

    1996-11-01

    This report presents a detailed model of hot water use patterns in individual household. The model improves upon an existing model by including the effects of four conditions that were previously unaccounted for: the absence of a clothes washer; the absence of a dishwasher; a household consisting of seniors only; and a household that does not pay for its own hot water use. Although these four conditions can significantly affect residential hot water use, and have been noted in other studies, this is the first time that they have been incorporated into a detailed model. This model allows detailed evaluation of the impact of potential efficiency standards for water heaters and other market transformation policies. 21 refs., 3 figs., 10 tabs.

  20. Modeling patterns of hot water use in households

    Energy Technology Data Exchange (ETDEWEB)

    Lutz, James D.; Liu, Xiaomin; McMahon, James E.; Dunham, Camilla; Shown, Leslie J.; McCure, Quandra T.

    1996-01-01

    This report presents a detailed model of hot water use patterns in individual households. The model improves upon an existing model by including the effects of four conditions that were previously unaccounted for: the absence of a clothes washer; the absence of a dishwasher; a household consisting of seniors only; and a household that does not pay for its own hot water use. Although these four conditions can significantly affect residential hot water use, and have been noted in other studies, this is the first time that they have been incorporated into a detailed model. This model allows detailed evaluation of the impact of potential efficiency standards for water heaters and other market transformation policies.

  1. Getting into hot water Problematizing hot water service demand: The case of Old Cairo

    Science.gov (United States)

    Culhane, Thomas Henry

    This dissertation analyzes hot water demand and service infrastructure in two neighboring but culturally distinct communities of the urban poor in the inner-city area of central Cairo. The communities are the Historic Islamic Cairo neighborhood of Darb Al Ahmar at the foot of Al-Azhar park, and the Zurayib neighborhood of Manshiyat Nasser where the Coptic Zabaleen Recyclers live. The study focuses on the demand side of the hot water issue and involves consideration of built-environment infrastructures providing piped water, electricity, bottled gas, sewage, and the support structures (wiring and plumbing) for consumer durables (appliances such as hot water heaters, stoves, refrigerators, air conditioners) as well as water pumps and water storage tanks. The study asks the questions "How do poor communities in Cairo value hot water" and "How do cost, infrastructure and cultural preferences affect which attributes of hot water service are most highly preferred?". To answer these questions household surveys based primarily on the World Bank LSMS modules were administered by professional survey teams from Darb Al Ahmar's Aga Khan Trust for Culture and the Zabaleen's local NGO "Spirit of Youth" in their adjacent conununities in and surrounding historic Cairo. In total 463 valid surveys were collected, (231 from Darb Al Ahmar, 232 from the Zabaleen). The surveys included a contingent valuation question to explore Willingness to Pay for improved hot water service; the surveys queried household assets as proxies for income. The dissertation's findings reveal that one quarter of the residents of Darb Al Ahmar and two-thirds of the residents of Manshiyet Nasser's Zabaleen lack conventional water heating service. Instead they employ various types of stoves and self-built contraptions to heat water, usually incurring considerable risk and opportunity costs. However the thesis explores the notion that this is rational "satisficing" behavior; despite the shortcomings of such self

  2. Heat pump water heater and method of making the same

    Science.gov (United States)

    Mei, Viung C.; Tomlinson, John J.; Chen, Fang C.

    2001-01-01

    An improved heat pump water heater wherein the condenser assembly of the heat pump is inserted into the water tank through an existing opening in the top of the tank, the assembly comprising a tube-in-a-tube construction with an elongated cylindrical outer body heat exchanger having a closed bottom with the superheated refrigerant that exits the compressor of the heat pump entering the top of the outer body. As the refrigerant condenses along the interior surface of the outer body, the heat from the refrigerant is transferred to the water through the outer body. The refrigerant then enters the bottom of an inner body coaxially disposed within the outer body and exits the top of the inner body into the refrigerant conduit leading into the expansion device of the heat pump. The outer body, in a second embodiment of the invention, acts not only as a heat exchanger but also as the sacrificial anode in the water tank by being constructed of a metal which is more likely to corrode than the metal of the tank.

  3. 75 FR 21981 - Energy Conservation Program: Energy Conservation Standards for Residential Water Heaters, Direct...

    Science.gov (United States)

    2010-04-27

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY 10 CFR Part 430 RIN 1904-AA90 Energy Conservation Program: Energy Conservation Standards for Residential Water Heaters, Direct Heating Equipment, and Pool Heaters Correction In rule document 2010-7611 beginning on...

  4. Commercial Absorption Heat Pump Water Heater: Beta Prototype Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Geoghegan, Patrick [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Ally, Moonis [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Sharma, Vishaldeep [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-10-14

    The Beta version of the Commercial Absorption Heat Pump (CAHP) water heater was evaluated in the environmental chambers at Oak Ridge National Laboratory. Ambient air conditions ranged from 17 to 75 oF and inlet water temperatures ranged from 100 to 120oF in order to capture trends in performance. The unit was operated under full fire (100%) and partial fire (55%). The unit was found to perform at 90% of the project goal at the design conditions of 47oF ambient and 100oF water temperatures. The trends across the full range of environmental conditions were as expected for ambient air temperatures above 32oF. Below this temperature and for the full fire condition, frost accumulated on the evaporator coil. In future work a defrost strategy will be enabled, the unit will be thoroughly cleaned of an oil contamination and the rectifier will be reconfigured in order to meet the design goals and have a field test unit ready in early 2017.

  5. Hot water tank for use with a combination of solar energy and heat-pump desuperheating

    Science.gov (United States)

    Andrews, J.W.

    1980-06-25

    A water heater or system is described which includes a hot water tank having disposed therein a movable baffle to function as a barrier between the incoming volume of cold water entering the tank and the volume of heated water entering the tank which is heated by the circulation of the cold water through a solar collector and/or a desuperheater of a heat pump so as to optimize the manner in which heat is imparted to the water in accordance to the demand on the water heater or system. A supplemental heater is also provided and it is connected so as to supplement the heating of the water in the event that the solar collector and/or desuperheater cannot impart all of the desired heat input into the water.

  6. Effect of heat recovery water heater system on the performance of residential split air conditioner using hydrocarbon refrigerant (HCR22)

    Science.gov (United States)

    Aziz, A.; Thalal; Amri, I.; Herisiswanto; Mainil, A. K.

    2017-09-01

    This This paper presents the performance of residential split air conditioner (RSAC) using hydrocarbon refrigerant (HCR22) as the effect on the use of heat recovery water heater system (HRWHS). In this study, RSAC was modified with addition of dummy condenser (trombone coil type) as heat recovery water heater system (HRWHS). This HRWHS is installed between a compressor and a condenser by absorbing a part of condenser waste heat. The results show that RSAC with HRWHS is adequate to generate hot water with the temperature range about 46.58˚C - 48.81˚C when compared to without HRWHS and the use of dummy condenser does not give significant effect to the split air conditioner performance. When the use of HRWHS, the refrigerant charge has increase about 19.05%, the compressor power consumption has slightly increase about 1.42% where cooling capacity almost the same with slightly different about 0.39%. The condenser heat rejection is lower about 2.68% and the COP has slightly increased about 1.05% when compared to without HRWHS. The use of HRWHS provide free hot water, it means there is energy saving for heating water without negative impact to the system performance of RSAC.

  7. Energy Savings and Breakeven Cost for Residential Heat Pump Water Heaters in the United States

    Energy Technology Data Exchange (ETDEWEB)

    Maguire, J.; Burch, J.; Merrigan, T.; Ong, S.

    2013-07-01

    Heat pump water heaters (HPWHs) have recently reemerged in the U.S. residential water heating market and have the potential to provide homeowners with significant energy savings. However, there are questions as to the actual performance and energy savings potential of these units, in particular in regards to the heat pump's performance in unconditioned space and the impact of the heat pump on space heating and cooling loads when it is located in conditioned space. To help answer these questions, simulations were performed of a HPWH in both conditioned and unconditioned space at over 900 locations across the continental United States and Hawaii. Simulations included a Building America benchmark home so that any interaction between the HPWH and the home's HVAC equipment could be captured. Comparisons were performed to typical gas and electric water heaters to determine the energy savings potential and cost effectiveness of a HPWH relative to these technologies. HPWHs were found to have a significant source energy savings potential when replacing typical electric water heaters, but only saved source energy relative to gas water heater in the most favorable installation locations in the southern US. When replacing an electric water heater, the HPWH is likely to break even in California, the southern US, and parts of the northeast in most situations. However, the HPWH will only break even when replacing a gas water heater in a few southern states.

  8. Energy Savings and Breakeven Costs for Residential Heat Pump Water Heaters in the United States

    Energy Technology Data Exchange (ETDEWEB)

    Maguire, Jeff [National Renewable Energy Lab. (NREL), Golden, CO (United States); Burch, Jay [National Renewable Energy Lab. (NREL), Golden, CO (United States); Merrigan, Tim [National Renewable Energy Lab. (NREL), Golden, CO (United States); Ong, Sean [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2013-07-01

    Heat pump water heaters (HPWHs) have recently re-emerged in the U.S. residential water heating market and have the potential to provide homeowners with significant energy savings. However, there are questions as to the actual performance and energy savings potential of these units, in particular in regards to the heat pump's performance in unconditioned space and the impact of the heat pump on space heating and cooling loads when it is located in conditioned space. To help answer these questions, NREL performed simulations of a HPWH in both conditioned and unconditioned space at over 900 locations across the continental United States and Hawaii. Simulations included a Building America benchmark home so that any interaction between the HPWH and the home's HVAC equipment could be captured. Comparisons were performed to typical gas and electric water heaters to determine the energy savings potential and cost effectiveness of a HPWH relative to these technologies. HPWHs were found to have a significant source energy savings potential when replacing typical electric water heaters, but only saved source energy relative to gas water heater in the most favorable installation locations in the southern United States. When replacing an electric water heater, the HPWH is likely to break even in California, the southern United States, and parts of the northeast in most situations. However, the HPWH will only break even when replacing a gas water heater in a few southern states.

  9. Expert Meeting Report: Recommendations for Applying Water Heaters in Combination Space and Domestic Water Heating Systems

    Energy Technology Data Exchange (ETDEWEB)

    Rudd, A.; Ueno, K.; Bergey, D.; Osser, R.

    2012-07-01

    The topic of this meeting was 'Recommendations For Applying Water Heaters In Combination Space And Domestic Water Heating Systems.' Presentations and discussions centered on the design, performance, and maintenance of these combination systems, with the goal of developing foundational information toward the development of a Building America Measure Guideline on this topic. The meeting was held at the Westford Regency Hotel, in Westford, Massachusetts on 7/31/2011.

  10. Building America Case Study: Addressing Multifamily Piping Losses with Solar Hot Water, Davis, California

    Energy Technology Data Exchange (ETDEWEB)

    2016-12-01

    Solar thermal water heating is most cost effective when applied to multifamily buildings and some states offer incentives or other inducements to install them. However, typical solar water heating designs do not allow the solar generated heat to be applied to recirculation losses, only to reduce the amount of gas or electric energy needed for hot water that is delivered to the fixtures. For good reasons, hot water that is recirculated through the building is returned to the water heater, not to the solar storage tank. The project described in this report investigated the effectiveness of using automatic valves to divert water that is normally returned through the recirculation piping to the gas or electric water heater instead to the solar storage tank. The valves can be controlled so that the flow is only diverted when the returning water is cooler than the water in the solar storage tank.

  11. Using Solar Hot Water to Address Piping Heat Losses in Multifamily Buildings

    Energy Technology Data Exchange (ETDEWEB)

    Springer, David [Alliance for Residential Building Innovation, Davis, CA (United States); Seitzler, Matt [Alliance for Residential Building Innovation, Davis, CA (United States); Backman, Christine [Alliance for Residential Building Innovation, Davis, CA (United States); Weitzel, Elizabeth [Alliance for Residential Building Innovation, Davis, CA (United States)

    2015-10-01

    Solar thermal water heating is most cost effective when applied to multifamily buildings and some states offer incentives or other inducements to install them. However, typical solar water heating designs do not allow the solar generated heat to be applied to recirculation losses, only to reduce the amount of gas or electric energy needed for hot water that is delivered to the fixtures. For good reasons, hot water that is recirculated through the building is returned to the water heater, not to the solar storage tank. The project described in this report investigated the effectiveness of using automatic valves to divert water that is normally returned through the recirculation piping to the gas or electric water heater instead to the solar storage tank. The valves can be controlled so that the flow is only diverted when the returning water is cooler than the water in the solar storage tank.

  12. Solar heating and domestic hot water system installed at Kansas City, Fire Stations, Kansas City, Missouri

    Science.gov (United States)

    1980-01-01

    The solar system was designed to provide 47 percent of the space heating, 8,800 square feet area and 75 percent of the domestic hot water (DHW) load. The solar system consists of 2,808 square feet of Solaron, model 2001, air, flat plate collector subsystem, a concrete box storage subsystem which contains 1,428 cubic feet of 0.5 inch diameter pebbles weighing 71.5 tons, a DHW preheat tank, blowers, pumps, heat exchangers, air ducting, controls and associated plumbing. Two 120 gallon electric DHW heaters supply domestic hot water which is preheated by the solar system. Auxiliary space heating is provided by three electric heat pumps with electric resistance heaters and four 30 kilowatt electric unit heaters. There are six modes of system operation.

  13. Solar heating and domestic hot water system installed at Kansas City, Fire Stations, Kansas City, Missouri

    Science.gov (United States)

    1980-07-01

    The solar system was designed to provide 47 percent of the space heating, 8,800 square feet area and 75 percent of the domestic hot water (DHW) load. The solar system consists of 2,808 square feet of Solaron, model 2001, air, flat plate collector subsystem, a concrete box storage subsystem which contains 1,428 cubic feet of 0.5 inch diameter pebbles weighing 71.5 tons, a DHW preheat tank, blowers, pumps, heat exchangers, air ducting, controls and associated plumbing. Two 120 gallon electric DHW heaters supply domestic hot water which is preheated by the solar system. Auxiliary space heating is provided by three electric heat pumps with electric resistance heaters and four 30 kilowatt electric unit heaters. There are six modes of system operation.

  14. Research and development of an air-cycle heat-pump water heater. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Dieckmann, J.T.; Erickson, A.J.; Harvey, A.C.; Toscano, W.M.

    1979-10-01

    A prototype reverse Brayton air cycle heat pump water heater has been designed and built for residential applications. The system consists of a compressor/expander, an air-water heat exchanger, an electric motor, a water circulation pump, a thermostat, and fluid management controls. The prototype development program consisted of a market analysis, design study, and development testing. A potential residential market for the new high-efficiency water heater of approximately 480,000 units/y was identified. The retail and installation cost of this water heater is estimated to be between $500 and $600 which is approximately $300 more than a conventional electric water heater. The average payback per unit is less than 3-1/2 y and the average recurring energy cost savings after the payback period is approximately $105/y at the average seasonal coefficient of performance (COP) of 1.7. As part of the design effort, a thermodynamic parametric analysis was performed on the water heater system. It was determined that to obtain a coefficient of performance of 1.7, the isentropic efficiency of both the compressor and the expander must be at least 85%. The selected mechanical configuration is described. The water heater has a diameter of 25 in. and a height of 73 in. The results of the development testing of the prototype water heater system showed: the electrical motor maximum efficiency of 78%; the compressor isentropic efficiency is 95 to 119% and the volumetric efficiency is approximately 85%; the expander isentropic efficiency is approximately 58% and the volumetric efficiency is 92%; a significant heat transfer loss of approximately 16% occurred in the expander; and the prototype heat pump system COP is 1.26 which is less than the design goal of at least 1.7. Future development work is recommended.

  15. Validation of a Hot Water Distribution Model Using Laboratory and Field Data

    Energy Technology Data Exchange (ETDEWEB)

    Backman, C.; Hoeschele, M.

    2013-07-01

    Characterizing the performance of hot water distribution systems is a critical step in developing best practice guidelines for the design and installation of high performance hot water systems. Developing and validating simulation models is critical to this effort, as well as collecting accurate input data to drive the models. In this project, the ARBI team validated the newly developed TRNSYS Type 604 pipe model against both detailed laboratory and field distribution system performance data. Validation efforts indicate that the model performs very well in handling different pipe materials, insulation cases, and varying hot water load conditions. Limitations of the model include the complexity of setting up the input file and long simulation run times. In addition to completing validation activities, this project looked at recent field hot water studies to better understand use patterns and potential behavioral changes as homeowners convert from conventional storage water heaters to gas tankless units. Based on these datasets, we conclude that the current Energy Factor test procedure overestimates typical use and underestimates the number of hot water draws. This has implications for both equipment and distribution system performance. Gas tankless water heaters were found to impact how people use hot water, but the data does not necessarily suggest an increase in usage. Further study in hot water usage and patterns is needed to better define these characteristics in different climates and home vintages.

  16. Validation of a Hot Water Distribution Model Using Laboratory and Field Data

    Energy Technology Data Exchange (ETDEWEB)

    Backman, C. [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States); Hoeschele, M. [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States)

    2013-07-01

    Characterizing the performance of hot water distribution systems is a critical step in developing best practice guidelines for the design and installation of high performance hot water systems. Developing and validating simulation models is critical to this effort, as well as collecting accurate input data to drive the models. In this project, the Building America research team ARBI validated the newly developed TRNSYS Type 604 pipe model against both detailed laboratory and field distribution system performance data. Validation efforts indicate that the model performs very well in handling different pipe materials, insulation cases, and varying hot water load conditions. Limitations of the model include the complexity of setting up the input file and long simulation run times. This project also looked at recent field hot water studies to better understand use patterns and potential behavioral changes as homeowners convert from conventional storage water heaters to gas tankless units. The team concluded that the current Energy Factor test procedure overestimates typical use and underestimates the number of hot water draws, which has implications for both equipment and distribution system performance. Gas tankless water heaters were found to impact how people use hot water, but the data does not necessarily suggest an increase in usage. Further study in hot water usage and patterns is needed to better define these characteristics in different climates and home vintages.

  17. Solar heating, cooling and domestic hot water system installed at Columbia Gas System Service Corp. , Columbus, Ohio. Final report

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-11-01

    The Solar Energy System located at the Columbia Gas Corporation, Columbus, Ohio, has 2978 ft/sup 2/ of Honeywell single axis tracking, concentrating collectors and provides solar energy for space heating, space cooling and domestic hot water. A 1,200,000 Btu/h Bryan water-tube gas boiler provides hot water for space heating. Space cooling is provided by a 100 ton Arkla hot water fired absorption chiller. Domestic hot water heating is provided by a 50 gallon natural gas domestic storage water heater. Extracts are included from the site files, specification references, drawings, installation, operation and maintenance instructions.

  18. Solar heating, cooling and domestic hot water system installed at Columbia Gas System Service Corporation, Columbus, Ohio

    Science.gov (United States)

    1980-01-01

    The solar energy system installed in the building has 2,978 sq ft of single axis tracking, concentrating collectors and provides solar energy for space heating, space cooling and domestic hot water. A 1,200,000 Btu/hour water tube gas boiler provides hot water for space heating. Space cooling is provided by a 100 ton hot water fired absorption chiller. Domestic hot water heating is provided by a 50 gallon natural gas domestic storage water heater. Extracts from the site files, specification references, drawings, installation, operation and maintenance instructions are included.

  19. OUT Success Stories: Solar Hot Water Technology

    Energy Technology Data Exchange (ETDEWEB)

    Clyne, R.

    2000-08-31

    Solar hot water technology was made great strides in the past two decades. Every home, commercial building, and industrial facility requires hot water. DOE has helped to develop reliable and durable solar hot water systems. For industrial applications, the growth potential lies in large-scale systems, using flat-plate and trough-type collectors. Flat-plate collectors are commonly used in residential hot water systems and can be integrated into the architectural design of the building.

  20. OUT Success Stories: Solar Hot Water Technology

    Science.gov (United States)

    Clyne, R.

    2000-08-01

    Solar hot water technology was made great strides in the past two decades. Every home, commercial building, and industrial facility requires hot water. DOE has helped to develop reliable and durable solar hot water systems. For industrial applications, the growth potential lies in large-scale systems, using flat-plate and trough-type collectors. Flat-plate collectors are commonly used in residential hot water systems and can be integrated into the architectural design of the building.

  1. Understanding the Ecological Adoption of Solar Water Heaters Among Customers of Island Economies

    Directory of Open Access Journals (Sweden)

    Pudaruth Sharmila

    2017-04-01

    Full Text Available This paper explores the major factors impacting upon the ecological adoption of solar water heaters in Mauritius. The paper applies data reduction technique by using exploratory factor analysis on a sample of 228 respondents and condenses a set of 32 attributes into a list of 8 comprehensible factors impacting upon the sustained adoption of solar water heater in Mauritius. Multiple regression analysis was also conducted to investigate upon the most predictive factor influencing the adoption of solar water heaters in Mauritius. The empirical estimates of the regression analysis have also depicted that the most determining factor pertaining to the ‘government incentives for solar water heaters’ impacts upon the adoption of solar water heaters. These results can be related to sustainable adoption of green energy whereby targeted incentive mechanisms can be formulated with the aim to accelerate and cascade solar energy adoption in emerging economies. A novel conceptual model was also proposed in this paper, whereby, ecological stakeholders in the sustainable arena could use the model as a reference to pave the way to encourage adoption of solar water heating energy. This research represents a different way of understanding ecological customers by developing an expanding on an original scale development for the survey on the ecological adoption of solar water heaters.

  2. An investigation of the Performance of a Conical Solar Water Heater in the Kingdom of Bahrain

    Directory of Open Access Journals (Sweden)

    Gaaliche Nessreen

    2017-01-01

    Full Text Available Domestic water heater corresponds to 25% of the house energy consumption and can play an important role to reduce energy house expenses. Solar energy offers a preferred renewable energy resource because of its economic and environmental advantages. It is considered the best alternative to reduce domestic water heater energy consumption cost. Converting solar energy into heat can be considered among the simplest used systems. Solar thermal conversion is more efficient than solar electrical direct conversion method. Solar water heater systems are particularly easy to use and to repair. The integrated conical solar collector water heater (ICSCWH is so far the easiest among water heating systems. The ICSCWH converts directly and efficiently the solar flux into heat. In order to expand the utilization of ICSCWH systems, many design modifications have been examined and analyzed. This study provides an experimental investigation and mathematical simulation of an ICSCWH system equipped with a glass cover resulting in the increase of the maximum absorption. Integrating the cone-shaped heat collector with an aluminum spiral pipe flow system may enhance the efficiency of the proposed system. In order to maximize the solar radiation of the system, the solar water heater has been designed in a conical shape, which removes the need to change its orientation toward the sun to receive the maximum sun radiation during the day. In this system, the heating of water has been obtained using the spiral pipe flow without the use of the solar cells and mirrors in order to reduce the total cost. The storage water tank of this system is coupled with a conical solar collector. Based on the above design, the solar water heater has been fabricated and tested. In addition, an analytical modeling approach aiming to predict the flow rate within the conical integrated collector storage solar water heater (ICSSWH and its efficiency, was developed. Modeling through a numerical

  3. An investigation of the Performance of a Conical Solar Water Heater in the Kingdom of Bahrain

    Science.gov (United States)

    Gaaliche, Nessreen; Ayhan, Teoman; Fathallah, Raouf

    2017-11-01

    Domestic water heater corresponds to 25% of the house energy consumption and can play an important role to reduce energy house expenses. Solar energy offers a preferred renewable energy resource because of its economic and environmental advantages. It is considered the best alternative to reduce domestic water heater energy consumption cost. Converting solar energy into heat can be considered among the simplest used systems. Solar thermal conversion is more efficient than solar electrical direct conversion method. Solar water heater systems are particularly easy to use and to repair. The integrated conical solar collector water heater (ICSCWH) is so far the easiest among water heating systems. The ICSCWH converts directly and efficiently the solar flux into heat. In order to expand the utilization of ICSCWH systems, many design modifications have been examined and analyzed. This study provides an experimental investigation and mathematical simulation of an ICSCWH system equipped with a glass cover resulting in the increase of the maximum absorption. Integrating the cone-shaped heat collector with an aluminum spiral pipe flow system may enhance the efficiency of the proposed system. In order to maximize the solar radiation of the system, the solar water heater has been designed in a conical shape, which removes the need to change its orientation toward the sun to receive the maximum sun radiation during the day. In this system, the heating of water has been obtained using the spiral pipe flow without the use of the solar cells and mirrors in order to reduce the total cost. The storage water tank of this system is coupled with a conical solar collector. Based on the above design, the solar water heater has been fabricated and tested. In addition, an analytical modeling approach aiming to predict the flow rate within the conical integrated collector storage solar water heater (ICSSWH) and its efficiency, was developed. Modeling through a numerical simulation approach

  4. Forced-circulation solar water heater using a solar battery; Taiyo denchi wo mochiita kyosei junkanshiki taiyonetsu onsuiki

    Energy Technology Data Exchange (ETDEWEB)

    Asai, S.; Mizuno, T. [Yazaki Resources Co. Ltd., Shizuoka (Japan)

    1996-10-27

    For the purpose of satisfying demands for qualitative improvement on tapwater temperature and pressure, an indirect-type solar water heater using solar cells, in which a closed type hot water storage tank connected directly to the water supply is integrated with a solar collector, was examined for its characteristics and performance. The heat collecting medium is a water solution of polypropylene glycol, which circulates through the solar collector pump, cistern, solar collector, and heat exchanger (hot water storage tank). The results of the test are summarized below. When comparison is made between the two solar collector pump control methods, the solar cells direct connection method and the differential thermo method utilizing temperature difference between the solar collector and the hot water storage tank, they are alike in collecting heat on clear days, but on cloudy days the latter collects 5% more than the former. In winter, when the heat exchanger heat transfer area is 0.4m{sup 2} large, a further increase in the area improves but a little the heat collecting efficiency. An increase in the medium flow rate and temperature, or in the Reynolds number, enhances the heat collecting efficiency. 13 figs., 6 tabs.

  5. Building America Case Study: Simple Retrofit High-Efficiency Natural Gas Water Heater Field Test, Minneapolis, Minnesota

    Energy Technology Data Exchange (ETDEWEB)

    T. Schirber, B. Schoenbauer

    2017-06-01

    High-performance water heaters are typically more time consuming and costly to install in retrofit applications, making high-performance water heaters difficult to justify economically. However, recent advancements in high-performance water heaters have targeted the retrofit market, simplifying installations and reducing costs. Four high-efficiency natural gas water heaters designed specifically for retrofit applications were installed in single-family homes along with detailed monitoring systems to characterize their savings potential, their installed efficiencies, and their ability to meet household demands.

  6. COMBINED UNCOVERED SHEET-AND-TUBE PVT-COLLECTOR SYSTEM WITH BUILT-IN STORAGE WATER HEATER

    Directory of Open Access Journals (Sweden)

    Muhammad Abid

    2012-02-01

    Full Text Available This work describes the design and investigation of a simple combined uncovered sheet-and-tube photo-voltaic-thermal (PVT collector system. The PVT-collector system consists of a support, standard PV module (1.22x0.305m, area=0.37m2, fill factor=0.75, sheet-and-tube water collector and storage tank-heater. The collector was fixed under PV module. Inclination angle of the PVT-collector to the horizontal plane was 45 degree. The storage tank-heater played double role i.e. for storage of hot water and for water heating. The PVT-collector system could work in the fixed and tracking modes of operation. During investigations of PVT-collector in natural conditions, solar irradiance, voltage and current of PV module, ambient temperature and water temperature in storage tank were measured. Average thermal and electrical powers of the PVT-collector system at the tracking mode of operation observed were 39W and 21W, with efficiencies of 15% and 8% respectively at the input power of 260W. The maximum temperature of the water obtained was 42oC. The system was observed efficient for low-temperature applications. The PVT-collector system may be used as a prototype for design of PVT-collector system for domestic application, teaching aid and for demonstration purposes.

  7. Building America Case Study: Assessment of a Hybrid Retrofit Gas Water Heater

    Energy Technology Data Exchange (ETDEWEB)

    M. Hoeschele, E. Weitzel, C. Backman

    2017-06-01

    This project completed a modeling evaluation of a hybrid gas water heater that combines a reduced capacity tankless unit with a downsized storage tank. This product would meet a significant market need by providing a higher efficiency gas water heater solution for retrofit applications while maintaining compatibility with the half-inch gas lines and standard B vents found in most homes. The TRNSYS simulation tool was used to model a base case 0.60 EF atmospheric gas storage water, a 0.82 EF non-condensing gas tankless water heater, an existing (high capacity) hybrid unit on the market, and an alternative hybrid unit with lower storage volume and reduced gas input requirements.

  8. Economics of Hot Water Dipping

    OpenAIRE

    P., Maxin; K., Klopp

    2004-01-01

    Hot water dipping is an appropriate method to protect apples against spoilage caused by gloeosporium rot. Tests on the varieties Topaz and Ingrid Marie at the OVB Jork (Germany) have demonstrated an effective reduction of spoilage from between 80% and 92% in charges by an infection rate of 40%. The result of an intensive R&D process between 2002 and 2003 is the development of a praxis-tested big box (300 kg) dipping station. With the first Bio Dipping systems now on the mark...

  9. Technical support document: Energy efficiency standards for consumer products: Room air conditioners, water heaters, direct heating equipment, mobile home furnaces, kitchen ranges and ovens, pool heaters, fluorescent lamp ballasts and television sets. Volume 3, Water heaters, pool heaters, direct heating equipment, and mobile home furnaces

    Energy Technology Data Exchange (ETDEWEB)

    1993-11-01

    This is Volume 3 in a series of documents on energy efficiency of consumer products. This volume discusses energy efficiency of water heaters. Water heaters are defined by NAECA as products that utilize oil, gas, or electricity to heat potable water for use outside the heater upon demand. These are major appliances, which use a large portion (18% on average) of total energy consumed per household (1). They differ from most other appliances in that they are usually installed in obscure locations as part of the plumbing and are ignored until they fail. Residential water heaters are capable of heating water up to 180{degrees}F, although the setpoints are usually set lower.

  10. 16 CFR Appendix D1 to Part 305 - Water Heaters-Gas

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Water Heaters-Gas D1 Appendix D1 to Part 305... Part 305—Water Heaters—Gas Range Information CAPACITY FIRST HOUR RATING Range of Estimated Annual Operating Costs (Dollars/Year) Natural Gas ($/year) Low High Propane ($/year) Low High Less than 21...

  11. 16 CFR Appendix D5 to Part 305 - Water Heaters-Heat Pump

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Water Heaters-Heat Pump D5 Appendix D5 to Part 305 Commercial Practices FEDERAL TRADE COMMISSION REGULATIONS UNDER SPECIFIC ACTS OF CONGRESS RULE... Appendix D5 to Part 305—Water Heaters—Heat Pump Range Information CAPACITY FIRST HOUR RATING Range of...

  12. 16 CFR Appendix D2 to Part 305 - Water Heaters-Electric

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Water Heaters-Electric D2 Appendix D2 to... PRODUCTS REQUIRED UNDER THE ENERGY POLICY AND CONSERVATION ACT (âAPPLIANCE LABELING RULEâ) Pt. 305, App. D2 Appendix D2 to Part 305—Water Heaters—Electric Range Information CAPACITY FIRST HOUR RATING Range of...

  13. Technology Learning Activities. Design Brief--Measuring Inaccessible Distances. Alternative Energy Sources: Designing a Wind Powered Generator. Alternative Energy Sources: Designing a Hot Dog Heater Using Solar Energy.

    Science.gov (United States)

    Technology Teacher, 1991

    1991-01-01

    These three learning activities are on measuring accessible distances, designing a wind powered generator, and designing a hot dog heater using solar energy. Each activity includes description of context, objectives, list of materials and equipment, challenge to students, and evaluation questions. (SK)

  14. Feed-water heaters alternative design comparison; Comparacion de disenos alternativos de calentadores

    Energy Technology Data Exchange (ETDEWEB)

    Torres Toledano, Gerardo [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1988-12-31

    A procedure is presented for the alternative design comparison of feed water heaters, based in the failure records of damaged tubes during operation. The procedure is used for cases in which non-continuous or random inspections are made to the feed-water heaters. [Espanol] Se presenta un procedimiento para comparar disenos alternativos de calentadores, basandose en los registros de fallas de los tubos rotos acumuladas durante su operacion. El procedimiento se emplea para casos en los que se realizan inspecciones a los calentadores no continuas, ya sea periodicas o al azar.

  15. Building America Case Study: Simple Retrofit High-Efficiency Natural Gas Water Heater Field Test, Minneapolis, Minnesota

    Energy Technology Data Exchange (ETDEWEB)

    2017-06-12

    High performance water heaters are typically more time consuming and costly to install in retrofit applications, making high performance water heaters difficult to justify economically. However, recent advancements in high performance water heaters have targeted the retrofit market, simplifying installations and reducing costs. Four high efficiency natural gas water heaters designed specifically for retrofit applications were installed in single-family homes along with detailed monitoring systems to characterize their savings potential, their installed efficiencies, and their ability to meet household demands. The water heaters tested for this project were designed to improve the cost-effectiveness and increase market penetration of high efficiency water heaters in the residential retrofit market. The retrofit high efficiency water heaters achieved their goal of reducing costs, maintaining savings potential and installed efficiency of other high efficiency water heaters, and meeting the necessary capacity in order to improve cost-effectiveness. However, the improvements were not sufficient to achieve simple paybacks of less than ten years for the incremental cost compared to a minimum efficiency heater. Significant changes would be necessary to reduce the simple payback to six years or less. Annual energy savings in the range of $200 would also reduce paybacks to less than six years. These energy savings would require either significantly higher fuel costs (greater than $1.50 per therm) or very high usage (around 120 gallons per day). For current incremental costs, the water heater efficiency would need to be similar to that of a heat pump water heater to deliver a six year payback.

  16. Performance Monitoring of Residential Hot Water Distribution Systems

    Energy Technology Data Exchange (ETDEWEB)

    Liao, Anna; Lanzisera, Steven; Lutz, Jim; Fitting, Christian; Kloss, Margarita; Stiles, Christopher

    2014-08-11

    Current water distribution systems are designed such that users need to run the water for some time to achieve the desired temperature, wasting energy and water in the process. We developed a wireless sensor network for large-scale, long time-series monitoring of residential water end use. Our system consists of flow meters connected to wireless motes transmitting data to a central manager mote, which in turn posts data to our server via the internet. This project also demonstrates a reliable and flexible data collection system that could be configured for various other forms of end use metering in buildings. The purpose of this study was to determine water and energy use and waste in hot water distribution systems in California residences. We installed meters at every end use point and the water heater in 20 homes and collected 1s flow and temperature data over an 8 month period. For a typical shower and dishwasher events, approximately half the energy is wasted. This relatively low efficiency highlights the importance of further examining the energy and water waste in hot water distribution systems.

  17. To investigate the surface properties for increasing efficiency of solar water heater

    Science.gov (United States)

    Hai, A.; Qurat-ul-Ain

    2013-06-01

    Energy crisis is becoming a major problem in Pakistan. Renewable energy sources are used to overcome this crisis. This research is about to increase the efficiency of fin type solar water heater by modification of its surface properties. During this research work, solar water heater module is fabricated and the modification of surfaces by using bare surface, external surface coated with high conductivity paint and lead electroplating is studied and the efficiency of solar heater is observed. The temperature profile and the heat transferred is studied and it was found that paint coated surface is more efficient than bare surface, further surface electroplated with lead is more efficient than painted surface for the same ambient conditions. The average increase in the heat absorption for lead plated and paint coated surface was observed 28.57% and 10.79 % respectively.

  18. Heat Pump Water Heater Technology: Experiences of Residential Consumers and Utilities

    Energy Technology Data Exchange (ETDEWEB)

    Ashdown, BG

    2004-08-04

    This paper presents a case study of the residential heat pump water heater (HPWH) market. Its principal purpose is to evaluate the extent to which the HPWH will penetrate the residential market sector, given current market trends, producer and consumer attributes, and technical parameters. The report's secondary purpose is to gather background information leading to a generic framework for conducting market analyses of technologies. This framework can be used to compare readiness and to factor attributes of market demand back into product design. This study is a rapid prototype analysis rather than a detailed case analysis. For this reason, primary data collection was limited and reliance on secondary sources was extensive. Despite having met its technical goals and having been on the market for twenty years, the HPWH has had virtually no impact on contributing to the nation's water heating. In some cases, HPWH reliability and quality control are well below market expectations, and early units developed a reputation for unreliability, especially when measured against conventional water heaters. In addition to reliability problems, first costs of HPWH units can be three to five times higher than conventional units. Without a solid, well-managed business plan, most consumers will not be drawn to this product. This is unfortunate. Despite its higher first costs, efficiency of an HPWH is double that of a conventional water heater. The HPWH also offers an attractive payback period of two to five years, depending on hot water usage. On a strict life-cycle basis it supplies hot water very cost effectively. Water heating accounts for 17% of the nation's residential consumption of electricity (see chart at left)--water heating is second only to space heating in total residential energy use. Simple arithmetic suggests that this figure could be reduced to the extent HPWH technology displaces conventional water heating. In addition, the HPWH offers other

  19. Performance improvements in commercial heat pump water heaters using carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Bowers, C. D.; Elbel, S.; Petersen, M.; Hrnjak, P. S.

    2011-09-15

    Although heat pump water heaters are today widely accepted in Japan, where energy costs are high and government incentives for their use exist, acceptance of such a product in the U.S. has been slow. This trend is slowly changing with the introduction of heat pump water heaters into the residential market, but remains in the commercial sector. Barriers to heat pump water heater acceptance in the commercial market have historically been performance, reliability and first/operating costs. The use of carbon dioxide (R744) as the refrigerant in such a system can improve performance for relatively small increase in initial cost and make this technology more appealing. What makes R744 an excellent candidate for use in heat pump water heaters is not only the wide range of ambient temperatures within which it can operate, but also the excellent ability to match water to refrigerant temperatures on the high side, resulting in very high exit water temperatures of up to 82ºC (180ºF), as required by sanitary codes in the U.S.(Food Code, 2005), in a single pass, temperatures that are much more difficult to reach with other refrigerants. This can be especially attractive in applications where this water is used for the purpose of sanitation. While reliability has also been of concern historically, dramatic improvements have been made over the last several years through research done in the automotive industry and commercialization of R744 technology in residential water heating mainly in Japan. This paper presents the performance results from the development of an R744 commercial heat pump water heater of approximately 35kW and a comparison to a baseline R134a unit of the same capacity and footprint. In addition, recommendations are made for further improvements of the R744 system which could result in possible energy savings of up to 20%.

  20. Forecasting HotWater Consumption in Residential Houses

    Directory of Open Access Journals (Sweden)

    Linas Gelažanskas

    2015-11-01

    Full Text Available An increased number of intermittent renewables poses a threat to the system balance. As a result, new tools and concepts, like advanced demand-side management and smart grid technologies, are required for the demand to meet supply. There is a need for higher consumer awareness and automatic response to a shortage or surplus of electricity. The distributed water heater can be considered as one of the most energy-intensive devices, where its energy demand is shiftable in time without influencing the comfort level. Tailored hot water usage predictions and advanced control techniques could enable these devices to supply ancillary energy balancing services. The paper analyses a set of hot water consumption data from residential dwellings. This work is an important foundation for the development of a demand-side management strategy based on hot water consumption forecasting at the level of individual residential houses. Various forecasting models, such as exponential smoothing, seasonal autoregressive integrated moving average, seasonal decomposition and a combination of them, are fitted to test different prediction techniques. These models outperform the chosen benchmark models (mean, naive and seasonal naive and show better performance measure values. The results suggest that seasonal decomposition of the time series plays the most significant part in the accuracy of forecasting.

  1. Washing Habits and Machine with Intake of hot and cold Water

    DEFF Research Database (Denmark)

    Christensen, Bente Lis; Nørgaard, Jørgen

    1997-01-01

    with slightly adapted washing habits, or 17% of normal today. If the heat is supplied from combined heat and power production as in the actual experiment, CO2-emission is reduced by 81%. With hot water from oil or gas heaters the reduction will be slightly lower, while with solar hot water it will be larger.......Domestic washing machines typically spend around 80% of the electricity on heating water. Most of this can be replaced by more appropriate heat sources like district heat from combined heat and power production, or gas heating system. In recent years some washing machine manufacturers have marketed...... machines which can take in both hot and cold water and mix it to the temperature wanted. Such one machine has been tested in daily household use over 5 months, with habits of very few hot water washes. The result is an electricity consumption corresponding to 67 kWh per year for an average household...

  2. Local Adaptive Control of Solar Photovoltaics and Electric Water Heaters for Real-time Grid Support

    DEFF Research Database (Denmark)

    Bhattarai, Bishnu Prasad; Mendaza, Iker Diaz de Cerio; Bak-Jensen, Birgitte

    2016-01-01

    , such as electric vehicles, electric water heaters (EWHs) etc. An adaptive control using only local measurements for the EWHs and PVs is proposed in this study to alleviate OV as well as UV issues. The adaptive control is designed such that it monitors the voltage at the point of connection and adjusts active...

  3. Development of High Efficiency Carbon Dioxide Commercial Heat Pump Water Heater

    Energy Technology Data Exchange (ETDEWEB)

    Michael PETERSEN; Chad D. BOWERS; Stefan ELBEL; Pega HRNJAK

    2012-07-01

    Although heat pump water heaters are today widely accepted in both Japan and Europe, where energy costs are high and government incentives for their use exist, acceptance of such products in the US has been limited. While this trend is slowly changing with the introduction of heat pump water heaters into the residential market, but acceptance remains low in the commercial sector. The objective of the presented work is the development of a high efficiency R744 heat pump water heater for commercial applications with effective utilization of the cooling capability for air conditioning and/or refrigeration. The ultimate goal is to achieve total system COP of up to 8. This unit will be targeted at commercial use where some cooling load is typically needed year round, such as restaurants, hotels, nursing homes, and hospitals. This paper presents the performance results from the development of four R744 commercial heat pump water heater packages of approximately 35 kW and comparison to a commercially available baseline R134a unit of the same capacity and footprint. In addition, the influences of an internal heat exchanger and an enhanced evaporator on the system performance are described and recommendations are made for further improvements of the R744 system.

  4. Acceptability of the integral solar water heater by householders in the low income urban community

    CSIR Research Space (South Africa)

    Basson, FA

    1984-01-01

    Full Text Available A research and demonstration project on the use and performance of low cost integral solar water heaters in urban low-income dwellings was carried out in 1982/83. The project involved technical and socio-economic components. This report summarises...

  5. A figure of merit for selective absorbers in flat plate solar water heaters

    CSIR Research Space (South Africa)

    Roberts, DE

    2013-12-01

    Full Text Available We derive from first principles an analytical expression for a figure of merit (FM) for a selective solar absorber in a single glazed flat plate water heater. We first show that the efficiency of a collector with an absorber with absorptance α...

  6. Measure Guideline. Heat Pump Water Heaters in New and Existing Homes

    Energy Technology Data Exchange (ETDEWEB)

    Shapiro, Carl [Consortium for Advanced Residential Buildings (CARB), Norwalk, CT (United States); Puttagunta, Srikanth [Consortium for Advanced Residential Buildings (CARB), Norwalk, CT (United States); Owens, Douglas [Consortium for Advanced Residential Buildings (CARB), Norwalk, CT (United States)

    2012-02-01

    This Building America Measure Guideline is intended for builders, contractors, homeowners, and policy-makers. This document is intended to explore the issues surrounding heat pump water heaters (HPWHs) to ensure that homeowners and contractors have the tools needed to appropriately and efficiently install HPWHs

  7. Experimental Investigation of a Natural Circulation Solar Domestic Water Heater Performance under Standard Consumption Rate

    DEFF Research Database (Denmark)

    Kolaei, Alireza Rezania; Taherian, H.; Ganji, D. D.

    2012-01-01

    This paper reports experimental studies on the performance of a natural circulation solar water heater considering the weather condition of a city in north of Iran. The tests are done on clear and partly cloudy days. The variations of storage tank temperature due to consumption from the tank, dai...

  8. ON A NEW TECHNOLOGY OF PREPARATION OF HOT DRINKING WATER

    Directory of Open Access Journals (Sweden)

    M. F. Jalilov

    2017-01-01

    Full Text Available The present article contains information concerning the new Cl-anionization technology in the preparation of hot drinking water. In contrast with water softening, that replaces all the hardness salts by sodium cations in the cation exchanger, this new technology makes it possible to replace incrustating HCO3̄ and SO42--anions in a strong-base anion exchanger by Cl⁻-ions. As a result, the incrustation on the surfaces of heating hot water heaters is prevented. Thus, cations of hardness that are valuable for the human body remain in the water, the quality of the latter conforming to drinking water quality. Considering the important role of calcium and magnesium in the human body, in Germany and Turkey the minimum value of hardness cations in drinking water is limited to 2.85 and 7.50 mg-Eqv/l, respectively. According to the World Health Organization, in the composition of drinking water, the concentration of cations of magnesium and calcium is recommended, respectively, within 10–(20–30, and 20–50 mg/l; the minimum value of total hardness is 2–4 mg-Eqv/l. According to the developed technology drinking water is passed consistently in the downward direction through the mechanical and chlorineanionite exchanger filters. In the latter, the main part of HCO3̄ and SO42--water ions are exchanged for Cl-anions of anionite. Then the water is collected in the tank, from where it is pumped to the hot water heater through the ultraviolet disinfection unit. After the depletion of the anionite by HCO3̄ and SO42--anions, it is regenerated by a solution of 8–12 % NaCl. The results of research by the anion exchangers Purolite A200EMBCl and AB-17-8 are plotted. It is noted that when the specific consumption of salt for regeneration is of about 45–55 kg/m³, working exchange capacity of the A200EMBCl occurs to be in the range 300–370 g-Eqv/m³. For anionization of water, the residual concentration of HCO3̄-ions are changed from 0.5 to 3.2 mg

  9. Uncoverd-collector, solar water heater for swimming pool showers. Impianti solari con collettori scoperti per produzione stagionale di acqua calda in stabilimenti balneari

    Energy Technology Data Exchange (ETDEWEB)

    Bertocchi, A.; Caselli, G.; Maccari, A.

    1990-01-01

    The solar water heater, designed for use in climates such as that found on the Adriatic coastline, makes use of a single, or direct pass system (thus eliminating any need for storage tanks and thermostatic valves) to satisfy typical requirements such as 2,000 liters/day of 24-27 degrees C minimum/35 degrees maximum hot water for showers. This supply can be met by a 6.3 square meter, polypropylene collector surface area to heat 15 degree, network fed water. The basis of the system's design and its main performance characteristics, simulated and prototype, are outlined in this paper.

  10. Effect of contact-type feedwater heaters on the water-chemistry of power-generating units

    Energy Technology Data Exchange (ETDEWEB)

    Permyakov, V.A.; Kuskov, I.A.; Efimochkin, G.I.; Ermolov, V.F.; Trifonov, N.N.; Taran, E.E.; Sokolov, B.M.; Gerasimov, V.V.

    1986-09-01

    Discusses the advantages of contact-type feedwater heaters, which include elimination of subcooling, improved reliability, and better feedwater quality. Details a number of designs of these heaters. Concludes that the use of these heaters is advisable with any water-chemistry conditions; stability of the required oxygen concentration in the feedheater is assured with venting of the steam volume of the deaerator and automatic dosing of oxygen at the inlet to the booster pumps; and that technical measures have been developed and applied which enable condensate to be thoroughly deaerated in contact-type low pressure heaters. 7 refs.

  11. DEVELOPMENT AND PRELIMINARY TESTING OF A PARABOLIC TROUGH SOLAR WATER HEATER

    Directory of Open Access Journals (Sweden)

    O. A. Lasode

    2011-06-01

    Full Text Available Solar energy is a high-temperature, high-energy radiant energy source, with tremendous advantages over other alternative energy sources. It is a reliable, robust renewable resource which is largely undeveloped. The design and fabrication of parabolic trough solar water heater for water heating was executed. The procedure employed includes the design, construction and testing stages. The equipment which is made up of the reflector surface (curved mirror, reflector support, absorber pipe and a stand was fabricated using locally sourced materials. The results obtained. compared favourably with other research works in the literature. It depicts that employing a suitable design, selection of time of heating and proper focusing of the reflected rays to the focal spot region, solar radiation can efficiently be utilized for water heating in a tropical environment. This work presents a parabolic trough solar water heater as a suitable renewable energy technology for reducing water-heating costs.

  12. Solar Energy for Space Heating & Hot Water.

    Science.gov (United States)

    Energy Research and Development Administration, Washington, DC. Div. of Solar Energy.

    This pamphlet reviews the direct transfer of solar energy into heat, particularly for the purpose of providing space and hot water heating needs. Owners of buildings and homes are provided with a basic understanding of solar heating and hot water systems: what they are, how they perform, the energy savings possible, and the cost factors involved.…

  13. Basics of Solar Heating & Hot Water Systems.

    Science.gov (United States)

    American Inst. of Architects, Washington, DC.

    In presenting the basics of solar heating and hot water systems, this publication is organized from the general to the specific. It begins by presenting functional and operational descriptions of solar heating and domestic hot water systems, outlining the basic concepts and terminology. This is followed by a description of solar energy utilization…

  14. Effect of Installation of Solar Collector on Performance of Balcony Split Type Solar Water Heaters

    Directory of Open Access Journals (Sweden)

    Xu Ji

    2015-01-01

    Full Text Available The influences of surface orientation and slope of solar collectors on solar radiation collection of balcony split type solar water heaters for six cities in China were analyzed by employing software TRNSYS. The surface azimuth had greater effect on solar radiation collection in high latitude regions. For deviation of the surface slope angle within ±20° around the optimized angle, the variation of the total annual collecting solar radiation was less than 5%. However, with deviation of 70° to 90°, the variation was up to 20%. The effects of water cycle mode, reverse slope placement of solar collector, and water tank installation height on system efficiency were experimentally studied. The thermal efficiencies of solar water heater with single row horizontal arrangement all-glass evacuated tubular collector were higher than those with vertical arrangement at the fixed surface slope angle of 90°. Compared with solar water heaters with flat-plate collector under natural circulation, the system thermal efficiency was raised up to 63% under forced circulation. For collector at reverse slope placement, the temperature-based water stratification in water tank deteriorated, and thus the thermal efficiency became low. For improving the system efficiency, an appropriate installation height of the water tank was suggested.

  15. Biofilm formation in a hot water system

    DEFF Research Database (Denmark)

    Bagh, L.K.; Albrechtsen, Hans-Jørgen; Arvin, Erik

    2002-01-01

    The biofilm formation rate was measured in situ in a hot water system in an apartment building by specially designed sampling equipment, and the net growth of the suspended bacteria was measured by incubation of water samples with the indigeneous bacteria. The biofilm formation rate reached......, in the sludge, or in the water from the distribution system was negligible. This indicated that bacterial growth took place on the inner surfaces in the hot water system and biofilm formation and detachment of bacteria could account for most of the suspended bacteria actually measured in hot water. Therefore...

  16. Experimental study on a prototype solar water heater using refrigerant R141b as a transfer fluid

    Science.gov (United States)

    Ambarita, Himsar; Sitepu, Tekad

    2017-09-01

    A prototype of a heat pipe type solar water heater by using refrigerant as a heat transfer fluid is investigated experimentally. The objective is to explore the performance and characteristics of the prototype when it is filled with R141b. A prototype of the solar water heater with flat plate collector is designed and fabricated. In the experiments, two different refrigerants, R141b and R718, are employed, respectively. The initial pressure of transfer fluid is varied from 10 psi to 55 psi. The prototype is exposed to solar irradiation in a location in Medan city. Solar collector temperatures, solar irradiation, water temperature, and ambient temperature are measured. The efficiency of the system is analyzed. The results show that at the same initial pressure, the solar water heater filled with R141b is better than R718. The optimum initial pressure of the solar water heater filled with R141b is 30 psi. Thermal efficiency of the solar water heater at pressure 30 psi can be up to 34%. The main conclusion can be drawn here is that the solar water heater using refrigerant R141b as a transfer fluid results in a better performance in comparison with conventional water heater.

  17. Temperature distributions in trapezoidal built in storage solar water heaters with/without phase change materials

    Energy Technology Data Exchange (ETDEWEB)

    Tarhan, Sefa; Yardim, M. Hakan [Department of Farm Machinery, Faculty of Agriculture, Gaziosmanpasa University, Tasliciftlik Yerleskesi, 60240 Tokat (Turkey); Sari, Ahmet [Department of Chemistry, Faculty of Arts and Sciences, Gaziosmanpasa University, Tasliciftlik Yerleskesi, 60240 Tokat (Turkey)

    2006-09-15

    Built in storage solar water heaters (BSSWHs) have been recognized for their more compact constructions and faster solar gain than conventional solar water heaters, however, their water temperatures quickly go down during the cooling period. A trapezoidal BSSWH without PCM storage unit was used as the control heater (reference) to investigate the effect of two differently configured PCM storage units on the temperature distributions in water tanks. In the first design, myristic acid was filled into the PCM storage tank, which also served as an absorbing plate. In the second design, lauric acid was filled into the PCM storage tank, which also served as a baffle plate. The water temperature changes were followed by five thermocouples placed evenly and longitudinally into each of the three BSSWHs. The effects of the PCMs on the water temperature distributions depended on the configuration of the PCM storage unit and the longitudinal position in the water tanks. The use of lauric acid lowered the values of the peak temperatures by 15% compared to the control heater at the upper portion of the water tanks because of the low melting temperature of lauric acid, but it did not have any consistent effect on the retention of the water temperatures during the cooling period. The ability of the myristic acid storage unit to retain the water temperatures got more remarkable, especially at the middle portion of the water tank. The myristic acid storage increased the dip temperatures by approximately 8.8% compared to the control heater. In conclusion, lauric acid storage can be used to stabilize the water temperature during the day time, while the myristic acid storage unit can be used as a thermal barrier against heat loss during the night time because of its relatively high melting temperature and low heat conduction coefficient in its solid phase. The experimental results have also indicated that the thermal characteristics of the PCM and the configuration of the PCM storage

  18. Energy Efficiency Modelling of Residential Air Source Heat Pump Water Heater

    Directory of Open Access Journals (Sweden)

    Cong Toan Tran

    2016-03-01

    Full Text Available The heat pump water heater is one of the most energy efficient technologies for heating water for household use. The present work proposes a simplified model of coefficient of performance and examines its predictive capability. The model is based on polynomial functions where the variables are temperatures and the coefficients are derived from the Australian standard test data, using regression technics. The model enables to estimate the coefficient of performance of the same heat pump water heater under other test standards (i.e. US, Japanese, European and Korean standards. The resulting estimations over a heat-up phase and a full test cycle including a draw off pattern are in close agreement with the measured data. Thus the model allows manufacturers to avoid the need to carry out physical tests for some standards and to reduce product cost. The limitations of the methodology proposed are also discussed.

  19. Heat Pump Water Heaters: Controlled Field Research of Impact on Space Conditioning and Demand Response Characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Parker, Graham B.; Widder, Sarah H.; Eklund, Ken; Petersen, Joseph M.; Sullivan, Greg

    2015-10-05

    A new generation of heat pump water heaters (HPWH) has been introduced into the U.S. market that promises to provide significant energy savings for water heating. Many electric utilities are promoting their widespread adoption as a key technology for meeting energy conservation goals and reducing greenhouse gas emissions. There is, however, considerable uncertainty regarding the space conditioning impact of an HPWH installed in a conditioned space. There is also uncertainty regarding the potential for deployment of HPWHs in demand response (DR) programs to help manage and balance peak utility loads in a similar manner as conventional electric resistance water heaters (ERWH). To help answer these uncertainties, controlled experiments have been undertaken over 30 months in a matched pair of unoccupied Lab Homes located on the campus of the Pacific Northwest National Laboratory (PNNL) in Richland, Washington.

  20. A high turndown, ultra low emission low swirl burner for natural gas, on-demand water heaters

    Energy Technology Data Exchange (ETDEWEB)

    Rapp, Vi H. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Cheng, Robert K. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Therkelsen, Peter L. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2017-06-13

    Previous research has shown that on-demand water heaters are, on average, approximately 37% more efficient than storage water heaters. However, approximately 98% of water heaters in the U.S. use storage water heaters while the remaining 2% are on-demand. A major market barrier to deployment of on-demand water heaters is their high retail cost, which is due in part to their reliance on multi-stage burner banks that require complex electronic controls. This project aims to research and develop a cost-effective, efficient, ultra-low emission burner for next generation natural gas on-demand water heaters in residential and commercial buildings. To meet these requirements, researchers at the Lawrence Berkeley National Laboratory (LBNL) are adapting and testing the low-swirl burner (LSB) technology for commercially available on-demand water heaters. In this report, a low-swirl burner is researched, developed, and evaluated to meet targeted on-demand water heater performance metrics. Performance metrics for a new LSB design are identified by characterizing performance of current on-demand water heaters using published literature and technical specifications, and through experimental evaluations that measure fuel consumption and emissions output over a range of operating conditions. Next, target metrics and design criteria for the LSB are used to create six 3D printed prototypes for preliminary investigations. Prototype designs that proved the most promising were fabricated out of metal and tested further to evaluate the LSB’s full performance potential. After conducting a full performance evaluation on two designs, we found that one LSB design is capable of meeting or exceeding almost all the target performance metrics for on-demand water heaters. Specifically, this LSB demonstrated flame stability when operating from 4.07 kBTU/hr up to 204 kBTU/hr (50:1 turndown), compliance with SCAQMD Rule 1146.2 (14 ng/J or 20 ppm NOX @ 3% O2), and lower CO emissions than state

  1. Impact on Water Heater Performance of Heating Methods that Promote Tank Temperature Stratification

    Energy Technology Data Exchange (ETDEWEB)

    Gluesenkamp, Kyle R [ORNL; BushPE, John D [Electric Power Research Institute (EPRI)

    2016-01-01

    During heating of a water heater tank, the vertical temperature stratification of the water can be increased or decreased, depending on the method of heating. Methods that increase stratification during heating include (1) removing cold water from the tank bottom, heating it, and re-introducing it to the tank top at relatively low flow rate, (2) using a heat exchanger wrapped around the tank, through which heating fluid (with finite specific heat) flows from top to bottom, and (3) using an immersed heat element that is relatively high in the tank. Using such methods allows for improved heat pump water heater (HPWH) cycle efficiencies when the heat pump can take advantage of the lower temperatures that exist lower in the tank, and accommodate the resulting glide. Transcritical cycles are especially well-suited to capitalize on this opportunity, and other HPWH configurations (that have been proposed elsewhere) may benefit as well. This work provides several stratification categories of heat pump water heater tank configurations relevant to their stratification potential. To illustrate key differences among categories, it also compiles available experimental data for (a) single pass pumped flow, (b) multi-pass pumped flow, and (c) top-down wrapped tank with transcritical refrigerant.

  2. Application of a Linear Input/Output Model to Tankless Water Heaters

    Energy Technology Data Exchange (ETDEWEB)

    Butcher T.; Schoenbauer, B.

    2011-12-31

    In this study, the applicability of a linear input/output model to gas-fired, tankless water heaters has been evaluated. This simple model assumes that the relationship between input and output, averaged over both active draw and idle periods, is linear. This approach is being applied to boilers in other studies and offers the potential to make a small number of simple measurements to obtain the model parameters. These parameters can then be used to predict performance under complex load patterns. Both condensing and non-condensing water heaters have been tested under a very wide range of load conditions. It is shown that this approach can be used to reproduce performance metrics, such as the energy factor, and can be used to evaluate the impacts of alternative draw patterns and conditions.

  3. Assessment of the environmental impacts deriving from the life cycle of a typical solar water heater

    Directory of Open Access Journals (Sweden)

    G. Gaidajis

    2014-01-01

    Full Text Available According to life cycle thinking, the environmental burden deriving from different life cycle stages of a product or a system, such as manufacturing, transportation, maintenance and landfilling should be taken into consideration while assessing its environmental performance. In that aspect, the environmental impacts deriving from the life cycle of a typical solar water heater (SWH in Greece are analyzed and assessed with the application of relative life cycle assessment (LCA software in this study. In order to examine various impact categories such as global warming, ozone layer depletion, ecotoxicity and so forth, the IMPACT2002+ method is applied. The aim of this study is to examine the life cycle stages, processes and materials that significantly affect the system under examination and to provide a discussion regarding the environmental friendliness of solar water heaters.

  4. Guidebook for the Development of a Nationally Appropriate Mitigation Action for Solar Water Heaters

    DEFF Research Database (Denmark)

    Haselip, James Arthur; Lütken, Søren E.; Sharma, Sudhir

    This guidebook provides an introduction to designing government-led interventions to scale up investment in solar water heater (SWH) markets, showing how these interventions can be packaged as Nationally Appropriate Mitigation Actions (NAMAS). Reflecting the changing balance in global greenhouse...... gas emissions, NAMAs embody the principle of common but differentiated responsibilities. In addition to developed countries’ commitments to make quantitative reductions of greenhouse gas emissions, developing countries are invited to contribute with voluntary actions that are ‘nationally appropriate...

  5. an automatic safety control for immersion water heater

    African Journals Online (AJOL)

    NIJOTECH

    The resistance decreases) as the temperature is increased as well as when the water contains more impurities. Due to the proximity of the probe wires to the ac supply lines it was observed during measurement that ac noise became super imposed on the probe signals. The diode D1 was thus added to rectify any ac signals.

  6. Refrigerant charge management in a heat pump water heater

    Science.gov (United States)

    Chen, Jie; Hampton, Justin W.

    2014-06-24

    Heat pumps that heat or cool a space and that also heat water, refrigerant management systems for such heat pumps, methods of managing refrigerant charge, and methods for heating and cooling a space and heating water. Various embodiments deliver refrigerant gas to a heat exchanger that is not needed for transferring heat, drive liquid refrigerant out of that heat exchanger, isolate that heat exchanger against additional refrigerant flowing into it, and operate the heat pump while the heat exchanger is isolated. The heat exchanger can be isolated by closing an electronic expansion valve, actuating a refrigerant management valve, or both. Refrigerant charge can be controlled or adjusted by controlling how much liquid refrigerant is driven from the heat exchanger, by letting refrigerant back into the heat exchanger, or both. Heat pumps can be operated in different modes of operation, and segments of refrigerant conduit can be interconnected with various components.

  7. Refrigerant charge management in a heat pump water heater

    Science.gov (United States)

    Chen, Jie; Hampton, Justin W.

    2016-07-05

    Heat pumps that heat or cool a space and that also heat water, refrigerant management systems for such heat pumps, and methods of managing refrigerant charge. Various embodiments remove idle refrigerant from a heat exchanger that is not needed for transferring heat by opening a refrigerant recovery valve and delivering the idle refrigerant from the heat exchanger to an inlet port on the compressor. The heat exchanger can be isolated by closing an electronic expansion valve, actuating a refrigerant management valve, or both. Refrigerant charge can be controlled by controlling how much refrigerant is drawn from the heat exchanger, by letting some refrigerant back into the heat exchanger, or both. Heat pumps can be operated in different modes of operation, and various components can be interconnected with refrigerant conduit. Some embodiments deliver refrigerant gas to the heat exchanger and drive liquid refrigerant out prior to isolating the heat exchanger.

  8. Techno-economic appraisal of an integrated collector-storage solar water heater

    Energy Technology Data Exchange (ETDEWEB)

    Smyth, M.; Eames, P.C.; Norton, B. [University of Ulster, Newtownabbey (United Kingdom). School of the Built Environment

    2004-07-01

    Integrated collector/storage solar water heaters, due to their simple compact structure and inherent freeze protection, offer a promising approach for solar water heating in colder climates. Such a system, designed specifically for application at a Northern latitude, has been developed incorporating a heat retaining storage vessel mounted within a concentrating cusp reflector supported by a novel exo-skeleton framework. The performance was determined experimentally under real operational conditions in the Northern Irish climate. A detailed cost analysis is presented and payback periods, substituting different local fuel/power sources, determined. (author)

  9. Solar-powered hot-water system

    Science.gov (United States)

    Collins, E. R.

    1979-01-01

    Hot-water system requires no external power except solar energy. System is completely self-controlling. It includes solar-powered pump, solar-thermally and hydrothermally operated valves, and storage tank filled with open-celled foam, to maintain thermal stratification in stored water.

  10. Direct uses of hot water (geothermal) in dairying

    Energy Technology Data Exchange (ETDEWEB)

    Barmettler, E.R.; Rose, W.R. Jr.

    1978-01-01

    Digital computer simulation was used to investigate the peak, steady energy utilization of a geothermal energy-supported dairy. A digital computer program was also written to assess the lifetime economics of the dairy operation. A dynamic simulation program was written to design water storage tanks under diurnal transient loading. The geothermal site specified is the artesian spring named Hobo Wells near Susanville, California. The dairy configuration studies are unique, but consist of conventional processing equipment. In the dairy, cattle waste would be used to generate methane and carbon dioxide by anaerobic digestion. Some carbon dioxide would be removed from the gas stream with a pressurized water scrubber to raise the heating value. The product gas would be combusted in a spark ignition engine connected to an electric generator. The electrical power produced would be used for operation of fans, pumps, lights and other equipment in the dairy. An absorption chiller using a geothermal water driven generator would provide milk chilling. Space heating would be done with forced air hot water unit heaters.

  11. Analysis of the performance and space-conditioning impacts of dedicated heat-pump water heaters

    Energy Technology Data Exchange (ETDEWEB)

    Morrison, L.; Swisher, J.

    1980-12-01

    A description is given of the development and testing of the newly-marketed dedicated heat pump water heater (HPWH), and an analysis is presented of its performance and space conditioning impacts. This system utilizes an air-to-water heat pump, costs about $1000 installed, and obtains a coefficient of performance (COP) of about 2.0 in laboratory and field tests. Since a HPWH is usually installed indoors and extracts heat from the air, its operation is a space conditioning benefit if an air conditioning load exists and a penalty if a space heating load exists. To investigate HPWH performance and a space conditioning impacts, a simulation has been developed to model the thermal performance of a residence with resistance baseboard heat, air conditioning, and either heat pump or resistance water heating. The building characteristics are adapted for three US geographical areas (Madison, Wisconsin; Washington, DC; and Ft. Worth, Texas), and the system is simulated for a year with typical weather data. For each city, HPWH COPs are calculated monthly and yearly. In addition, the water heating and space conditioning energy requirements of HPWH operation are compared with those of resistance water heater operation to determine the relative performance ratio (RPR) of the HPWH. The annual simulated RPRs range from 1.5 to 1.7, which indicate a substantial space heating penalty of HPWH operation in these cities.

  12. Life cycle assessment of domestic heat pump hot water systems in Australia

    Directory of Open Access Journals (Sweden)

    Moore Andrew D.

    2017-01-01

    Full Text Available Water heating accounts for 23% of residential energy consumption in Australia, and, as over half is provided by electric water heaters, is a significant source of greenhouse gas emissions. Due to inclusion in rebate schemes heat pump water heating systems are becoming increasingly popular, but do they result in lower greenhouse gas emissions? This study follows on from a previous life cycle assessment study of domestic hot water systems to include heat pump systems. The streamlined life cycle assessment approach used focused on the use phase of the life cycle, which was found in the previous study to be where the majority of global warming potential (GWP impacts occurred. Data was collected from an Australian heat pump manufacturer and was modelled assuming installation within Australian climate zone 3 (AS/NZS 4234:2011. Several scenarios were investigated for the heat pumps including different sources of electricity (grid, photovoltaic solar modules, and batteries and the use of solar thermal panels. It was found that due to their higher efficiency heat pump hot water systems can result in significantly lower GWP than electric storage hot water systems. Further, solar thermal heat pump systems can have lower GWP than solar electric hot water systems that use conventional electric boosting. Additionally, the contributions of HFC refrigerants to GWP can be significant so the use of alternative refrigerants is recommended. Heat pumps combined with PV and battery technology can achieve the lowest GWP of all domestic hot water systems.

  13. Impact of Ducting on Heat Pump Water Heater Space Conditioning Energy Use and Comfort

    Energy Technology Data Exchange (ETDEWEB)

    Widder, Sarah H.; Petersen, Joseph M.; Parker, Graham B.; Baechler, Michael C.

    2014-07-21

    Increasing penetration of heat pump water heaters (HPWHs) in the residential sector will offer an important opportunity for energy savings, with a theoretical energy savings of up to 63% per water heater and up to 11% of residential energy use (EIA 2009). However, significant barriers must be overcome before this technology will reach widespread adoption in the Pacific Northwest region and nationwide. One significant barrier noted by the Northwest Energy Efficiency Alliance (NEEA) is the possible interaction with the homes’ space conditioning system for units installed in conditioned spaces. Such complex interactions may decrease the magnitude of whole-house savings available from HPWH installed in the conditioned space in cold climates and could lead to comfort concerns (Larson et al. 2011; Kresta 2012). Modeling studies indicate that the installation location of HPWHs can significantly impact their performance and the resultant whole-house energy savings (Larson et al. 2012; Maguire et al. 2013). However, field data are not currently available to validate these results. This field evaluation of two GE GeoSpring HPWHs in the PNNL Lab Homes is designed to measure the performance and impact on the Lab Home HVAC system of a GE GeoSpring HPWH configured with exhaust ducting compared to an unducted GeoSpring HPWH during heating and cooling season periods; and measure the performance and impact on the Lab Home HVAC system of the GeoSpring HPWH with both supply and exhaust air ducting as compared to an unducted GeoSpring HPWH during heating and cooling season periods. Important metrics evaluated in these experiments include water heater energy use, HVAC energy use, whole house energy use, interior temperatures (as a proxy for thermal comfort), and cost impacts. This technical report presents results from the PNNL Lab Homes experiment.

  14. Are hot-spots occluded from water?

    Science.gov (United States)

    Moreira, Irina Sousa; Ramos, Rui Miguel; Martins, Joao Miguel; Fernandes, Pedro Alexandrino; Ramos, Maria João

    2014-01-01

    Protein-protein interactions are the basis of many biological processes and are governed by focused regions with high binding affinities, the warm- and hot-spots. It was proposed that these regions are surrounded by areas with higher packing density leading to solvent exclusion around them - "the O-ring theory." This important inference still lacks sufficient demonstration. We have used Molecular Dynamics (MD) simulations to investigate the validity of the O-ring theory in the context of the conformational flexibility of the proteins, which is critical for function, in general, and for interaction with water, in particular. The MD results were analyzed for a variety of solvent-accessible surface area (SASA) features, radial distribution functions (RDFs), protein-water distances, and water residence times. The measurement of the average solvent-accessible surface area features for the warm- and hot-spots and the null-spots, as well as data for corresponding RDFs, identify distinct properties for these two sets of residues. Warm- and hot-spots are found to be occluded from the solvent. However, it has to be borne in mind that water-mediated interactions have significant power to construct an extensive and strongly bonded interface. We observed that warm- and hot-spots tend to form hydrogen bond (H-bond) networks with water molecules that have an occupancy around 90%. This study provides strong evidence in support of the O-ring theory and the results show that hot-spots are indeed protected from the bulk solvent. Nevertheless, the warm- and hot-spots still make water-mediated contacts, which are also important for protein-protein binding.

  15. Heat Pump Water Heater Ducting Strategies with Encapsulated Attics in Climate Zones 2 and 4

    Energy Technology Data Exchange (ETDEWEB)

    Sweet, M. L. [Southface Energy Inst., Atlanta, GA (United States); Francisco, A. [Southface Energy Inst., Atlanta, GA (United States); Roberts, S. G. [Southface Energy Inst., Atlanta, GA (United States)

    2016-05-01

    The focus of this study is on the performance of HPWHs with several different duct configurations and their effects on whole building heating, cooling, and moisture loads. A.O. Smith 60 gallon Voltex (PHPT-60) heat pump water heaters (HPWHs) were included at two project sites and ducted to or located within spray foamed encapsulated attics. The effect of ducting a HPWH's air stream does not diminish its efficiency if the ducting does not reduce intake air temperature, which expands HPWH application to confined areas.

  16. Balancing of hot water distribution networks; Equilibrage des reseaux de distribution

    Energy Technology Data Exchange (ETDEWEB)

    Fridmann, P. [Societe Comap SA (France)

    1998-10-01

    The hydraulic balancing of hot water distribution networks is of prime importance for the optimum exploitation of air-conditioning installations. In the case of a non-correct balancing, heat exchangers, hot or cold batteries, water heaters or convection heaters are supplied by an insufficient or excessive water flow rate which disturbs the thermal equilibrium of the system and its correct regulation. The result is a degradation of the thermal comfort and a loss of energy. The aim of this technical paper is to precise the conditions of a good hydraulic (and thermal) balancing and the main rules to apply in order to avoid difficulties and counter-performances in space heating installations. The examples are restricted to closed and ramified hot or cold water networks and to a qualitative description of the phenomena: 1 - generalities (terminology, pressure drops, Z coefficients, network-pump coupling, thermosiphon effect, flow rate adjustment, flow and/or differential pressure regulation); 2 - application to the balancing of new installations (networks calculation principles, determination and adjustment of balancing equipments, follow up of hydraulic characteristics and prevention of disturbances); 3 - application to the balancing of existing installations; 4 - perspectives of evolution. (J.S.) 21 refs.

  17. Thermal Performance of Solar Hot Water Systems Using a Flat Plate Collector of Accelerated Risers

    Directory of Open Access Journals (Sweden)

    KE Amori

    2012-06-01

    Full Text Available This study focuses on a comparison of the performance of two similar locally-fabricated solar water heaters. One of the collectors features a new design for accelerated absorber; its risers are made of converging ducts whose exit area is half that of the entrance. The other collector is a conventional absorber, with risers of the same cross sectional area along its length. Each collector is the primary part of an indirect thermosyphon circulation solar hot water system. Both collectors face south with a fixed tilt angle of 33.3

  18. Demonstration of a Solar Thermal Combined Heating, Cooling and Hot Water System Utilizing an Adsorption Chiller for DoD Installations

    Science.gov (United States)

    2013-12-01

    Monitored. Chiller auxiliary (air compressor/ dryer ) PM5601/2 0.22 kW Variable load, average when solar field not operating. Tank heaters PM5601/2...FINAL REPORT Demonstration of a Solar Thermal Combined Heating, Cooling and Hot Water System Utilizing an Adsorption Chiller for DoD...Demonstration of a Solar Thermal Combined Heating, Cooling and Hot Water System Utilizing an Adsorption Chiller for DoD 5b. GRANT NUMBER 5c

  19. Experimental Study on the Performance of Water Source Trans-Critical CO2 Heat Pump Water Heater

    OpenAIRE

    Xiufang Liu; Changhai Liu; Ze Zhang; Liang Chen; Yu Hou

    2017-01-01

    The effect of the discharge pressure on the performance of the trans-critical CO2 heat pump with a low gas-cooler outlet temperature is experimentally investigated on a test rig of water source heat-pump water heater. The optimal discharge pressure of the trans-critical CO2 heat pump is investigated under different external operation conditions. When the tap-water temperature is low, the characteristic of the S-shape isotherm at the supercritical region has little effect on the occurrence of ...

  20. 7 CFR 305.22 - Hot water immersion treatment schedules.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 5 2010-01-01 2010-01-01 false Hot water immersion treatment schedules. 305.22... Hot water immersion treatment schedules. (a) T102-d. (1) Fruit must be grown and treated in Hawaii. (2) Fruit must be submerged at least 4 inches below the water's surface in a hot water immersion treatment...

  1. Effect of Fuel Wobbe Number on Pollutant Emissions from Advanced Technology Residential Water Heaters: Results of Controlled Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Rapp, Vi H.; Singer, Brett C.

    2014-03-01

    The research summarized in this report is part of a larger effort to evaluate the potential air quality impacts of using liquefied natural gas in California. A difference of potential importance between many liquefied natural gas blends and the natural gas blends that have been distributed in California in recent years is the higher Wobbe number of liquefied natural gas. Wobbe number is a measure of the energy delivery rate for appliances that use orifice- or pressure-based fuel metering. The effect of Wobbe number on pollutant emissions from residential water heaters was evaluated in controlled experiments. Experiments were conducted on eight storage water heaters, including five with “ultra low-NO{sub X}” burners, and four on-demand (tankless) water heaters, all of which featured ultra low-NO{sub X} burners. Pollutant emissions were quantified as air-free concentrations in the appliance flue and fuel-based emission factors in units of nanogram of pollutant emitter per joule of fuel energy consumed. Emissions were measured for carbon monoxide (CO), nitrogen oxides (NO{sub X}), nitrogen oxide (NO), formaldehyde and acetaldehyde as the water heaters were operated through defined operating cycles using fuels with varying Wobbe number. The reference fuel was Northern California line gas with Wobbe number ranging from 1344 to 1365. Test fuels had Wobbe numbers of 1360, 1390 and 1420. The most prominent finding was an increase in NO{sub X} emissions with increasing Wobbe number: all five of the ultra low-NO{sub X} storage water heaters and two of the four ultra low-NO{sub X} on-demand water heaters had statistically discernible (p<0.10) increases in NO{sub X} with fuel Wobbe number. The largest percentage increases occurred for the ultra low-NO{sub X} water heaters. There was a discernible change in CO emissions with Wobbe number for all four of the on-demand devices tested. The on-demand water heater with the highest CO emissions also had the largest CO increase

  2. Estimation of energy consumption for domestic hot water in hospitals

    Energy Technology Data Exchange (ETDEWEB)

    Katsanis, J.S.; Tsarabaris, P.T.; Bourkas, P.D. [National Technical Univ. of Athens, Athens (Greece). Dept. of Electrical and Computer Engineering; Halaris, P.G. [Asklepieon Voulas General Hospital, Athens (Greece). Electrical Engineering Dept. of Biomedical Technology; Malahias, G.N. [Hellenic Naval Academy, Athens (Greece)

    2006-07-01

    Hospitals are among the largest energy consumers in the building sector, with hot water constituting the largest part of the base load which consists of partial loads for heating, sanitary hot water, sterilization, disinfection, kitchen thermal load and laundry thermal load. This study estimated the energy consumption for domestic hot water (DHW) for Greek hospitals. The purpose was to evaluate the feasibility of using cogeneration systems in hospitals, which would combine electric and thermal energy from the same energy source. In this study, only the data for the consumption of DHW was presented. DHW in Greek hospitals is 45 degrees C except for the kitchen, laundry and anatomic room supply where hot water reaches 65 degrees C. Water consumption varies considerably depending on the condition of the hospital and extent of outpatients and clinical provisions. Hot water production is typically achieved in thermal substations through hot water production centres that include hot water storage tanks; heat exchangers; heating medium circuits; pipework for domestic hot water and connection with cold water supply. This presentation described the sizing of the DHW system and estimated the simultaneity factor for hot and cold water in hospitals. The hot water demand curve was used to estimate the energy consumption per day for hot water based on 18 hours of operation. Assuming that the hot water demand curve is typical, the energy consumption was estimated for sanitary hot water per day as a function of the specific water consumption for hospital with different number of beds. The hot water energy use was nearly 50 kWh per cubic meter water. The thermal losses in the hot water piping network were not considered in this study. 17 refs., 6 tabs., 6 figs.

  3. Solar heating and domestic hot water system installed at Kansas City, Fire Station, Kansas City, Missouri. Final report

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-07-01

    This document is the final report of the solar energy heating and hot water system installed at the Kansas City Fire Station, Number 24, 2309 Hardesty Street, Kansas City, Missouri. The solar system was designed to provide 47 percent of the space heating, 8800 square feet area and 75 percent of the domestic hot water (DHW) load. The solar system consists of 2808 square feet of Solaron, model 2001, air, flat plate collector subsystem, a concrete box storage subsystem which contains 1428 cubic feet of 1/2 inch diameter pebbles weighing 71 1/2 tons, a DHW preheat tank, blowers, pumps, heat exchangers, air ducting, controls and associated plumbing. Two 120-gallon electric DHW heaters supply domestic hot water which is preheated by the solar system. Auxiliary space heating is provided by three electric heat pumps with electric resistance heaters and four 30-kilowatt electric unit heaters. There are six modes of system operation. This project is part of the Department of Energy PON-1 Solar Demonstration Program with DOE cost sharing $154,282 of the $174,372 solar system cost. The Final Design Review was held March 1977, the system became operational March 1979 and acceptance test was completed in September 1979.

  4. In-situ tuff water migration/heater experiment: experimental plan

    Energy Technology Data Exchange (ETDEWEB)

    Johnstone, J.K.

    1980-08-01

    Tuffs on the Nevada Test Site (NTS) are currently under investigation as a potential isolation medium for heat-producing nuclear wastes. The National Academy of Sciences has concurred in our identification of the potentially large water content ({le}40 vol %) of tuffs as one of the important issues affecting their suitability for a repository. This Experimental Plan describes an in-situ experiment intended as an initial assessment of water generation/migration in response to a thermal input. The experiment will be conducted in the Grouse Canyon Welded Tuff in Tunnel U12g (G-Tunnel) located in the north-central region of the NTS. While the Grouse Canyon Welded Tuff is not a potential repository medium, it has physical, thermal, and mechanical properties very similar to those tuffs currently under consideration and is accessible at depth (400 m below the surface) in an existing facility. Other goals of the experiment are to support computer-code and instrumentation development, and to measure in-situ thermal properties. The experimental array consists of a central electrical heater, 1.2 m long x 10.2 cm diameter, surrounded by three holes for measuring water-migration behavior, two holes for measuring temperature profiles, one hole for measuring thermally induced stress in the rock, and one hole perpendicular to the heater to measure displacement with a laser. This Experimental Plan describes the experimental objectives, the technical issues, the site, the experimental array, thermal and thermomechanical modeling results, the instrumentation, the data-acquisition system, posttest characterization, and the organizational details.

  5. 21 CFR 880.6085 - Hot/cold water bottle.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Hot/cold water bottle. 880.6085 Section 880.6085... Devices § 880.6085 Hot/cold water bottle. (a) Identification. A hot/cold water bottle is a device intended for medical purposes that is in the form of a container intended to be filled with hot or cold water...

  6. Residential energy-tax-credit eligibility: a case study for the heat-pump water heater

    Energy Technology Data Exchange (ETDEWEB)

    Cohn, S M; Cardell, N S

    1982-09-01

    Described are the methodology and results of an analysis to determine the eligibility of an energy-efficient item for the residential energy-tax credit. Although energy credits are granted only on a national basis, an attempt to determine the tax-credit eligibility for an item such as the heat-pump water heater (HPWH) analyzing national data is inappropriate. The tax-credit eligibility of the HPWH is evaluated for the ten federal regions to take into consideration the regional differences of: (1) HPWH annual efficiency, (2) existing water heater stocks by fuel type, (3) electricity, fuel oil, and natural-gas price variations, and (4) electric-utility oil and gas use for electricity generation. A computer model of consumer choice of HPWH selection as well as a computer code evaluating the economics of tax-credit eligibility on a regional basis were developed as analytical tools for this study. The analysis in this report demonstrates that the HPWH meets an important criteria for eligibility by the Treasury Department for an energy tax credit (nationally, the estimated dollar value of savings of oil and gas over the lifetime of those HPWH's sold during 1981 to 1985 due to the tax credit exceeds the revenue loss to the treasury). A natural-gas price-deregulation scenario is one of two fuel scenarios that are evaluated using the equipment choice and tax-credit models. These two cases show the amounts of oil and gas saved by additional HPWH units sold (due to the tax credit during 1981 to 1985 (range from 13.9 to 23.1 million barrels of oil equivalent over the lifetime of the equipment.

  7. Commercialization of air conditioning heat pump/water heater. Final technical report, Volume 1: Transmittal documents; Executive summary; Project summary

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-01-30

    This is the final technical report on a commercialization project for an air conditioning heat pump water heater. The objective of the project was to produce a saleable system which would be economically competitive with natural gas and cost effective with regard to initial cost versus annual operating costs. The development and commercialization of the system is described.

  8. Experimental validation of dynamic simulation of the flat plate collector in a closed thermosyphon solar water heater

    DEFF Research Database (Denmark)

    Taherian, H.; Kolaei, Alireza Rezania; Sadeghi, S.

    2011-01-01

    This work studies the dynamic simulation of thermosyphon solar water heater collector considering the weather conditions of a city in north of Iran. The simulation was done for clear and partly cloudy days. The useful energy, the efficiency diagrams, the inlet and the outlet of collector, center...

  9. Analysis of solar water heater with parabolic dish concentrator and conical absorber

    Science.gov (United States)

    Rajamohan, G.; Kumar, P.; Anwar, M.; Mohanraj, T.

    2017-06-01

    This research focuses on developing novel technique for a solar water heating system. The novel solar system comprises a parabolic dish concentrator, conical absorber and water heater. In this system, the conical absorber tube directly absorbs solar radiation from the sun and the parabolic dish concentrator reflects the solar radiations towards the conical absorber tube from all directions, therefore both radiations would significantly improve the thermal collector efficiency. The working fluid water is stored at the bottom of the absorber tubes. The absorber tubes get heated and increases the temperature of the working fluid inside of the absorber tube and causes the working fluid to partially evaporate. The partially vaporized working fluid moves in the upward direction due to buoyancy effect and enters the heat exchanger. When fresh water passes through the heat exchanger, temperature of the vapour decreases through heat exchange. This leads to condensation of the vapour and forms liquid phase. The working fluid returns to the bottom of the collector absorber tube by gravity. Hence, this will continue as a cyclic process inside the system. The proposed investigation shows an improvement of collector efficiency, enhanced heat transfer and a quality water heating system.

  10. Assessing Consumer Values and the Supply-Chain Market for the Integrated Water Heater/Dehumidifier

    Energy Technology Data Exchange (ETDEWEB)

    Ashdown, BG

    2005-01-11

    This paper presents a case study of the potential market for the dual-service residential integrated water heater/dehumidifier (WHD). Its principal purpose is to evaluate the extent to which this integrated appliance might penetrate the residential market sector, given current market trends, producer and consumer attributes, and technical parameters. The report's secondary purpose is to gather background information leading to a generic framework for conducting market analyses of technologies. This framework can be used to assess market readiness as well as factor preferred product attributes into the design to drive consumer demand for this product. This study also supports analysis for prototype design. A full market analysis for potential commercialization should be conducted after prototype development. The integrated WHD is essentially a heat-pump water heater (HPWH) with components and controls that allow dedicated dehumidification. Adequate residential humidity control is a growing issue for newly constructed residential homes, which are insulated so well that mechanical ventilation may be necessary to meet fresh air requirements. Leveraging its successful experience with the energy-efficient design improvement for the residential HPWH, the Oak Ridge National Laboratory's (ORNL's) Engineering Science and Technology Division's (ESTD's) Building Equipment Group designed a water-heating appliance that combines HPWH efficiency with dedicated dehumidification. This integrated appliance could be a low-cost solution for dehumidification and efficient electric water heating. ORNL is partnering with Western Carolina University, Asheville-Buncombe Technical Community College, American Carolina Stamping Company, and Clemson University to develop this appliance and assess its market potential. For practical purposes, consumers are indifferent to how water is heated but are very interested in product attributes such as initial first cost

  11. Numerical analysis of using hybrid photovoltaic-thermal solar water heater in Iran

    Directory of Open Access Journals (Sweden)

    M Mohammadi Sarduei

    2017-05-01

    Full Text Available Introduction Electrical performance of solar cells decreases with increasing cell temperature, basically because of growth of the internal charge carrier recombination rates, caused by increased carrier concentrations. Hybrid Photovoltaic/thermal (PVT systems produce electrical and thermal energy simultaneously. PVT solar collectors convert the heat generated in the solar cells to low temperature useful heat energy and so they provide a lower working temperature for solar cells which subsequently leads to a higher electrical efficiency. Recently, in Iran, the reforming government policy in subsidy and increasing fossil fuels price led to growing an interest in use of renewable energies for residual and industrial applications. In spite of this, the PV power generator investment is not economically feasible, so far. Hybrid PVT devices are well known as an alternative method to improve energy performance and therefore economic feasibility of the conventional PV systems. The aim of this study is to investigate the performance of a PVT solar water heater in four different cities of Iran using TRNSYS program. Materials and Methods The designed PVT solar water system consists of two separate water flow circuits namely closed cycle and open circuit. The closed cycle circuit was comprised of a solar PVT collector (with nominal power of 880 W and area of 5.6 m2, a heat exchanger in the tank (with volume of 300 L, a pump and connecting pipes. The water stream in the collector absorbs the heat accumulated in the solar cells and delivers it to the water in the tank though the heat exchanger. An on/off controller system was used to activate the pump when the collector outlet temperature was higher than that of the tank in the closed cycle circuit. The water in the open circuit, comes from city water at low temperature, enters in the lower part of the storage tank where the heat transfer occurs between the two separate circuits. An auxiliary heater, connected

  12. Experimental Study on the Performance of Water Source Trans-Critical CO2 Heat Pump Water Heater

    Directory of Open Access Journals (Sweden)

    Xiufang Liu

    2017-06-01

    Full Text Available The effect of the discharge pressure on the performance of the trans-critical CO2 heat pump with a low gas-cooler outlet temperature is experimentally investigated on a test rig of water source heat-pump water heater. The optimal discharge pressure of the trans-critical CO2 heat pump is investigated under different external operation conditions. When the tap-water temperature is low, the characteristic of the S-shape isotherm at the supercritical region has little effect on the occurrence of the optimal discharge pressure; while the mass flow rate of CO2, the suction pressure and the gas-cooler outlet temperature play a significant role in determining the emergence of the optimal discharge pressure. At the optimal discharge pressure, the COP reaches the peak; however, the corresponding heating capacity is still lower than its maximum, which is reached as the discharge pressure is slightly above the optimal discharge pressure. Reducing the tap-water flowrate or increasing the water-source temperature can increase the optimal discharge pressure. The COP is positively dependent on both the tap-water flowrate and the water-source temperature. In addition, the tap-water flowrate has a negligible influence on the maximum heating capacity while increasing the water-source temperature can greatly enhance the heating capacity.

  13. West Village Community: Quality Management Processes and Preliminary Heat Pump Water Heater Performance

    Energy Technology Data Exchange (ETDEWEB)

    Dakin, B.; Backman, C.; Hoeschele, M.; German, A.

    2012-11-01

    West Village, a multi-use project underway at the University of California Davis, represents a ground-breaking sustainable community incorporating energy efficiency measures and on-site renewable generation to achieve community-level Zero Net Energy (ZNE) goals. The project when complete will provide housing for students, faculty, and staff with a vision to minimize the community's impact on energy use by reducing building energy use, providing on-site generation, and encouraging alternative forms of transportation. This focus of this research is on the 192 student apartments that were completed in 2011 under Phase I of the West Village multi-year project. The numerous aggressive energy efficiency measures implemented result in estimated source energy savings of 37% over the B10 Benchmark. There are two primary objectives of this research. The first is to evaluate performance and efficiency of the central heat pump water heaters as a strategy to provide efficient electric water heating for net-zero all-electric buildings and where natural gas is not available on site. In addition, effectiveness of the quality assurance and quality control processes implemented to ensure proper system commissioning and to meet program participation requirements is evaluated. Recommendations for improvements that could improve successful implementation for large-scale, high performance communities are identified.

  14. West Village Community. Quality Management Processes and Preliminary Heat Pump Water Heater Performance

    Energy Technology Data Exchange (ETDEWEB)

    Dakin, B. [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States); Backman, C. [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States); Hoeschele, M. [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States); German, A. [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States)

    2012-11-01

    West Village, a multi-use project underway at the University of California Davis, represents a ground-breaking sustainable community incorporating energy efficiency measures and on-site renewable generation to achieve community-level Zero Net Energy (ZNE) goals. When complete, the project will provide housing for students, faculty, and staff with a vision to minimize the community’s impact on energy use by reducing building energy use, providing on-site generation, and encouraging alternative forms of transportation. This focus of this research is on the 192 student apartments that were completed in 2011 under Phase I of the West Village multi-year project. The numerous aggressive energy efficiency measures implemented result in estimated source energy savings of 37% over the B10 Benchmark. There are two primary objectives of this research. The first is to evaluate performance and efficiency of the central heat pump water heaters as a strategy to provide efficient electric water heating for net-zero all-electric buildings and where natural gas is not available on site. In addition, effectiveness of the quality assurance and quality control processes implemented to ensure proper system commissioning and to meet program participation requirements is evaluated. Recommendations for improvements that could improve successful implementation for large-scale, high performance communities are identified.

  15. Technology Solutions for New and Existing Homes Case Study: Addressing Multifamily Piping Losses with Solar Hot Water

    Energy Technology Data Exchange (ETDEWEB)

    D. Springer, M. Seitzler, and C. Backman

    2016-12-01

    Sun Light & Power, a San Francisco Bay Area solar design-build contractor, teamed with the U.S. Department of Energy’s Building America partner the Alliance for Residential Building Innovation (ARBI) to study this heat-loss issue. The team added three-way valves to the solar water heating systems for two 40-unit multifamily buildings. In these systems, when the stored solar hot water is warmer than the recirculated hot water returning from the buildings, the valves divert the returning water to the solar storage tank instead of the water heater. This strategy allows solar-generated heat to be applied to recirculation heat loss in addition to heating water that is consumed by fixtures and appliances.

  16. Dimensioning of a solar water heater made from PET bottles; Dimensionamento de um aquecedor solar de agua feito com garrafas PET

    Energy Technology Data Exchange (ETDEWEB)

    Bertoleti, Pedro Henrique Fonseca; Souza, Teofilo Miguel de [Universidade Estadual Paulista (UNESP), Guaratingueta, SP (Brazil). Centro de Energias Renovaveis

    2008-07-01

    This document show the solar water heater made of PET bottles, a simple-construction solar water heater that try to give us two important solutions, water heating using solar energy and reutilization of the PET bottles left in the nature. Also, it will be showed how to do the dimensioning of it. Based on the showed dimensioning a application / software is developed and after that simulations are made using the application to provide how is the economy if it's used this kind of solar water heater and their environmental contribution by reutilization of the PET bottles abandoned in the nature. For example, in a common home the economy is about 45% of the electricity bill considering that the warmed water is used just to take a shower. So, the conclusion is: the solar water heater made by PET bottles is a very relevant equipment to the use of the solar energy, to useful applications and environmental contribution. (author)

  17. Sugar cane bagasse prehydrolysis using hot water

    Directory of Open Access Journals (Sweden)

    D. Abril

    2012-03-01

    Full Text Available Results are presented on the hot water prehydrolysis of sugar cane bagasse for obtaining ethanol by fermentation. The experimental study consisted of the determination of the effect of temperature and time of prehydrolysis on the extraction of hemicelluloses, with the objective of selecting the best operating conditions that lead to increased yield of extraction with a low formation of inhibitors. The study, carried out in a pilot plant scale rotational digester, using a 3² experimental design at temperatures of 150-190ºC and times of 60-90 min, showed that it is possible to perform the hot water prehydrolysis process between 180-190ºC in times of 60-82 min, yielding concentrations of xylose > 35 g/L, furfural < 2.5 g/L, phenols from soluble lignin < 1.5 g/L, and concentrations < 3.0 g/L of hemicelluloses in the cellolignin residue. These parameters of temperature and prehydrolysis time could be used for the study of the later hydrolysis and fermentation stages of ethanol production from sugar cane bagasse.

  18. Entrance Effects in Solar Hot Water Stores

    DEFF Research Database (Denmark)

    Shah, Louise Jivan; Furbo, Simon

    2003-01-01

    A theoretical and experimental analysis of water jets entering a solar storage tank is performed. CFD calculations of three inlet designs with different inlet flow rates were carried out to illustrate the varying behaviour of the thermal conditions in a solar store. The results showed the impact...... of the inlet design on the flow patterns in the tank and thus how the energy quality in a hot water tank is reduced with a poor inlet design. The numerical investigations were followed by experiments. A test solar store, similar to the store investigated by numerical modelling was constructed with cylindrical...... transparent walls so that the flow structures due to the inlet jets could be visualized. With the three inlets, nine draw-off tests with different inlet flow rates were carried out and the temperature stratification in the tank was measured during the draw-offs. The experimental results were used...

  19. Convective Mixing in Distal Pipes Exacerbates Legionella pneumophila Growth in Hot Water Plumbing

    Directory of Open Access Journals (Sweden)

    William J. Rhoads

    2016-03-01

    Full Text Available Legionella pneumophila is known to proliferate in hot water plumbing systems, but little is known about the specific physicochemical factors that contribute to its regrowth. Here, L. pneumophila trends were examined in controlled, replicated pilot-scale hot water systems with continuous recirculation lines subject to two water heater settings (40 °C and 58 °C and three distal tap water use frequencies (high, medium, and low with two pipe configurations (oriented upward to promote convective mixing with the recirculating line and downward to prevent it. Water heater temperature setting determined where L. pneumophila regrowth occurred in each system, with an increase of up to 4.4 log gene copies/mL in the 40 °C system tank and recirculating line relative to influent water compared to only 2.5 log gene copies/mL regrowth in the 58 °C system. Distal pipes without convective mixing cooled to room temperature (23–24 °C during periods of no water use, but pipes with convective mixing equilibrated to 30.5 °C in the 40 °C system and 38.8 °C in the 58 °C system. Corresponding with known temperature effects on L. pneumophila growth and enhanced delivery of nutrients, distal pipes with convective mixing had on average 0.2 log more gene copies/mL in the 40 °C system and 0.8 log more gene copies/mL in the 58 °C system. Importantly, this work demonstrated the potential for thermal control strategies to be undermined by distal taps in general, and convective mixing in particular.

  20. Detection of Hot Halo Gets Theory Out of Hot Water

    Science.gov (United States)

    2006-02-01

    Scientists using NASA's Chandra X-ray Observatory have detected an extensive halo of hot gas around a quiescent spiral galaxy. This discovery is evidence that galaxies like our Milky Way are still accumulating matter from the gradual inflow of intergalactic gas. "What we are likely witnessing here is the ongoing galaxy formation process," said Kristian Pedersen of the University of Copenhagen, Denmark, and lead author of a report on the discovery. Chandra observations show that the hot halo extends more than 60,000 light years on either side of the disk of the galaxy known as NGC 5746. The detection of such a large halo alleviates a long-standing problem for the theory of galaxy formation. Spiral galaxies are thought to form from enormous clouds of intergalactic gas that collapse to form giant, spinning disks of stars and gas. Chandra X-ray Image of NGC 5746 Chandra X-ray Image of NGC 5746 One prediction of this theory is that large spiral galaxies should be immersed in halos of hot gas left over from the galaxy formation process. Hot gas has been detected around spiral galaxies in which vigorous star formation is ejecting matter from the galaxy, but until now hot halos due to infall of intergalactic matter have not been detected. "Our observations solve the mystery of the missing hot halos around spiral galaxies," said Pedersen. "The halos exist, but are so faint that an extremely sensitive telescope such as Chandra is needed to detect them." DSS Optical Image of NGC 5746 DSS Optical Image of NGC 5746 NGC 5746 is a massive spiral galaxy about a 100 million light years from Earth. Its disk of stars and gas is viewed almost edge-on. The galaxy shows no signs of unusual star formation, or energetic activity from its nuclear region, making it unlikely that the hot halo is produced by gas flowing out of the galaxy. "We targeted NGC 5746 because we thought its distance and orientation would give us the best chance to detect a hot halo caused by the infall of

  1. Building America Case Study: Multifamily Central Heat Pump Water Heaters, Davis, California

    Energy Technology Data Exchange (ETDEWEB)

    M. Hoeschele, E. Weitzel

    2017-03-01

    Although heat pump water heaters (HPWHs) have gained significant attention in recent years as a high efficiency electric water heating solution for single family homes, central HPWHs for commercial or multi-family applications are not as well documented in terms of measured performance and cost effectiveness. To evaluate this technology, the Alliance for Residential Building Innovation team monitored the performance of a 10.5 ton central HPWH installed on a student apartment building at the West Village Zero Net Energy Community in Davis, California. Monitoring data collected over a 16-month period were then used to validate a TRNSYS simulation model. The TRNSYS model was then used to project performance in different climates using local electric rates. Results of the study indicate that after some initial commissioning issues, the HPWH operated reliably with an annual average efficiency of 2.12 (Coefficient of Performance). The observed efficiency was lower than the unit's rated efficiency, primarily due to the fact that the system rarely operated under steady-state conditions. Changes in the system configuration, storage tank sizing, and control settings would likely improve the observed field efficiency. Modeling results suggest significant energy savings relative to electric storage water heating systems (typical annual efficiencies around 0.90) providing for typical simple paybacks of six to ten years without any incentives. The economics versus gas water heating are currently much more challenging given the current low natural gas prices in much of the country. Increased market size for this technology would benefit cost effectiveness and spur greater technology innovation.

  2. Building America Case Study: Multifamily Central Heat Pump Water Heaters, Davis, California

    Energy Technology Data Exchange (ETDEWEB)

    2017-03-08

    Although heat pump water heaters (HPWHs) have gained significant attention in recent years as a high efficiency electric water heating solution for single family homes, central HPWHs for commercial or multi-family applications are not as well documented in terms of measured performance and cost effectiveness. To evaluate this technology, the Alliance for Residential Building Innovation team monitored the performance of a 10.5 ton central HPWH installed on a student apartment building at the West Village Zero Net Energy Community in Davis, California. Monitoring data collected over a 16-month period were then used to validate a TRNSYS simulation model. The TRNSYS model was then used to project performance in different climates using local electric rates. Results of the study indicate that after some initial commissioning issues, the HPWH operated reliably with an annual average efficiency of 2.12 (Coefficient of Performance). The observed efficiency was lower than the unit's rated efficiency, primarily due to the fact that the system rarely operated under steady-state conditions. Changes in the system configuration, storage tank sizing, and control settings would likely improve the observed field efficiency. Modeling results suggest significant energy savings relative to electric storage water heating systems (typical annual efficiencies around 0.90) providing for typical simple paybacks of six to ten years without any incentives. The economics versus gas water heating are currently much more challenging given the current low natural gas prices in much of the country. Increased market size for this technology would benefit cost effectiveness and spur greater technology innovation.

  3. Low Temperature District Heating Consumer Unit with Micro Heat Pump for Domestic Hot Water Preparation

    DEFF Research Database (Denmark)

    Zvingilaite, Erika; Ommen, Torben Schmidt; Elmegaard, Brian

    2012-01-01

    In this paper we present and analyse the feasibility of a district heating (DH) consumer unit with micro heat pump for domestic hot water (DHW) preparation in a low temperature (40 °C) DH network. We propose a micro booster heat pump of high efficiency (COP equal to 5,3) in a consumer DH unit...... in order to boost the temperature of the district heating water for heating the DHW. The paper presents the main designs of the suggested system and different alternative micro booster heat pump concepts. Energy efficiency and thermodynamic performance of these concepts are calculated and compared....... The results show that the proposed system has the highest efficiency. Furthermore, we compare thermodynamic and economic performance of the suggested heat pump-based concept with different solutions, using electric water heater. The micro booster heat pump system has the highest annualised investment (390 EUR...

  4. The Impact of Water Quality on the Use of Solar Water Heaters in Remote Islands of Taiwan

    Directory of Open Access Journals (Sweden)

    Kai-Chun Fan

    2016-11-01

    Full Text Available The use of solar water heaters (SWHs in Taiwan’s remote islands has been subjected to scaling and, in particular, corrosion problems due to sources of water. In this study, four different water quality indices including the Langelier Saturation Index (LSI, the Ryznar Stability Index (RSI, the Puckorius Scaling Index (PSI, and the Larson-Skold Corrosive Index (LSCI were employed to assess the scaling and corrosion tendencies in SWHs caused by tap water and ground water in the Penghu, Kinmen, and Lienchiang counties, each of which is constituted of several remote islands. In general, the LSI, the RSI, and the PSI results show a slight scaling tendency in Penghu, but a corrosion tendency in Kinmen and Lienchiang. Nevertheless, all LSCI results show a serious steel corrosion tendency in these three counties. In addition, the chloride ion (Cl− concentrations are higher than 45 mg/L in either tap water (except for the Lieyu township in Kinmen or ground water. This fact resulted in serious corrosion problems, as found in the currently installed SWHs, which were mainly made from 304 stainless steel. The metals with higher corrosion resistance to chloride ions are required in the manufacture of SWHs to be installed on these three remote-island counties.

  5. High Efficiency Water Heating Technology Development Final Report, Part II: CO2 and Absorption-Based Residential Heat Pump Water Heater Development

    Energy Technology Data Exchange (ETDEWEB)

    Gluesenkamp, Kyle R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Abdelaziz, Omar [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Patel, Viral K. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Mandel, Bracha T. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); de Almeida, Valmor F. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-05-01

    The two objectives of this project were to 1.demonstrate an affordable path to an ENERGY STAR qualified electric heat pump water heater (HPWH) based on low-global warming potential (GWP) CO2 refrigerant, and 2.demonstrate an affordable path to a gas-fired absorption-based heat pump water heater with a gas energy factor (EF) greater than 1.0. The first objective has been met, and the project has identified a promising low-cost option capable of meeting the second objective. This report documents the process followed and results obtained in addressing these objectives.

  6. Heat Pump Water Heater Ducting Strategies with Encapsulated Attics in Climate Zones 2 and 4

    Energy Technology Data Exchange (ETDEWEB)

    Sweet, M. L. [Southface Energy Inst., Upper Marlboro, MD (United States); Francisco, A.; Roberts, S. G.

    2016-05-01

    The focus of this study is on the performance of HPWHs with several different duct configurations and their effects on whole building heating, cooling, and moisture loads. A.O. Smith 60 gallon Voltex (PHPT-60) heat pump water heaters (HPWHs) were included at two project sites and ducted to or located within spray foamed encapsulated attics. The effect of ducting a HPWH's air stream does not diminish its efficiency if the ducting does not reduce intake air temperature, which expands HPWH application to confined areas. Exhaust ducts should be insulated to avoid condensation on the exterior, however this imposes a risk of condensation occurring in the duct's interior near the HPWH due to large variation of temperatures between the compressor and the duct and the presence of bulk moisture around the condenser. The HPWH's air conditioning impact on HVAC equipment loads is minimal when the intake and exhaust air streams are connected to a sealed attic and not the living space. A HPWH is not suitable as a replacement dehumidifier in sealed attics as peak moisture loads were observed to only be reduced if the heat pump operated during the morning. It appears that the intake air temperature and humidity was the most dominant variable affecting HPWH performance. Different ducting strategies such as exhaust duct only, intake duct only, and exhaust and intake ducting did not have any effect on HPWH performance.

  7. Design package for solar domestic hot water system

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-09-01

    Information used to evaluate the initial design of the Elcam, Inc., Solar Domestic Hot Water System is presented. Included are such items as the system performance specification, detailed design drawings and other information. Elcam, Inc., has developed two solar heated prototype hot water systems and two heat exchangers. The hot water systems consist of the following subsystems: collector, storage, control, transport, auxiliary energy, and government-furnished Site Data Acquisition. The two systems are installed at Tempe, Arizona, and San Diego, California.

  8. Bounding Limitations in the Practical Design of Adsorption Heat Pump Water Heaters

    Energy Technology Data Exchange (ETDEWEB)

    Ally, Moonis Raza [ORNL; Sharma, Vishaldeep [ORNL; Gluesenkamp, Kyle R [ORNL

    2016-01-01

    The boundary temperatures for any sorption-based technology can be estimated on the basis of Trouton s hypothesis that isosteres, extrapolated to infinite pressure (or analogously to infinite temperature) meet at a single point. In this paper we discuss the consequences of this hypothesis for many sorption devices that are thermally operated, suitable for exploiting renewable energy resources, or making better use of high or low level thermal energy. Trouton s hypothesis is independent of the working fluids making it particularly useful to both liquid-vapor and solid-vapor systems. We exemplify the use of the derived boundary temperatures derived from Trouton s hypothesis to important processes such as ice making, space cooling in hot climates, deep freezing, and residential hot water production. The boundary temperatures help determine which sorption or solar heating technology may be better suited to serve the given application, or whether it is beyond the scope of sorption systems.

  9. 207 EFFECTS OF HOT AND COLD WATER PRE- TREATMENTS ...

    African Journals Online (AJOL)

    no significant difference in the number of seeds that emerged from the cold water treatment (á = 0.05), while treatment with hot water showed significant differences among the treatment times. (á =0.05). Treatment of a. senegal seeds with hot water for 10 minutes gave the highest number of emerged seeds (mean, 7.50) ...

  10. Commercialization of air conditioning heat pump/water heater. Final technical report, Volume 2: Appendix A through E

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-01-30

    This is the final technical report on a commercialization project for an air conditioning heat pump water heater. The objective of the project was to produce a saleable system which would be economically competitive with natural gas and cost effective with regard to initial cost versus annual operating costs. The development and commercialization of the system is described. Compiled data included in numerous figures, tables and graphs.

  11. Prototype solar heating and hot water systems

    Science.gov (United States)

    1977-01-01

    Alternative approaches to solar heating and hot water system configurations were studied, parametrizing the number and location of the dampers, the number and location of the fans, the interface locations with the furnace, the size and type of subsystems, and operating modes. A two-pass air-heating collector was selected based on efficiency and ease of installation. Also, an energy transport module was designed to compactly contain all the mechanical and electrical control components. System performance calculations were carried out over a heating season for the tentative site location at Tunkhnana, Pa. Results illustrate the effect of collector size, storage capacity, and use of a reflector. Factors which affected system performance include site location, insulative quality of the house, and of the system components. A preliminary system performance specification is given.

  12. Application of solar energy to the supply of industrial process hot water. Aerotherm final report, 77-235. [Can washing in Campbell Soup plant

    Energy Technology Data Exchange (ETDEWEB)

    None

    1977-01-01

    The objectives of the Solar Industrial Process Hot Water Program are to design, test, and evaluate the application of solar energy to the generation and supply of industrial process hot water, and to provide an assessment of the economic and resource benefits to be gained. Other objectives are to stimulate and give impetus to the use of solar energy for supplying significant amounts of industrial process heat requirements. The plant selected for the design of a solar industrial process hot water system was the Campbell Soup facility in Sacramento, California. The total hot water demand for this plant varies between 500 and 800 gpm during regular production shifts, and hits a peak of over 1,000 gpm for approximately one hour during the cleanup shift. Most of the hot water is heated in the boiler room by a combination of waste heat recovery and low pressure (5 psi) steam-water heat exchangers. The hot water emerges from the boiler room at a temperature between 160/sup 0/F and 180/sup 0/F and is transported to the various process areas. Booster heaters in the process areas then use low pressure (5 psi) or medium pressure (20 psi) steam to raise the temperature of the water to the level required for each process. Hot water is used in several processes at the Campbell Soup plant, but the can washing process was selected to demonstrate the feasibility of a solar hot water system. A detailed design and economic analysis of the system is given. (WHK)

  13. Energy conservation in the production of domestic hot water

    Science.gov (United States)

    1981-12-01

    Improvements in energy efficiency in existing buildings and the construction of energy efficient buildings are discussed with emphasis on water heating. Cost effective measures proposed include fitting an 80-mm insulating jacket to the hot water storage cylinder, using time switches, fitting thermostatic control systems to boiler based central heating, and storing domestic hot water at a lower temperature. Research into the recovery of heat from waste water, the use of cold water detergents, and the use of heat pumps is urged.

  14. High Efficiency Water Heating Technology Development Final Report. Part I, Lab/Field Performance Evaluation and Accelerated Life Testing of a Hybrid Electric Heat Pump Water Heater (HPWH)

    Energy Technology Data Exchange (ETDEWEB)

    Baxter, Van D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Murphy, Richard W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Rice, C. Keith [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Linkous, Randall Lee [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-04-01

    DOE has supported efforts for many years with the objective of getting a water heater that uses heat pump technology (aka a heat pump water heater or HPWH) successfully on the residential equipment market. The most recent previous effort (1999-2002) produced a product that performed very well in ORNL-led accelerated durability and field tests. The commercial partner for this effort, Enviromaster International (EMI), introduced the product to the market under the trade name Watter$aver in 2002 but ceased production in 2005 due to low sales. A combination of high sales price and lack of any significant infrastructure for service after the sale were the principal reasons for the failure of this effort. What was needed for market success was a commercial partner with the manufacturing and market distribution capability necessary to allow economies of scale to lead to a viable unit price together with a strong customer service infrastructure. General Electric certainly meets these requirements, and knowing of ORNL s expertise in this area, approached ORNL with the proposal to partner in a CRADA to produce a high efficiency electric water heater. A CRADA with GE was initiated early in Fiscal Year, 2008. GE initially named its product the Hybrid Electric Water Heater (HEWH).

  15. Too hot to handle? Hot water bottle injuries in Sydney, Australia.

    Science.gov (United States)

    Goltsman, David; Li, Zhe; Bruce, Eleanor; Darton, Anne; Thornbury, Kelly; Maitz, Peter K M; Kennedy, Peter

    2015-06-01

    Hot water bottles are frequently used in the community as a source of warmth, and to alleviate a number of medical symptoms. In Australia it is believed that over 500,000 water bottles are sold annually (Whittam et al., 2010). This simple treatment is known to result in significant burns and has led to mandatory labeling requirements on hot water bottles in Australia. Despite this, few published studies have documented the incidence and nature of burns sustained through their use. This study aimed to assess the incidence, causation and outcome of hot water bottle burns presenting to a major burn trauma unit in Sydney (Australia). The New South Wales Agency for Clinical Innovation Statewide Burn Injury database and admission data to the Concord Hospital Burns Injury Unit (major treatment unit) provided information on hot water bottle burns occurring between 2005 and 2013. Demographic details, cause of burn, burn depth, total burn surface area (%TBSA), and outcome of burn were ascertained. In order to assess the burn potential of hot water bottles, a separate study examined the thermic properties of hot water bottles in 'real life' scenarios. There were 155 hot water bottle burn presentations resulting in 41 admissions and 24 grafts. The majority of patients were female, and most burns resulted from appliance rupture when used for local pain relief. Patients had an average TBSA of 2.4%. Burns patients were slightly more likely to reside in areas with greater socio-economic disadvantage. In real life scenarios, hot water bottles were shown to retain heat over 50°C for at least 3 hours (h). Hot water bottles are a source of common and preventable burns in the community, with women being more at risk than men. Hot water bottles may retain harmful levels of heat over an extended period of time. Additional labeling requirements pertaining to the longevity of hot water bottles and their use among people especially at risk of burns (i.e. children, the elderly, patients who

  16. YACON INULIN LEACHING DURING HOT WATER BLANCHING

    Directory of Open Access Journals (Sweden)

    Caroline Fenner Scher

    2015-10-01

    Full Text Available ABSTRACTYacon roots contain inulin, which has prebiotic properties and it may be used as sucrose or fat substitutes. However, inulin is very soluble in water. The loss of this important nutrient during blanching is caused mainly by diffusion or leaching, which might be diminished if blanching temperature - time conditions are correctly employed. The aim of this study was to determine the leaching of the sugars inulin, glucose and fructose, present in yacon roots, during hot water blanching under different time/temperature conditions. The samples were cleaned and peeled and cut into geometric forms of 1.75 ± 0.35 mm thick disks. A complete factorial experimental design was used, and the treatments of the samples were compared using the Tukey test. The results indicated that the time and temperature were significant in the dissolution of the sugars. The lowest inulin losses occurred at temperatures and times lower than 60 ºC and 3 minutes. For all temperatures, the lowest glucose and fructose losses were obtained at time lower than 3 and 5 minutes, respectively.

  17. Analysis Model for Domestic Hot Water Distribution Systems: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Maguire, J.; Krarti, M.; Fang, X.

    2011-11-01

    A thermal model was developed to estimate the energy losses from prototypical domestic hot water (DHW) distribution systems for homes. The developed model, using the TRNSYS simulation software, allows researchers and designers to better evaluate the performance of hot water distribution systems in homes. Modeling results were compared with past experimental study results and showed good agreement.

  18. Heat Losses Evaluation for Domestic Hot Water Distribution Systems

    Directory of Open Access Journals (Sweden)

    Theodor Mateescu

    2006-01-01

    Full Text Available In sanitary systems assembly, domestic hot water distribution supply networks represent an important weight for energetically balance.par This paper presents, in an analytical and graphical manner, the computational tools needed for domestic hot water piping system behavior characterization in different functional and structural assumptions.

  19. Prototype solar heating and cooling systems including potable hot water

    Science.gov (United States)

    1978-01-01

    Progress is reviewed in the development, delivery, and support of two prototype solar heating and cooling systems including potable hot water. The system consisted of the following subsystems: collector, auxiliary heating, potable hot water, storage, control, transport, and government-furnished site data acquisition.

  20. Investigations of hot water temperature changes at the pipe outflow

    Science.gov (United States)

    Wojtkowiak, Janusz; Oleśkowicz-Popiel, Czesław

    2017-11-01

    In this paper a process of cold water withdrawing from hot water supply pipe systems without recirculation is considered. System of partial differential equations was used to describe the pipe and water temperature changes. An exact solution of a simplified form of the equations was obtained and validated experimentally. The exact solution was applied to calculate the hot water temperature changes at the pipe outflow. Calculations were done for typical pipe materials (PP, PE, Cu), different pipe diameters and lengths as well as for various water flow rates. It was shown that in order to obtain the required hot water temperature in the tap, there is necessary to withdrawn much more (even two times) water from the pipe in comparison to the pipe volume. The reason of such significant water wastes is a heat exchange between hot water flowing inside the pipe and the colder pipe walls. The results can be useful for optimal selection of hot water supply pipes as well as for making decision about applying of hot water recirculating systems.

  1. Artificial Neural Networks-Based Software for Measuring Heat Collection Rate and Heat Loss Coefficient of Water-in-Glass Evacuated Tube Solar Water Heaters.

    Science.gov (United States)

    Liu, Zhijian; Liu, Kejun; Li, Hao; Zhang, Xinyu; Jin, Guangya; Cheng, Kewei

    2015-01-01

    Measurements of heat collection rate and heat loss coefficient are crucial for the evaluation of in service water-in-glass evacuated tube solar water heaters. However, conventional measurement requires expensive detection devices and undergoes a series of complicated procedures. To simplify the measurement and reduce the cost, software based on artificial neural networks for measuring heat collection rate and heat loss coefficient of water-in-glass evacuated tube solar water heaters was developed. Using multilayer feed-forward neural networks with back-propagation algorithm, we developed and tested our program on the basis of 915 measured samples of water-in-glass evacuated tube solar water heaters. This artificial neural networks-based software program automatically obtained accurate heat collection rate and heat loss coefficient using simply "portable test instruments" acquired parameters, including tube length, number of tubes, tube center distance, heat water mass in tank, collector area, angle between tubes and ground and final temperature. Our results show that this software (on both personal computer and Android platforms) is efficient and convenient to predict the heat collection rate and heat loss coefficient due to it slow root mean square errors in prediction. The software now can be downloaded from http://t.cn/RLPKF08.

  2. PERFORMANCE DETERIORATION OF THERMOSIPHON SOLAR FLAT PLATE WATER HEATER DUE TO SCALING

    Directory of Open Access Journals (Sweden)

    arunachala umesh chandavar

    2011-12-01

    Full Text Available 0 0 1 340 1943 International Islamic University 16 4 2279 14.0 Normal 0 false false false EN-US JA X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Times New Roman";} The performance of Flat plate Solar Water Heater deteriorates within five to twelve years of their installation due to factors related to manufacturing, operating conditions, lack of maintenance etc. Especially, problem due to scaling is significant as it is based on quality of water used. The remaining factors are system dependent and could be overcome by quality production. Software is developed by incorporating Hottel Whillier Bliss (H-W-B equation to ascertain the effect of scaling on system efficiency in case of thermosiphon system. In case of clean thermosiphon system, the instantaneous efficiency calculated at 1000 W/m2 radiation is 72 % and it drops to 46 % for 3.7 mm scale thickness. The mass flow rate is reduced by 90 % for 3.7 mm scale thickness. Whereas, the average temperature drop of water in the tank is not critical due to considerable heat content in water under severe scaled condition.  But practically in case of major scale growth, some of the risers are likely to get blocked completely which leads to negligible temperature rise in the tank. ABSTRAK: Prestasi plat rata pemanas air suria merosot selepas lima hingga dua belas tahun  pemasangannya disebabkan faktor-faktor yang berkaitan dengan pembuatannya, cara kendaliannya, kurangnya penyelenggaraan dan sebagainya.  Terutama sekali, masalah disebabkan scaling (tembunan endapan mineral perlu diambil berat kerana ianya bergantung kepada kualiti air yang digunakan. Faktor-faktor selebihya bersandarkan sistem dan ia

  3. TOWARDS A UTAUT-BASED MODEL FOR THE INTENTION TO USE SOLAR WATER HEATERS BY LIBYAN HOUSEHOLDS

    Directory of Open Access Journals (Sweden)

    Ahmed Mohamed Saleh

    2014-01-01

    Full Text Available Among the most fundamental features to ensure the success of a new technology introduction is citizen acceptance. Based on a unified model, called the Unified Theory of Adoption and Use of Technology (UTAUT, this paper provides new insights into predicting adoption and identifying of the factors that may prompt people to accept and use of Solar Water Heaters as a concrete step toward using Renewable Energy Resources, and offer guidelines for energy saving for the Libyan government and that will contribute to the economy of the country.

  4. Heat losses through pipe connections in hot water stores

    DEFF Research Database (Denmark)

    Andersen, Elsa; Fan, Jianhua; Furbo, Simon

    2007-01-01

    The heat loss from pipe connections at the top of hot water storage tanks with and without a heat trap is investigated theoretically and compared to similar experimental investigations. Computational Fluid Dynamics (CFD) is used for the theoretical analysis. The investigations show that the heat...... loss from an ideally insulated pipe connected to the top of a hot water tank is mainly due to a natural convection flow in the pipe, that the heat loss coefficient of pipes connected to the top of a hot water tank is high, and that a heat trap can reduce the heat loss coefficient significantly. Further...

  5. Solar system for domestic hot water and space heating

    Energy Technology Data Exchange (ETDEWEB)

    Weiss, W. [Arbeitsgemeinschaf Erneubare Energie, Gleisdorf (Austria)

    1997-12-31

    The solar thermal markets, different types of solar systems for hot water and space heating, the dimensioning and the components of solar heating systems, the properties of the systems are reviewed in this presentation

  6. Prototype solar heating and cooling systems, including potable hot water

    Science.gov (United States)

    Bloomquist, D.; Oonk, R. L.

    1977-01-01

    Progress made in the development, delivery, and support of two prototype solar heating and cooling systems including potable hot water is reported. The system consists of the following subsystems: collector, auxiliary heating, potable hot water, storage, control, transport, and government-furnished site data acquisition. A comparison of the proposed Solaron Heat Pump and Solar Desiccant Heating and Cooling Systems, installation drawings, data on the Akron House at Akron, Ohio, and other program activities are included.

  7. Solar hot water system installed at Las Vegas, Nevada

    Science.gov (United States)

    1981-01-01

    A solar energy hot water system installed in a motor inn at Las Vegas, Nevada is described. The inn is a three story building with a flat roof for installation of the solar panels. The system consists of 1,200 square feet of liquid flat plate collectors, a 2,500 gallon insulated vertical steel storage tank, two heat exchangers, and pumps and controls. The system was designed to supply approximately 74 percent of the total hot water load.

  8. Motel solar-hot-water system--Dallas, Texas

    Science.gov (United States)

    1981-01-01

    Report describes system which meets 64 percent of hot water requirements of 120 room motel. Key system components include 1,000 square foot, roof-mounted collector array, 1,000 gallon storage tank, tube-in-shell heat exchanger, and three domestic hot-water tanks. Report contains calibration instructions for differential temperature controllers, shutdown procedures, and operation guidelines, performance analysis, and manufacturers' maintenance literature.

  9. Domestic Hot Water Usage in Hotels; Tappvarmvattenanvaendning paa hotell

    Energy Technology Data Exchange (ETDEWEB)

    Petersson, Stefan; Werner, Sven [FVB Sverige AB, Vaesteraas (Sweden); Sandberg, Martin; Wahlstroem, Aasa [Swedish National Testing and Research Inst., Boraas (Sweden)

    2004-06-01

    Historically, design curves for domestic hot water, have been well sized and therefore also the components oversized. The Swedish district heating companies have noticed this and some companies replace large valves with customer-required valves, which give several advantages. There are several reasons why valves and heat exchangers can be customer-required and still the customers demand for hot water comfort can be fulfilled. The domestic hot water flow is composed, the taps are often short, large simultaneous taps are not very likely. Also, the dimensioning flows occur in the winter period, while the components are dimensioned for the summer case. The water pipes level off temporary temperature drops and the user seldom notices these because water with 55 deg C is not used in the tap. For residential buildings there are dimensioning recommendations on domestic hot water flow, but not for hotels. The purpose of this project has been to evaluate the domestic hot water use in relation to size and number of occupied beds. If the patterns of the chosen hotels coincide regarding to the sizes, dimensioning curves for domestic hot water use can be suggested. They can be used when hotels, or buildings with the same use pattern, are being built or restored. Measurements on 3 hotels with different sizes have been made. The hotels have 36, 52 and 158 rooms. The hotels are situated in the cities of Boraas and Kinna in Sweden. A short period of measurements from another hotel in the city of Gaevle (199 rooms) has also been included in this project. The measurements show that large hot water taps in hotels are rare and short. For the hotels, relative, cumulative relative frequencies and likely extreme values have been estimated. For residential buildings, The Swedish District Heating Association have recommendations for dimensioned domestic hot water flows. Formerly, these recommendations have been levelled so a cumulative relative frequency of 1 %, is reached, i.e. 99 % of all

  10. Hot spots and hot moments in riparian zones: Potential for improved water quality management

    Science.gov (United States)

    Philippe Vidon; Craig Allan; Douglas Burns; Tim P. Duval; Noel Gurwick; Shreeram Inamdar; Richard Lowrance; Judy Okay; Durelle Scott; Stephen Sebestyen

    2010-01-01

    Biogeochemical and hydrological processes in riparian zones regulate contaminant movement to receiving waters and often mitigate the impact of upland sources of contaminants on water quality. These heterogeneous processes have recently been conceptualized as "hot spots and moments" of retention, degradation, or production. Nevertheless, studies investigating...

  11. Interactive Effects of Corrosion, Copper, and Chloramines on Legionella and Mycobacteria in Hot Water Plumbing.

    Science.gov (United States)

    Rhoads, William J; Pruden, Amy; Edwards, Marc A

    2017-06-20

    Complexities associated with drinking water plumbing systems can result in undesirable interactions among plumbing components that undermine engineering controls for opportunistic pathogens (OPs). In this study, we examine the effects of plumbing system materials and two commonly applied disinfectants, copper and chloramines, on water chemistry and the growth of Legionella and mycobacteria across a transect of bench- and pilot-scale hot water experiments carried out with the same municipal water supply. We discovered that copper released from corrosion of plumbing materials can initiate evolution of >1100 times more hydrogen (H2) from water heater sacrificial anode rods than does presence of copper dosed as soluble cupric ions. H2 is a favorable electron donor for autotrophs and causes fixation of organic carbon that could serve as a nutrient for OPs. Dosed cupric ions acted as a disinfectant in stratified stagnant pipes, inhibiting culturable Legionella and biofilm formation, but promoted Legionella growth in pipes subject to convective mixing. This difference was presumably due to continuous delivery of nutrients to biofilm on the pipes under convective mixing conditions. Chloramines eliminated culturable Legionella and prevented L. pneumophila from recolonizing biofilms, but M. avium gene numbers increased by 0.14-0.76 logs in the bulk water and were unaffected in the biofilm. This study provides practical confirmation of past discrepancies in the literature regarding the variable effects of copper on Legionella growth, and confirms prior reports of trade-offs between Legionella and mycobacteria if chloramines are applied as secondary disinfectant residual.

  12. Hot water treatments delay cold-induced banana peel blackening

    NARCIS (Netherlands)

    Promyou, S.; Ketsa, S.; Doorn, van W.G.

    2008-01-01

    Banana fruit of cv. Gros Michel (Musa acuminata, AAA Group, locally called cv. Hom Thong) and cv. Namwa (Musa x paradisiaca, ABB Group) were immersed for 5, 10 and 15 min in water at 42 degrees C, or in water at 25 degrees C (control), and were then stored at 4 degrees C. Hot water treatment for 15

  13. Technical support document: Energy efficiency standards for consumer products: Room air conditioners, water heaters, direct heating equipment, mobile home furnaces, kitchen ranges and ovens, pool heaters, fluorescent lamp ballasts and television sets. Volume 1, Methodology

    Energy Technology Data Exchange (ETDEWEB)

    1993-11-01

    The Energy Policy and Conservation Act (P.L. 94-163), as amended, establishes energy conservation standards for 12 of the 13 types of consumer products specifically covered by the Act. The legislation requires the Department of Energy (DOE) to consider new or amended standards for these and other types of products at specified times. DOE is currently considering amending standards for seven types of products: water heaters, direct heating equipment, mobile home furnaces, pool heaters, room air conditioners, kitchen ranges and ovens (including microwave ovens), and fluorescent light ballasts and is considering establishing standards for television sets. This Technical Support Document presents the methodology, data, and results from the analysis of the energy and economic impacts of the proposed standards. This volume presents a general description of the analytic approach, including the structure of the major models.

  14. The efficiency of the heat pump water heater, during DHW tapping cycle

    Directory of Open Access Journals (Sweden)

    Gużda Arkadiusz

    2017-01-01

    Full Text Available This paper discusses one of the most effective systems for domestic hot water (DHW production based on air-source heat pump with an integrated tank. The operating principle of the heat pump is described in detail. Moreover, there is an account of experimental set-up and results of the measurements. In the experimental part, measurements were conducted with the aim of determining the energy parameters and measures of the economic efficiency related to the presented solution. The measurements that were conducted are based on the tapping cycle that is similar to the recommended one in EN-16147 standard. The efficiency of the air source heat pump during the duration of the experiment was 2.43. In the end of paper, authors conducted a simplified ecological analysis in order to determine the influence of operation of air-source heat pump with integrated tank on the environment. Moreover the compression with the different source of energy (gas boiler with closed combustion chamber and boiler fired by the coal was conducted. The heat pump is the ecological friendly source of the energy.

  15. The efficiency of the heat pump water heater, during DHW tapping cycle

    Science.gov (United States)

    Gużda, Arkadiusz; Szmolke, Norbert

    2017-10-01

    This paper discusses one of the most effective systems for domestic hot water (DHW) production based on air-source heat pump with an integrated tank. The operating principle of the heat pump is described in detail. Moreover, there is an account of experimental set-up and results of the measurements. In the experimental part, measurements were conducted with the aim of determining the energy parameters and measures of the economic efficiency related to the presented solution. The measurements that were conducted are based on the tapping cycle that is similar to the recommended one in EN-16147 standard. The efficiency of the air source heat pump during the duration of the experiment was 2.43. In the end of paper, authors conducted a simplified ecological analysis in order to determine the influence of operation of air-source heat pump with integrated tank on the environment. Moreover the compression with the different source of energy (gas boiler with closed combustion chamber and boiler fired by the coal) was conducted. The heat pump is the ecological friendly source of the energy.

  16. Co-Production Performance Evaluation of a Novel Solar Combi System for Simultaneous Pure Water and Hot Water Supply in Urban Households of UAE

    Directory of Open Access Journals (Sweden)

    Nutakki Tirumala Uday Kumar

    2017-04-01

    Full Text Available Water is the most desirable and sparse resource in Gulf cooperation council (GCC region. Utilization of point-of-use (POU water treatment devices has been gaining huge market recently due to increase in knowledge of urban population on health related issues over contaminants in decentralized water distribution networks. However, there is no foolproof way of knowing whether the treated water is free of contaminants harmful for drinking and hence reliance on certified bottled water has increased worldwide. The bottling process right from treatment to delivery is highly unsustainable due to huge energy demand along the supply chain. As a step towards sustainability, we investigated various ways of coupling of membrane distillation (MD process with solar domestic heaters for co-production of domestic heat and pure water. Performance dynamics of various integration techniques have been evaluated and appropriate configuration has been identified for real scale application. A solar combi MD (SCMD system is experimentally tested for single household application for production 20 L/day of pure water and 250 L/day of hot water simultaneously without any auxiliary heating device. The efficiency of co-production system is compared with individual operation of solar heaters and solar membrane distillation.

  17. Origin of life and living matter in hot mineral water

    OpenAIRE

    Ignatov, Ignat; Mosin, Oleg

    2013-01-01

    In this review the composition of water and isotopic structure of water during a process of origin of life is submitted. The data obtained testify that life maintenance depends on physical-chemical properties of water and external factors – temperature and рН. Hot mineral alkaline water, which interacts with CaCO 3 is closest to these conditions. Next in line with regard to quality is sea and mountain water.

  18. Smart solar tanks for small solar domestic hot water systems

    DEFF Research Database (Denmark)

    Furbo, Simon; Andersen, Elsa; Knudsen, Søren

    2005-01-01

    the hot-water tank from the top and the water volume heated by the auxiliary energy supply system is fitted to the hot-water consumption and consumption pattern. In periods with a large hot-water demand, the volume is large; in periods with a small hot-water demand, the volume is small. Two small SDHW......Investigation of small SDHW systems based on smart solar tanks are presented. The domestic water in a smart solar tank can be heated both by solar collectors and by means of an auxiliary energy supply system. The auxiliary energy supply system – in this study electric heating elements – heats up...... or small hot-water consumption and the risk of oversized solar heating systems and oversized tank volumes is reduced by using smart solar tanks. Based on the investigations it is recommended to start development of smart solar tank units with an oil-fired boiler or a natural gas burner as auxiliary energy...

  19. Energy Efficiency and Sustainability Evaluation of Space and Water Heating in Urban Residential Buildings of the Hot Summer and Cold Winter Zone in China

    Directory of Open Access Journals (Sweden)

    Xiao Chen

    2016-09-01

    Full Text Available With the urbanization process of the hot summer and cold winter (HSCW zone in China, the energy consumption of space and water heating in urban residential buildings of the HSCW zone has increased rapidly. This study presents the energy efficiency and sustainability evaluation of various ways of space and water heating taking 10 typical cities in the HSCW zone as research cases. Two indicators, primary energy efficiency (PEE and sustainability index based on exergy efficiency, are adopted to perform the evaluation. Models for the energy and total exergy efficiencies of various space and water heating equipment/systems are developed. The evaluation results indicate that common uses of electricity for space and water heating are the most unsustainable ways of space and water heating. In terms of PEE and sustainability index, air-source heat pumps for space and water heating are suitable for the HSCW zone. The PEE and sustainability index of solar water heaters with auxiliary electric heaters are greatly influenced by local solar resources. Air-source heat pump assisted solar hot water systems are the most sustainable among all water heating equipment/systems investigated in this study. Our works suggest the key potential for improving the energy efficiency and the sustainability of space and water heating in urban residential buildings of the HSCW zone.

  20. Statistical Modeling of Controllable Heat Pump Water Heaters Considering Customers' Convenience and Uncertainty and its Application to Frequency Control in Power System with a Large Penetration of Renewable Energy Sources

    Science.gov (United States)

    Masuta, Taisuke; Gunjikake, Yasutoshi; Yokoyama, Akihiko; Tada, Yasuyuki

    Nowadays, electric power systems confront many problems, such as environmental issues, aging infrastructures, energy security, and quality of electricity supply. The smart grid is a new concept of a better future grid, which enables us to solve the mentioned problems with Information and Communication Technology (ICT). In this research, a number of Heat Pump Water Heaters (HPWHs), one of the energy efficient-use customer equipment, and Battery Energy Storage System (BESS) are considered as controllable equipment for the frequency control. The utilization of customer equipment such as HPWH for power system control is one of the key elements in the concept of Ubiquitous Power Grid, which was proposed by our research group as a smart grid in Japanese context. The frequency control using a number of HPWHs with thermal storage of hot water tank is evaluated. Moreover, a novel statistical modeling of controllable HPWHs taking into account customers' convenience and uncertainty is proposed.

  1. Is hot water immersion an effective treatment for marine envenomation?

    Science.gov (United States)

    Atkinson, P R T; Boyle, A; Hartin, D; McAuley, D

    2006-01-01

    Envenomation by marine creatures is common. As more people dive and snorkel for leisure, the incidence of envenomation injuries presenting to emergency departments has increased. Although most serious envenomations occur in the temperate or tropical waters of the Indo‐Pacific region, North American and European waters also provide a habitat for many stinging creatures. Marine envenomations can be classified as either surface stings or puncture wounds. Antivenom is available for a limited number of specific marine creatures. Various other treatments such as vinegar, fig juice, boiled cactus, heated stones, hot urine, hot water, and ice have been proposed, although many have little scientific basis. The use of heat therapies, previously reserved for penetrating fish spine injuries, has been suggested as treatment for an increasing variety of marine envenomation. This paper reviews the evidence for the effectiveness of hot water immersion (HWI) and other heat therapies in the management of patients presenting with pain due to marine envenomation. PMID:16794088

  2. Retrofitted Solar Domestic Hot Water Systems for Swedish Single-Family Houses—Evaluation of a Prototype and Life-Cycle Cost Analysis

    Directory of Open Access Journals (Sweden)

    Luis Ricardo Bernardo

    2016-11-01

    Full Text Available According to recent technology road maps, system cost reductions and development of standardised plug-and-function systems are some of the most important goals for solar heating technology development. Retrofitting hot water boilers in single-family houses when installing solar collectors has the potential to significantly reduce both material and installation costs. Previous studies have investigated such retrofitting, using theoretical simulations and laboratory tests, but no actual installations were made and tested in practice. This article describes the installation, measured performance and cost effectiveness of a retrofitting solution that converts existing domestic hot water heaters to a solar domestic hot water system. The measured performance is characterised by the monthly and annual solar fractions. The cost effectiveness is evaluated by a life-cycle cost analysis, comparing the retrofitted system to a conventional solar domestic hot water system and the case without any solar heating system. Measurements showed that approximately 50% of the 5000 kWh/year of domestic hot water consumption was saved by the retrofitted system in south Sweden. Such savings are in agreement with previous estimations and are comparable to the energy savings when using a conventional solar domestic hot water system. The life-cycle cost analysis showed that, according to the assumptions and given climate, the return on investment of the retrofitted system is approximately 17 years, while a conventional system does not reach profitability during its lifetime of 25 years.

  3. An analysis on Free Convection Cooling of a 3×3 Heater Array in Rectangular Enclosure using Cu-EG-Water Nanofluid

    OpenAIRE

    Abimanyu Purusothaman; Venkatachalam Divya; Nagarajan Nithyadevi; ÖZTOP, H. F.

    2016-01-01

    This paper deals with the study of natural convection cooling of a discrete heater array in Cu-EG-water nanofluid filled rectangular enclosure. A 3 × 3 array of non-protruding heat sources is embedded on one of the vertical walls of the enclosure while the top horizontal and opposite vertical walls are assumed to be isothermally cold. The remaining portions in which the heaters are mounted and all other walls are insulated. The above setup is modeled into a system of partial differential equa...

  4. Application of CAE-modeling for the study of the influence of the sensor location on the flow-through water heater operation

    Science.gov (United States)

    Yakunin, A. G.

    2018-01-01

    The article deals with issues related to increasing the efficiency of the system of automatic maintenance of the temperature of liquid media entering the pipes to the place of consumption. For this purpose, a flowing water heater model is proposed, made in the SolidWorks environment, the construction parameters of which can be changed using the appropriate macro and screen form. It is shown that the choice of the location of the temperature sensor has a significant effect on such parameters of the device as the accuracy of maintaining a given temperature regime and the duration of the transient process caused by a change in the temperature of the liquid entering the heater. On a concrete example, it is shown that by changing the distance between the sensor and the heating module, it is possible to achieve minimum temperature fluctuations of the heat-transfer-agent at the heater outlet.

  5. Investigation on Kombiterm GE Domestic Hot Water Tank

    DEFF Research Database (Denmark)

    Heller, Alfred; Heuer, Andreas Walter

    1996-01-01

    Investigation of a hot water tank with a high heat exchanger spiral with a small pipe diameter in the upper part of the heat exchanger spiral and a large pipe diameter in the lower part of the heat exchanger spiral in cooperation with Kãhler&Breum Beholder- og Maskinfabrik K/S. First preprint of ...... of project resulting in final "Sagsrapport": Andreas Heuer, "High Spiral Heat Exchanger in Domestic Hot Water Tanks.", SR-9711, 1997, ISSN 1396-402X.Andreas Heuer, "User Manual for Simulation Program GETANK", SR-9712, 1997, ISSN1396-402X.......Investigation of a hot water tank with a high heat exchanger spiral with a small pipe diameter in the upper part of the heat exchanger spiral and a large pipe diameter in the lower part of the heat exchanger spiral in cooperation with Kãhler&Breum Beholder- og Maskinfabrik K/S. First preprint...

  6. LWRS Fuels Pathway: Engineering Design and Fuels Pathway Initial Testing of the Hot Water Corrosion System

    Energy Technology Data Exchange (ETDEWEB)

    Dr. John Garnier; Dr. Kevin McHugh

    2012-09-01

    The Advanced LWR Nuclear Fuel Development R&D pathway performs strategic research focused on cladding designs leading to improved reactor core economics and safety margins. The research performed is to demonstrate the nuclear fuel technology advancements while satisfying safety and regulatory limits. These goals are met through rigorous testing and analysis. The nuclear fuel technology developed will assist in moving existing nuclear fuel technology to an improved level that would not be practical by industry acting independently. Strategic mission goals are to improve the scientific knowledge basis for understanding and predicting fundamental nuclear fuel and cladding performance in nuclear power plants, and to apply this information in the development of high-performance, high burn-up fuels. These will result in improved safety, cladding, integrity, and nuclear fuel cycle economics. To achieve these goals various methods for non-irradiated characterization testing of advanced cladding systems are needed. One such new test system is the Hot Water Corrosion System (HWCS) designed to develop new data for cladding performance assessment and material behavior under simulated off-normal reactor conditions. The HWCS is capable of exposing prototype rodlets to heated, high velocity water at elevated pressure for long periods of time (days, weeks, months). Water chemistry (dissolved oxygen, conductivity and pH) is continuously monitored. In addition, internal rodlet heaters inserted into cladding tubes are used to evaluate repeated thermal stressing and heat transfer characteristics of the prototype rodlets. In summary, the HWCS provides rapid ex-reactor evaluation of cladding designs in normal (flowing hot water) and off-normal (induced cladding stress), enabling engineering and manufacturing improvements to cladding designs before initiation of the more expensive and time consuming in-reactor irradiation testing.

  7. The effect of hot water injection on sandstone permeability

    DEFF Research Database (Denmark)

    Rosenbrand, Esther; Haugwitz, Christian; Jacobsen, Peter Sally Munch

    2014-01-01

    Seasonal energy storage can be achieved by hot water injection in geothermal sandstone aquifers. We present an analysis of literature data in combination with new short-term flow through permeability experiments in order to address physical and physico-chemical mechanisms that can alter permeabil......Seasonal energy storage can be achieved by hot water injection in geothermal sandstone aquifers. We present an analysis of literature data in combination with new short-term flow through permeability experiments in order to address physical and physico-chemical mechanisms that can alter...

  8. Hot Water Epilepsy Successfully Treated With Daily Clobazam.

    Science.gov (United States)

    Ekici, Arzu; Ozdemir, Ozlem; Yimenicioglu, Sevgi; Oren, Ayse; Sen, Ismail

    2017-10-01

    Hot water epilepsy (HWE) is a rare form of reflex epilepsy precipitated by a bath or shower in hot water. Although the condition is benign and a decreased bath temperature will help, antiepileptic drugs may be needed in some cases. Prophylactic clobazam is currently the first choice treatment option. Here we report the case of a 10-year-old boy with HWE successfully treated with daily doses of clobazam. Daily clobazam was preferred over prophylactic clobazam because of the patient's frequent bathing and parental concern. Daily clobazam is a novel treatment option for HWE and seems to be a good choice where antiepileptic drugs are necessary.

  9. Thermodynamic Analysis of a Steam Power Plant with Double Reheat and Feed Water Heaters

    Directory of Open Access Journals (Sweden)

    M. M. Rashidi

    2014-03-01

    Full Text Available A steam cycle with double reheat and turbine extraction is presented. Six heaters are used, three of them at high pressure and the other three at low pressure with deaerator. The first and second law analysis for the cycle and optimization of the thermal and exergy efficiencies are investigated. An exergy analysis is performed to guide the thermodynamic improvement for this cycle. The exergy and irreversibility analyses of each component of the cycle are determined. Effects of turbine inlet pressure, boiler exit steam temperature, and condenser pressure on the first and second laws' efficiencies are investigated. Also the best turbine extraction pressure on the first law efficiency is obtained. The results show that the biggest exergy loss occurs in the boiler followed by the turbine. The results also show that the overall thermal efficiency and the second law efficiency decrease as the condenser pressure increases for any fixed outlet boiler temperature, however, they increase as the boiler temperature increases for any condenser pressure. Furthermore, the best values of extraction pressure from high, intermediate, and low pressure turbine which give the maximum first law efficiencies are obtained based on the required heat load corresponding to each exit boiler temperature.

  10. Self-construction of a solar water heater; Calentador solar de agua de auto-construccion

    Energy Technology Data Exchange (ETDEWEB)

    Lentz Herrera, Alvaro E.; Rincon Mejia, Eduardo A. [Universidad Autonoma de la Ciudad de Mexico, Mexico, D.F. (Mexico)

    2009-07-01

    In this work a flat receiver of self construction is shown with relatively low cost and easy manufacture, but with a thermal efficiency superior to 40% for applications at temperatures less than 60 degrees Celsius, that allows satisfying international standards in this respect. The heater has been matter of study in open courses distributed in the Universidad Autonoma de la Ciudad de Mexico (UACM) oriented to that the participants construct their own system, in addition to its installation and tests. The obtained results have been excellent. The massive use of efficient solar receivers of self-construction can truly help to the decreasing of the gas discharges of greenhouse effect. [Spanish] En este trabajo se presenta un captador plano de auto construccion con relativamente bajo costo y facil manufactura, pero con un rendimiento termico superior a 40% para aplicaciones a temperatura menos de 60 grados centigrados que le permite satisfacer estandares internacionales a este respecto. El calentador ha sido materia de estudio en cursos abiertos impartidos en la Universidad Autonoma de la Ciudad de Mexico (UACM) orientados a que los participantes construyan su propio sistema, ademas de su instalacion y pruebas. Los resultados obtenidos han sido excelentes. El uso masivo de captadores solares eficientes de autoconstruccion puede en verdad coadyuvar a la disminucion de las emisiones de gases de efecto invernadero.

  11. Pouring 'Cold Water' on Hot Accretion

    Science.gov (United States)

    Rubin, A. E.

    1995-09-01

    The extensive recrystallization of type-6 OC has been interpreted as having resulted either from prograde thermal metamorphism of initially cold, unequilibrated material [1,2] or from autometamorphism due to slow cooling of material that accreted while still hot (1000-1200 K). Although the physical implausibility of hot accretion has been addressed [3], no comprehensive evaluation has been made of arguments in its favor. As shown below, these arguments are based on incomplete data, flawed experiments or improbable interpretations. Correlation between petrologic type and Ca in low-Ca pyroxene. Models of prograde metamorphism assume that, with increasing temperature, opx acquires Ca at the expense of diopside. Analyses of pyroxene in 10 H chondrites showed no correlation between Ca in pyroxene cores and increasing petrologic type [4], but more extensive data sets show such correlations [1,5,6]. A review of data for 51 OC [7] shows a progressive increase in the Wo content of low-Ca pyroxene with petrologic type: Wo 0.4-1.2 in type-3 and -4; Wo 1.2-1.6 in type-5; and Wo 1.6-2.2 in type-6. Striated opx. Undeformed striated opx were interpreted as having formed from inverted protopyroxene during slow cooling [8]; striated opx from H4 Quenggouk were found to convert into normal opx within 1 week during annealing at 1100 K [9]. Because prograde metamorphism probably lasted ~60 Ma [10], there should be no striated opx remaining in type-4 or -5 OC. However, samples of 99% twinned clinopyroxene (analogous to that in chondrules in type-3 OC) annealed for >3 weeks at Conquista could not have formed during single stage cooling as expected in autometamorphism; a two-stage cooling history involving rapid cooling during chondrule formation followed by parent-body annealing is more plausible. Polycrystalline taenite. Polycrystalline taenite in H/L3 Tieschitz was interpreted as a relict solidification structure that failed to anneal into monocrystalline taenite because of rapid

  12. Extreme learning machine: a new alternative for measuring heat collection rate and heat loss coefficient of water-in-glass evacuated tube solar water heaters.

    Science.gov (United States)

    Liu, Zhijian; Li, Hao; Tang, Xindong; Zhang, Xinyu; Lin, Fan; Cheng, Kewei

    2016-01-01

    Heat collection rate and heat loss coefficient are crucial indicators for the evaluation of in service water-in-glass evacuated tube solar water heaters. However, the direct determination requires complex detection devices and a series of standard experiments, wasting too much time and manpower. To address this problem, we previously used artificial neural networks and support vector machine to develop precise knowledge-based models for predicting the heat collection rates and heat loss coefficients of water-in-glass evacuated tube solar water heaters, setting the properties measured by "portable test instruments" as the independent variables. A robust software for determination was also developed. However, in previous results, the prediction accuracy of heat loss coefficients can still be improved compared to those of heat collection rates. Also, in practical applications, even a small reduction in root mean square errors (RMSEs) can sometimes significantly improve the evaluation and business processes. As a further study, in this short report, we show that using a novel and fast machine learning algorithm-extreme learning machine can generate better predicted results for heat loss coefficient, which reduces the average RMSEs to 0.67 in testing.

  13. Solar Hot Water Heating by Natural Convection.

    Science.gov (United States)

    Noble, Richard D.

    1983-01-01

    Presents an undergraduate laboratory experiment in which a solar collector is used to heat water for domestic use. The working fluid is moved by natural convection so no pumps are required. Experimental apparatus is simple in design and operation so that data can be collected quickly and easily. (Author/JN)

  14. Effects of sulphuric acid and hot water treatments on seed ...

    African Journals Online (AJOL)

    A study was carried out to investigate the effects of sulphuric acid and hot water treatments on the germination of Tamarind (Tamarindus indica L). Seeds were placed on moistened filter papers in 28 cm diameter Petri dishes under laboratory condition for germination. 330 seeds of T. indica (10 seeds per Petri dish) with ...

  15. Temperature stratification in a hot water tank with circulation pipe

    DEFF Research Database (Denmark)

    Andersen, Elsa

    1998-01-01

    The aim of the project is to investigate the change in temperature stratification due to the operation of a circulation pipe. Further, putting forward rules for design of pipe inlet in order not to disturb the temperature stratification in the hot water tank. A validated computer model based...

  16. Design and installation package for solar hot water system

    Energy Technology Data Exchange (ETDEWEB)

    1978-12-01

    This report contains the design and installation procedure for the Solar Engineering and Manufacturing Company's solar hot water system. Included are the system performance specifications, system design drawings, hazard analysis and other information necessary to evaluate the design and instal the system.

  17. Effects of Hot Water Treatment and Temperature on Seedling ...

    African Journals Online (AJOL)

    An experiment was conducted at the Faculty of Agriculture, University of Maiduguri, to study the effect of hot water treatment and temperature on the morphological characteristics of Arabic gum. The experiment was laid out in a Randomized Complete Block Design in a factorial arrangement. The treatments included a ...

  18. 207 EFFECTS OF HOT AND COLD WATER PRE- TREATMENTS ...

    African Journals Online (AJOL)

    temperature) for 8, 12 and 24 hours and hot water at 100 C for 5, 10 and 15 minutes . The research seeks to find the best pre germination time to be used for each of the two pre- treatments used in the experiment. Completely randomized design (CRD) of analysis of variance (ANOVA) was used in analysis of obtained data ...

  19. Metagenomic analysis of bacterial diversity of Siloam hot water ...

    African Journals Online (AJOL)

    The bacterial diversity of Siloam hot water spring was determined using 454 pyrosequencing of two 16S rRNA variable regions V1-3 and V4-7. Analysis of the community DNA revealed that the phyla Proteobacteria, Cyanobacteria, Bacteriodetes, Planctomycetes, Firmicutes, Chloroflexi and Verrucomicrobia were the most ...

  20. Microbial induced corrosion (MIC) on DHP copper by Desulfovibrio desulfuricans and Bacillus megaterium strains in media simulating heater waters

    Energy Technology Data Exchange (ETDEWEB)

    Zumelzu, E.; Cabezas, C.; Schoebitz, R.; Ugarte, R.; Rodriguez, E.D.; Rios, J. [Universidad Austral de Chile, Valdivia (Chile)

    2003-01-01

    The complexity and diversity of microbial populations in water heating systems of steam generators make it necessary to study the magnitude of the metabolic activity of bacteria and biofilm development that may lead to degradation of metal components through microbial induced corrosion (MIC). Electrolytes simulating the conditions found in heater water networks were used to induce biofilm formation on DHP copper coupons by Desulfovibrio desulfuricans DSMZ and Bacillus megaterium C10, a commercial strain and an isolate from these waters, respectively. In order to enhance their action, industrial waters enriched with the minimum nutrient content such as sodium lactate and sodium sulphite for the DSMZ strain and glucose, proteose peptone and starch for the C10 strain were employed. Biofilm formation was studied under controlled temperature, time, shaking, pH and concentrations of the media used in this study. Then, the samples were electrochemically tested in an artificial solution of sea water as control medium, based on the hypothesis that the action of an aggressive biofilm/electrolyte medium generates damaged and non-damaged areas on the metal surface, and assuming that the sea water trial can detect the latter. Hence, a higher anodic current was associated with a lower degradation of the metal surface by the action of one of the media under study. All these trials were performed along with bacterial count, scanning electron microscopy (SEM) and atomic absorption spectroscopy (AAS). Furthermore, it was possible to identify under which conditions MIC on DHP copper occurred and complex mechanisms from retention of cations to diffusion processes at the biofilm/tested media interface level were proposed. Surface corrosion by MIC took place on DHP copper; therefore, greater control on the treatment of industrial waters is highly desirable. (author)

  1. Corrosion of galvanized pipes in the hot water supply system

    Directory of Open Access Journals (Sweden)

    Andrianov Alexey

    2017-01-01

    Full Text Available The paper describes the problem of steel pipes corrosion in domestic hot water supply systems. A case study of abnormally high rate of corrosion of galvanized steel pipes in a hot water supply system, installed in a complex of residential and public buildings, was considered. The rapid corrosion led to premature failure of these pipelines. Onsite visual inspection, chemical analysis of the tap water with LSI/RSI calculation and scanning electron microscopy and energy-dispersive X-ray spectroscopy analysis were used during this study. The basic factors that lead to pitting corrosion were established: quality of source water (its high corrosion activity, high temperature and local increase in oxygen content near the pipe surface. A possibility of microbial corrosion was also assumed.

  2. Investigation of the heat pump water heater using economizer vapor injection system and mixture of R22/R600a

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Cao; Kai, Wang; Shouguo, Wang; Ziwen, Xing; Pengcheng, Shu [School of Energy and Power Engineering, Xi' an Jiaotong University, 28 Xianing west road, Xi' an 710049 (China)

    2009-05-15

    This paper presents the experimental study of a heat pump water heater (HPWH) using economizer vapor injection system and mixture of R22/R600a. Performances of HPWH using economizer vapor injection system are compared with that at different mixed mass ratios of R22/R600a. Study demonstrates that the heating capacity and energy efficiency ratio (EER) of the unit increased, and the discharge temperature of compressor decreased when using vapor injection and mixing refrigerant of R22/R600a. It is also found that the HPWH unit with economizer vapor injection system has a better performance for the high outlet water temperature under lower temperature conditions at 15% mass ratio of R600a for the mixing refrigerant. In addition, fundamental and practical influence of vapor injection pressure on the HPWH performance has been investigated experimentally. The simplified model is proposed for predicting the optimal vapor injection pressure of compressor using the mixing refrigerant R22/R600a. (author)

  3. 46 CFR 63.25-3 - Electric hot water supply boilers.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Electric hot water supply boilers. 63.25-3 Section 63.25... water supply boilers. (a) Electric hot water supply boilers that have a capacity not greater than 454... section except the periodic testing required by paragraph (j) of this section. Electric hot water supply...

  4. Energy efficiency of a solar domestic hot water system

    Science.gov (United States)

    Zukowski, Miroslaw

    2017-11-01

    The solar domestic hot water (SDHW) system located on the campus of Bialystok University of Technology is the object of the research described in the current paper. The solar thermal system is composed of 35 flat plate collectors, 21 evacuated tube collectors and eight hot water tanks with the capacity of 1 m3 of each. Solar facility is equipped with hardware for automatic data collection. Additionally, the weather station located on the roof of the building provides measurements of basic parameters of ambient air and solar radiation. The main objective of Regional Operational Program was the assessment of the effectiveness of this solar energy technology in the climatic conditions of the north-eastern Poland. Energy efficiency of SDHW system was defined in this research as the ratio between the useful heat energy supplied to the domestic hot water system and solar energy incident on the surface of solar panels. Heat loss from water storage tanks, and from the pipe network to the surrounding air, as well as the electrical energy consumed by the pumps have been included in the calculations. The paper presents the detailed results and conclusions obtained from this energy analysis.

  5. Thermomechanical finite element analysis of hot water boiler structure

    Directory of Open Access Journals (Sweden)

    Živković Dragoljub S.

    2012-01-01

    Full Text Available The paper presents an application of the Finite Elements Method for stress and strain analysis of the hot water boiler structure. The aim of the research was to investigate the influence of the boiler scale on the thermal stresses and strains of the structure of hot water boilers. Results show that maximum thermal stresses appear in the zone of the pipe carrying wall of the first reversing chamber. This indicates that the most critical part of the boiler are weld spots of the smoke pipes and pipe carrying plate, which in the case of significant scale deposits can lead to cracks in the welds and water leakage from the boiler. The nonlinear effects were taken into account by defining the bilinear isotropic hardening model for all boiler elements. Temperature dependency was defined for all relevant material properties, i. e. isotropic coefficient of thermal expansion, Young’s modulus, and isotropic thermal conductivity. The verification of the FEA model was performed by comparing the measured deformations of the hot water boiler with the simulation results. As a reference object, a Viessmann - Vitomax 200 HW boiler was used, with the installed power of 18.2 MW. CAD modeling was done within the Autodesk Inventor, and stress and strain analysis was performed in the ANSYS Software.

  6. Energy efficiency of a solar domestic hot water system

    Directory of Open Access Journals (Sweden)

    Zukowski Miroslaw

    2017-01-01

    Full Text Available The solar domestic hot water (SDHW system located on the campus of Bialystok University of Technology is the object of the research described in the current paper. The solar thermal system is composed of 35 flat plate collectors, 21 evacuated tube collectors and eight hot water tanks with the capacity of 1 m3 of each. Solar facility is equipped with hardware for automatic data collection. Additionally, the weather station located on the roof of the building provides measurements of basic parameters of ambient air and solar radiation. The main objective of Regional Operational Program was the assessment of the effectiveness of this solar energy technology in the climatic conditions of the north-eastern Poland. Energy efficiency of SDHW system was defined in this research as the ratio between the useful heat energy supplied to the domestic hot water system and solar energy incident on the surface of solar panels. Heat loss from water storage tanks, and from the pipe network to the surrounding air, as well as the electrical energy consumed by the pumps have been included in the calculations. The paper presents the detailed results and conclusions obtained from this energy analysis.

  7. Determination of inorganic compounds in drinking water on the basis of house water heater scale, part 1: Determination of heavy metals and uranium

    Directory of Open Access Journals (Sweden)

    Rajković Miloš B.

    2004-01-01

    Full Text Available The analysis of scale originated from drinking water on the house water heater, showed that scale is basically calcium carbonate that crystallizes hexagonally in the form of calcite. Scale taken as a sample from different spots in Belgrade – upper town of Zemun (sample 1 and Pančevo (sample 2 showed different configuration although it came from the same waterworks. That indicates either that the water flowing through waterworks pipes in different parts of the city is not the same or the waterworks net is not the same (age, maintaining, etc. All the elements which are dominant in drinking water (Ca, Mg, K, and Na, and which could be found in water by natural processes, are by their content far below the values regulated by law. The analysis also showed the presence of many metals: Ti, Pb, Zn, Cu Li, Sr, Cd, and Cr in the first sample, which are not found in the scale taken near Pančevo. The results obtained by calculating the mass concentration in drinking water on the basis of scale content, showed that both waters belonged to the category of low mineral waters. Contents of inorganic substances in these waters (117.85 mg/dm3 for sample 1 or 80.83 mg/dm3 for sample 2 are twice lower than the values predicted by the legislation. Gammaspectrometric analysis indicates the presence of radioactive elements – uranium and strontium which can influence human health.

  8. Overheating in Hot Water- and Steam-Heated Multifamily Buildings

    Energy Technology Data Exchange (ETDEWEB)

    Dentz, J.; Varshney, K.; Henderson, H.

    2013-10-01

    Apartment temperature data have been collected from the archives of companies that provide energy management systems (EMS) to multifamily buildings in the Northeast U.S. The data have been analyzed from more than 100 apartments in eighteen buildings where EMS systems were already installed to quantify the degree of overheating. This research attempts to answer the question, 'What is the magnitude of apartment overheating in multifamily buildings with central hot water or steam heat?' This report provides valuable information to researchers, utility program managers and building owners interested in controlling heating energy waste and improving resident comfort. Apartment temperature data were analyzed for deviation from a 70 degrees F desired setpoint and for variation by heating system type, apartment floor level and ambient conditions. The data shows that overheating is significant in these multifamily buildings with both hot water and steam heating systems.

  9. Investigations on stratification devices for hot water stores

    DEFF Research Database (Denmark)

    Andersen, Elsa; Furbo, Simon; Hampel, Matthias

    2008-01-01

    The significance of the thermal stratification for the energy efficiency of small solar-thermal hot water heat stores is pointed out. Exemplary the thermal stratification build-up with devices already marketed as well as with devices still in development has been investigated experimentally...... and theoretically, taking into account different realistic operation conditions. The methods (selective temperature measurement, non-invasive field measuring methods PIV and LIF, Computational Fluid Dynamics (CFD)) suitable for the experimental and theoretical analysis of thermal stratification devices...

  10. An unusual burn caused by hot argy wormwood leaf water

    Directory of Open Access Journals (Sweden)

    Feng Guo

    2011-09-01

    Full Text Available An unusual burn case caused by hot wormwood leaf water was discussed. A 29-year-old woman sustained a 7% second-degree burn on both buttocks and left thigh. This case report highlights a rare cause of a chemical burn that may become more common with increasing use of this Chinese traditional medicine. The prevention measures of this burn injury were also presented.

  11. Demonstration of domestic hot water with combination of wood stove hot water (winter) and homemade solar collector (summer). Final project report

    Energy Technology Data Exchange (ETDEWEB)

    Nichols, N.S. II

    1981-09-03

    The purpose of this project was to demonstrate that adequate hot water can be provided for a family of four in northeastern Pennsylvania, by using a combination of wood stove hot water in the winter and solar collector hot water during the non-heating months. This demonstration would be to encourage other people in the area to investigate using similar energy-saving systems, by providing an observable operating installation, and by increasing their confidence in using simple alternate-energy sources.

  12. Solar air heaters and their applications

    Science.gov (United States)

    Selcuk, M. K.

    1977-01-01

    The solar air heater appears to be the most logical choice, as far as the ultimate application of heating air to maintain a comfortable environment is concerned. One disadvantage of solar air heaters is the need for handling larger volumes of air than liquids due to the low density of air as a working substance. Another disadvantage is the low thermal capacity of air. In cases where thermal storage is needed, water is superior to air. Design variations of solar air heaters are discussed along with the calculation of the efficiency of a flat plate solar air heater, the performance of various collector types, and the applications of solar air heaters. Attention is given to collectors with nonporous absorber plates, collectors with porous absorbers, the performance of flat plate collectors with finned absorbers, a wire mesh absorber, and an overlapped glass plate air heater.

  13. 10 CFR 431.107 - Uniform test method for the measurement of energy efficiency of commercial heat pump water...

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 3 2010-01-01 2010-01-01 false Uniform test method for the measurement of energy efficiency of commercial heat pump water heaters. 431.107 Section 431.107 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY PROGRAM FOR CERTAIN COMMERCIAL AND INDUSTRIAL EQUIPMENT Commercial Water Heaters, Hot Water Supply Boilers and Unfire...

  14. Solar Energy in China: Development Trends for Solar Water Heaters and Photovoltaics in the Urban Environment

    Science.gov (United States)

    Wallace, William; Wang, Zhongying

    2006-01-01

    China is the world's largest market for solar water heating systems, installing 13 million square meters of new systems in 2004, mostly in large cities. Municipal authorities, however, are sensitive to quality and visual impact issues created by this technology deployment. Therefore, there is currently a trend toward developing building integrated…

  15. Volume reduction of Clark hot water extraction fine tailings

    Energy Technology Data Exchange (ETDEWEB)

    Sheeran, E. D. [ed.

    1995-06-01

    The principal focus of this volume is the reduction or elimination of the accumulation of fine tailings produced by the Clark Hot Water Extraction (CHWE) process, the process which is currently employed by commercial oil sands extraction operations in Alberta. Several opportunities in the process where reduction of fine tailings accumulation might be accomplished through either chemical or mechanical modifications, have been examined. Among these are: (1) selective mining, (2) alternate extraction processes, (3) prevention of segregation of coarse and fine tailings, (4) recombination of extraction tailings and fine tailings, (5) extraction of water from mature tailings, and (6) stabilization of mature fine tailings. 77 refs., tabs., figs.

  16. Concrete Carbonation and Chloride Resistance Under Initial Hot Water Curing

    OpenAIRE

    Li, Guo; Li, Xiaoling L.; Wei, Rongrong R.; Du, Jianmin M.; Wu, Xiaosuo S.

    2014-01-01

    Three concrete mix proportions were designed and prepared, respectively, such as fly ash concrete (abbreviated as “FAC”) with 30% fly ash replacement ratio of cement, fly ash, and slag concrete (abbreviated as “FSC”) with each of 20% fly ash and slag replacement ratio and ordinary Portland cement concrete (abbreviated as “OPC”) for the research of carbonation and chloride resistance of concrete under different initial hot water curing. Specimens with precuring were put into 20°C water tank fo...

  17. How to repel hot water from a superhydrophobic surface?

    KAUST Repository

    Yu, Zhejun

    2014-01-01

    Superhydrophobic surfaces, with water contact angles greater than 150° and slide angles less than 10°, have attracted a great deal of attention due to their self-cleaning ability and excellent water-repellency. It is commonly accepted that a superhydrophobic surface loses its superhydrophobicity in contact with water hotter than 50 °C. Such a phenomenon was recently demonstrated by Liu et al. [J. Mater. Chem., 2009, 19, 5602], using both natural lotus leaf and artificial leaf-like surfaces. However, our work has shown that superhydrophobic surfaces maintained their superhydrophobicity, even in water at 80 °C, provided that the leaf temperature is greater than that of the water droplet. In this paper, we report on the wettability of water droplets on superhydrophobic thin films, as a function of both their temperatures. The results have shown that both the water contact and slide angles on the surfaces will remain unchanged when the temperature of the water droplet is greater than that of the surface. The water contact angle, or the slide angle, will decrease or increase, however, with droplet temperatures increasingly greater than that of the surfaces. We propose that, in such cases, the loss of superhydrophobicity of the surfaces is caused by evaporation of the hot water molecules and their condensation on the cooler surface. © 2014 the Partner Organisations.

  18. Occurrence of Legionella in hot water systems of single-family residences in suburbs of two German cities with special reference to solar and district heating.

    Science.gov (United States)

    Mathys, Werner; Stanke, Juliane; Harmuth, Margarita; Junge-Mathys, Elisabeth

    2008-03-01

    A total of 452 samples from hot water systems of randomly selected single family residences in the suburbs of two German cities were analysed for the occurrence of Legionella. Technical data were documented using a standardized questionnaire to evaluate possible factors promoting the growth of the bacterium in these small plumbing systems. All houses were supplied with treated groundwater from public water works. Drinking water quality was within the limits specified in the German regulations for drinking water and the water was not chlorinated. The results showed that plumbing systems in private houses that provided hot water from instantaneous water heaters were free of Legionella compared with a prevalence of 12% in houses with storage tanks and recirculating hot water where maximum counts of Legionella reached 100,000 CFU/100ml. The presence of L. pneumophila accounted for 93.9% of all Legionella positive specimens of which 71.8% belonged to serogroup 1. The volume of the storage tank, interrupting circulation for several hours daily and intermittently raising hot water temperatures to >60 degrees C had no influence on Legionella counts. Plumbing systems with copper pipes were more frequently contaminated than those made of synthetic materials or galvanized steel. An inhibitory effect due to copper was not present. Newly constructed systems (district heating systems were colonized by Legionella. Their significantly lower hot water temperature is thought to be the key factor leading to intensified growth of Legionella. Although hot water systems using solar energy to supplement conventional hot water supplies operate at temperatures 3 degrees C lower than conventional systems, this technique does not seem to promote proliferation of the bacterium. Our data show convincingly that the temperature of the hot water is probably the most important or perhaps the only determinant factor for multiplication of Legionella. Water with a temperature below 46 degrees C was

  19. PERFORMANCE CHARACTERISTICS OF PARABOLIC SOLAR COLLECTOR WATER HEATER SYSTEM FITTED WITH NAIL TWISTED TAPES ABSORBER

    Directory of Open Access Journals (Sweden)

    K. SYED JAFAR

    2017-03-01

    Full Text Available In this paper, the experimental heat transfer, friction loss and thermal performance data for water flowing through the absorber tube fitted with two different twisted tape configurations in parabolic trough collector (PTC are presented. In the present work, a relative experimental study is carried out to investigate the performance of a PTC influenced by heat transfer through fluidabsorber wall mixing mechanism. The major findings of this experiment show that heat transport enhancement in the nail twisted tape collector perform significantly better than plain twisted tapes and also show that the smallest twisted tape ratio enhances the system performance remarkably maximizing the collector efficiency. The results suggest that the twisted tape and nail twisted tape would be a better option for high thermal energy collection in laminar region of the PTC system.

  20. Comparison of two temperature control techniques in a forced water heater solar system

    Science.gov (United States)

    Hernández, E.; E Guzmán, R.; Santos, A.; Cordoba, E.

    2017-12-01

    a study on the performance of a forced solar heating system in which a comparative analysis of two control strategies, including the classic on-off control and PID control is presented. From the experimental results it was found that the two control strategies show a similar behaviour in the solar heating system forced an approximate settling time of 60 min and over-elongation 2°C for the two control strategies. Furthermore, the maximum temperature in the storage tank was 46°C and the maximum efficiency of flat plate collector was 76.7% given that this efficiency is the ratio of the energy of the radiation on the collector and the energy used to heat water. The efficiency obtained is a fact well accepted because the business efficiencies of flat plate collectors are approximately 70%.

  1. Greenhouse Heater Checklist

    OpenAIRE

    Mullins, Chris

    2009-01-01

    Provides a maintenance checklist for unit heaters or forced air heaters in greenhouses to ensure the system is in good repair and operating condition, important for lessening the chance of ethylene exposure, reducing operating costs, and prolonging the life of the heater unit.

  2. Effect Of Hot Water Injection On Sandstone Permeability

    DEFF Research Database (Denmark)

    Rosenbrand, Esther; Fabricius, Ida Lykke

    2012-01-01

    The seasonal imbalance between supply and demand of renewable energy requires temporary storage, which can be achieved by hot water injection in warm aquifers. This requires that the permeability and porosity of the aquifer are not reduced significantly by heating. We present an overview...... of published results regarding the effect of temperature on sandstone permeability. These tests are performed with mineral oil, nitrogen gas, distilled water and solutions of NaCl, KCl, CaCl2 as well as brines that contain a mixture of salts. Thirteen sandstone formations, ranging from quartz arenites...... not account for all the permeability reductions observed. Permeablity reduction occurs both when distilled water is the saturating fluid as well as in tests with NaCl, KCl or CaCl2 solutions, however, this is not the case in tests with mineral oil or nitrogen gas. The formation of a filter cake or influx...

  3. Medium-temperature air-heater development program. Final report, October 1, 1977-December 31, 1978

    Energy Technology Data Exchange (ETDEWEB)

    1979-04-15

    A program to design, fabricate, and verify by test a low-cost (in volume production), modularized, practical solar air heater adaptable for new or retrofit space-heating and hot-water applications is described. The unique hardware elements of the SOLAIR II medium-temperature air heater described are the TCA solar collectors, energy transfer module, interconnecting ductwork, and mounting hardware. SOLAIR II is a two-tank domestic hot-water-augmented system. The system is described in detail; market and design analyses are described; fabrication procedures are noted; and design verification tests and results are discussed. The design used for the pre-production lot was essentially the SOLAIR II design and will serve as the basis for future design evaluations as the product is introduced into the commercial market.

  4. Overheating in Hot Water- and Steam-Heated Multifamily Buildings

    Energy Technology Data Exchange (ETDEWEB)

    Dentz, J. [ARIES Collaborative, New York, NY (United States); Varshney, K. [ARIES Collaborative, New York, NY (United States); Henderson, H. [ARIES Collaborative, New York, NY (United States)

    2013-10-01

    In this project, the ARIES Building America team collected apartment temperature data from the archives of companies that provide energy management systems (EMS) to multifamily buildings in the Northeast U.S. Data was analyzed from more than 100 apartments in eighteen buildings where EMS systems were already installed to quantify the degree of overheating in an effort to answer the question, "What is the magnitude of apartment overheating in multifamily buildings with central hot water or steam heat?" This report provides valuable information to researchers, utility program managers and building owners interested in controlling heating energy waste and improving resident comfort.

  5. Failure rates of tube systems used in delivery-water heaters of T-250/300-240 turbine units

    Science.gov (United States)

    Vasilenko, G. V.; Nikitin, V. I.; Meshcheryakov, I. M.; Murzin, M. A.

    2007-11-01

    Field experience data on the stress corrosion cracking of a tube system made of Grade 12Kh18N10T austenitic stainless steel are given. The pattern of damages and the factors causing them to appear in certain locations are analyzed. Design and operational solutions aimed at making the heaters more reliable are proposed.

  6. In vitro Activity of Ethanol, Cold Water and Hot Water Extracts of the ...

    African Journals Online (AJOL)

    An in vitro evaluation was performed to determine the efficacy of ethanol, cold water and hot water extracts of the stem bark of Canthium mannii (Rubiaceae) on un-embryonated and embryonated eggs of Ancylostoma caninum obtained from the faeces of naturally infected local dogs. The extracts were diluted in distilled ...

  7. Metal oxide nanostructures by a simple hot water treatment.

    Science.gov (United States)

    Saadi, Nawzat S; Hassan, Laylan B; Karabacak, Tansel

    2017-08-02

    Surfaces with metal oxide nanostructures have gained considerable interest in applications such as sensors, detectors, energy harvesting cells, and batteries. However, conventional fabrication techniques suffer from challenges that hinder wide and effective applications of such surfaces. Most of the metal oxide nanostructure synthesis methods are costly, complicated, non-scalable, environmentally hazardous, or applicable to only certain few materials. Therefore, it is crucial to develop a simple metal oxide nanostructure fabrication method that can overcome all these limitations and pave the way to the industrial application of such surfaces. Here, we demonstrate that a wide variety of metals can form metal oxide nanostructures on their surfaces after simply interacting with hot water. This method, what we call hot water treatment, offers the ability to grow metal oxide nanostructures on most of the metals in the periodic table, their compounds, or alloys by a one-step, scalable, low-cost, and eco-friendly process. In addition, our findings reveal that a "plugging" mechanism along with surface diffusion is critical in the formation of such nanostructures. This work is believed to be of importance especially for researchers working on the growth of metal oxide nanostructures and their application in functional devices.

  8. Optimum hot water temperature for absorption solar cooling

    Energy Technology Data Exchange (ETDEWEB)

    Lecuona, A.; Ventas, R.; Venegas, M.; Salgado, R. [Dpto. Ingenieria Termica y de Fluidos, Universidad Carlos III de Madrid, Avda. Universidad 30, 28911 Leganes, Madrid (Spain); Zacarias, A. [ESIME UPA, IPN, Av. de las Granjas 682, Col. Santa Catarina, 02550, D.F. Mexico (Mexico)

    2009-10-15

    The hot water temperature that maximizes the overall instantaneous efficiency of a solar cooling facility is determined. A modified characteristic equation model is used and applied to single-effect lithium bromide-water absorption chillers. This model is based on the characteristic temperature difference and serves to empirically calculate the performance of real chillers. This paper provides an explicit equation for the optimum temperature of vapor generation, in terms of only the external temperatures of the chiller. The additional data required are the four performance parameters of the chiller and essentially a modified stagnation temperature from the detailed model of the thermal collector operation. This paper presents and discusses the results for small capacity machines for air conditioning of homes and small buildings. The discussion highlights the influence of the relevant parameters. (author)

  9. Model based control and optimization of a feed-water heater train; Modellbaserad reglering och optimering av en foervaermarekedja

    Energy Technology Data Exchange (ETDEWEB)

    Velut, Stephane; Raaberg, Martin; Wendel, Hans (Grontmij AB (SE))

    2007-12-15

    Thermal power plants are complex processes in which many variables must be monitored and controlled in real-time for a safe and economic operation. The complex interactions between actuators and controlled variables as well as the load dependent dynamics make the design and tuning of all controllers a challenging task. A mathematical model of the process that describes critical characteristics such as dynamics, interactions, and nonlinearities might greatly facilitate the task of the control engineer. Such controllers can be designed in a rather systematic way to achieve good performance in terms of response time and robustness. This enables the operator to run the process closer to its limits while minimizing damage risks. The goal of the project was threefold. The first objective was to describe the available methods to compute process models directly from experimental data and illustrate how those models can be used for control design. The second objective was to apply some of the fore mentioned methods on a specific process, namely a feed water heater train to control the level in each preheater. The third objective was to analyze how the level in each preheater affects the thermal efficiency of the plant and derive adequate set-points for the model-based controllers. The project started at the end of the production season, which resulted in a tight schedule for the planning and the realization of experiments. Informative data could however be collected and models could be derived for some specific loads. Unfortunately the effect of the changes in the level set point could not be verified because of the limited length of the experiments. The project results can be summarized as follows: The way the condensate level should be chosen in every preheater has been formulated as a simple optimization problem that aims as maximizing the thermal efficiency of the plant. Even though the model used in the optimization was simple, the results were pretty intuitive. The

  10. Automatic supervision of solar heating systems. Part 1: Solar kits for domestic hot water preparation; Supervision automatique d'installations solaires thermiques. Premiere partie consacree aux kits solaires de production d'eau chaude sanitaire. Rapport final

    Energy Technology Data Exchange (ETDEWEB)

    Prud' homme, T.; Gillet, D.

    1999-07-01

    The system under consideration is a solar domestic hot water heating system (SDHWS) manufactured in Switzerland. The heat exchanger is a mantle, which surrounds the entire storage tank. One major structural improvement has been designed. It consists in the replacement of the auxiliary heater made of one single electrical element by three smaller ones with different lengths. This configuration requires the manipulation of two additional actuators. Therefore, an advanced control strategy has also been considered for all the actuators manipulated. These actuators are the pump driving the fluid in the collector loop and the three electrical elements. Weather forecasts provided on-line by the Swiss Institute of Meteorology (SIM) as well as the estimation of the users' needs in terms of tapped water are integrated in this advanced control strategy. The segmentation of the auxiliary heater together with a suitable advanced control strategy have led to significant improvements in terms of comfort and energy consumption. (author)

  11. Development of an Ultra-Low-Cost Solar Water Heater: Cooperative Research and Development Final Report, CRADA Number CRD-12-487

    Energy Technology Data Exchange (ETDEWEB)

    Merrigan, Tim [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2016-02-17

    NREL and RhoTech will collaborate to bring long-lived, ultra-low-cost, high-performance solar water heaters (SWH) to market readiness. An existing RhoTech design uses seam-welded polymer thin films to make an unglazed thermosiphon, and this design will be modified to improve durability through ultraviolet and overheat protection, and to improve performance by adding a glazing to the collector. Two generations of the new glazed systems will be tested in the field, resulting in a robust market-ready SWH design that can be installed for under $1,000 without rebates.

  12. Degradation of fish gelatin using hot-compressed water and the properties of the degradation products

    Science.gov (United States)

    Ueno, Shigeaki; Ichinoi, Hirokazu; Zhao, Jiahui; Fujii, Tomoyuki

    2015-04-01

    The degradation of fish gelatin using hot-compressed water was investigated. The hot-compressed water treatment resulted in the degradation of fish gelatin into peptides, and the number of the peptides increased with increasing the temperature. The distribution of amino acids in the product mixture indicated that hot-compressed water treatment at 240°C resulted in a high level of amino acid degradation, and the highest concentrations of free amino acids was at 220°C. Lysinoalanine, which is toxic, was rarely generated by hot-compressed water treatment at higher temperature range. Additionally, the optimum temperature for the hot-compressed water treatment with respect to the angiotensin I-converting enzyme inhibitory was at 180°C. These analyses demonstrate that the degradation of fish gelatin with hot-compressed water could be used to generate functional materials.

  13. Emission of Air Pollutants in the Hot Water Production

    Science.gov (United States)

    Krzysztof, Nowak; Maria, Bukowska; Danuta, Proszak-Miąsik; Sławomir, Rabczak

    2017-10-01

    The result of the deteriorating condition of the environment and climate change is to increase the efficient use of fuel and energy and the rational use of energy resources. Great potential for reducing consumption of fossil fuels are stuck in heating systems ranging from generation, transmission and distribution and ending with the recipients rationalize their consumption of heat. Efficient production of heat is obtained during optimal boiler load. The boiler type WR operates with the highest efficiency of 80-85%, the rate of fuel consumption is the lowest, and the process is close to complete combustion. In such conditions to the atmosphere are emitted mainly: SO2, CO2 and NOX. Pollutants such as CO, CH4, HF, HCl, NH3, etc., are the result of incomplete and imperfect combustion, that is, when the boiler is working inefficiently [1-3]. Measurements of pollutant concentrations were performed using an analyzer FTIR Gasmet DX4000. Fourier Transform Infrared Spectroscopy is a technique of measuring that allows a very precise identification of qualitative and quantitative range of compounds, including gaseous pollutants. Device used to measure the concentrations of gaseous pollutants allow determining the amount of carbon, sulphur and nitrogen compounds, which measurement is not defined any rules, including chlorine compounds, hydrogen, methane, ammonia and volatile organic compounds. In this publication presents part of the literature the use of heat for domestic hot water production in summer and heating demand in winter. Described the characteristics of the water boilers WR type used for heating. Presents the results study of the emissions in the production of hot water for the summer and winter seasons.

  14. Performance Study of a Cylindrical Parabolic Concentrating Solar Water Heater with Nail Type Twisted Tape Inserts in the Copper Absorber Tube

    Directory of Open Access Journals (Sweden)

    Amit K. Bhakta

    2018-01-01

    Full Text Available This paper reports the overall thermal performance of a cylindrical parabolic concentrating solar water heater (CPCSWH with inserting nail type twisted tape (NTT in the copper absorber tube for the nail twist pitch ratios, 4.787, 6.914 and 9.042, respectively. The experiments are conducted for a constant volumetric water flow rate and during the time period 9:00 a.m. to 15:00 p.m. The useful heat gain, hourly solar energy collected and hourly solar energy stored in this solar water heater were found to be higher for the nail twist pitch ratio 4.787. The above said parameters were found to be at a peak at noon and observed to follow the path of variation of solar intensity. At the start of the experiment, the value of charging efficiency was observed to be maximum, whereas the maximum values of instantaneous efficiency and overall thermal efficiency were observed at noon. The key finding is that the nail twist pitch ratio enhances the overall thermal performance of the CPCSWH.

  15. Development of equipment for in situ studies of biofilm in hot water systems

    DEFF Research Database (Denmark)

    Bagh, Lene Karen; Albrechtsen, Hans-Jørgen; Arvin, Erik

    1999-01-01

    New equipment was developed for in situ studies of biofilms in hot water tanks and hot water pipes under normal operation and pressure. Sampling ports were installed in the wall of a hot water tank and through these operating shafts were inserted with a test plug in the end. The surface of the test...... in sampling ports in a by-pass. Heterotrophic plate counts (HPC) revealed 10(4)-10(6) CFU cm(-2) on the test plugs in the hot water system after an exposure period of 7 d. The number of bacteria was not influenced by the location of the plug within each cluster of plugs in the distribution system...

  16. Analysis of proposed eco-design requirements for boilers and water heaters. Paper within the framwork of the ''Material Efficiency and Resource Conservation'' (MaRess) Project - Task 14

    Energy Technology Data Exchange (ETDEWEB)

    Barthel, Klaus; Franke, Moritz [Wuppertal Institute for Climate, Environment and Energy, Wuppertal (Germany)

    2009-12-15

    In 2005, the European Union released the EuP Directive focusing on ecodesign requirements for energy-using products (2005/32/EC: EU Parliament and Council of the EU 2005). This directive, also called Ecodesign Directive, is a framework directive establishing a structure in which so-called implementing measures define specific requirements for placing products on the market and/or putting them into service within the internal European market. These requirements can be environmental performance standards (e.g. minimum energy efficiency or emission standards) and labelling or information requirements. Some existing European directives are already declared as being implementing measures of the Ecodesign Directive. Additionally, new implementing measures have been and will further be developed. Product-specific preparatory studies on behalf of the European Commission provide the basis for this. The preparatory studies for boilers (Lot 1) and water heaters (Lot 2) have been conducted from February 2006 to October 2007 by Van Holsteijn en Kemna (VHK). Based on the preparatory studies, the EU Commission has released several working documents (WD) on possible ecodesign requirements for boilers and water heaters at the beginning of 2008. Following these documents, boilers and water heaters comprise gas-fired, oil-fired and electric central heating (CH) (combi-) boilers / dedicated water heaters in combination with capturing solar thermal energy or ambient heat1. The requirements contain basically energy labelling measures, minimum efficiency performance standards and limits on NOx emissions. An ''Ecoboiler Model'' resp. an ''Eco Hot Water Model'' has been elaborated within the preparatory studies. These models are a crucial part of the requirements and allow for calculation of the efficiencies of boilers and water heaters. Since the models have a high degree of complexity, the Federal Environment Agency (UBA) has asked Wuppertal

  17. Carbonate ion-enriched hot spring water promotes skin wound healing in nude rats.

    Directory of Open Access Journals (Sweden)

    Jingyan Liang

    Full Text Available Hot spring or hot spa bathing (Onsen is a traditional therapy for the treatment of certain ailments. There is a common belief that hot spring bathing has therapeutic effects for wound healing, yet the underlying molecular mechanisms remain unclear. To examine this hypothesis, we investigated the effects of Nagano hot spring water (rich in carbonate ion, 42°C on the healing process of the skin using a nude rat skin wound model. We found that hot spring bathing led to an enhanced healing speed compared to both the unbathed and hot-water (42°C control groups. Histologically, the hot spring water group showed increased vessel density and reduced inflammatory cells in the granulation tissue of the wound area. Real-time RT-PCR analysis along with zymography revealed that the wound area of the hot spring water group exhibited a higher expression of matrix metalloproteinases-2 and -9 compared to the two other control groups. Furthermore, we found that the enhanced wound healing process induced by the carbonate ion-enriched hot spring water was mediated by thermal insulation and moisture maintenance. Our results provide the evidence that carbonate ion-enriched hot spring water is beneficial for the treatment of skin wounds.

  18. Grouped exposed metal heaters

    Energy Technology Data Exchange (ETDEWEB)

    Vinegar, Harold J. (Bellaire, TX); Coit, William George (Bellaire, TX); Griffin, Peter Terry (Brixham, GB); Hamilton, Paul Taylor (Houston, TX); Hsu, Chia-Fu (Granada Hills, CA); Mason, Stanley Leroy (Allen, TX); Samuel, Allan James (Kular Lumpar, MY); Watkins, Ronnie Wade (Cypress, TX)

    2010-11-09

    A system for treating a hydrocarbon containing formation is described. The system includes two or more groups of elongated heaters. The group includes two or more heaters placed in two or more openings in the formation. The heaters in the group are electrically coupled below the surface of the formation. The openings include at least partially uncased wellbores in a hydrocarbon layer of the formation. The groups are electrically configured such that current flow through the formation between at least two groups is inhibited. The heaters are configured to provide heat to the formation.

  19. Grouped exposed metal heaters

    Energy Technology Data Exchange (ETDEWEB)

    Vinegar, Harold J [Bellaire, TX; Coit, William George [Bellaire, TX; Griffin, Peter Terry [Brixham, GB; Hamilton, Paul Taylor [Houston, TX; Hsu, Chia-Fu [Granada Hills, CA; Mason, Stanley Leroy [Allen, TX; Samuel, Allan James [Kular Lumpar, ML; Watkins, Ronnie Wade [Cypress, TX

    2012-07-31

    A system for treating a hydrocarbon containing formation is described. The system includes two or more groups of elongated heaters. The group includes two or more heaters placed in two or more openings in the formation. The heaters in the group are electrically coupled below the surface of the formation. The openings include at least partially uncased wellbores in a hydrocarbon layer of the formation. The groups are electrically configured such that current flow through the formation between at least two groups is inhibited. The heaters are configured to provide heat to the formation.

  20. Hot water epilepsy: seizure type, water temperature, EEG findings and treatment.

    Science.gov (United States)

    Zeki, Gokcil; Gokcil, Zeki; Ilker, Ipekdal Huseyin; Ipekdal, Huseyin Ilker; Hidir, Ulas Umit; Ulas, Umit Hidir; Zeki, Odabasi; Odabasi, Zeki

    2010-03-01

    Hot water epilepsy (HWE) or bathing epilepsy is one of the reflex epilepsies induced by hot water pouring over the head, face, neck, or trunk during bathing. The aim of this study was to demonstrate the clinical and electroencephalographic features and the management alternatives of the patients with HWE. The age of seizure onset, duration of seizure, family history, interictal and postictal electroencephalography findings, triggering temperature of water, type of seizure, medication, and follow-up results were evaluated for each patient. The mean age at seizure onset was 10.5 years. The mean duration of seizures was 10 years. Interictal EEG recordings showed focal abnormalities in 4 patients and generalized abnormalities in 3 patients. Only one patient had normal interictal EEG findings. Among the 8 patients with HWE, 6 had seizures only during hot bathing, whereas 2 had additional seizures. Seven patients had generalized tonic-clonic seizures and 1 patient had complex partial seizure during their hot bathings. The mean triggering temperature of water was calculated as 41.4 degrees C. The mean duration of follow-up period was 23 months. Five patients became seizure-free during the follow-up period and seizures persisted in 3 patients. Antiepileptic drugs were given (800 mg/d carbamazepine for 2 patients and 600 mg/d phenytoin for 1 patient) to these 3 patients and they also became seizure-free during the follow-up period. Hot water epilepsy is a benign reflex epilepsy. Lowering water temperature must be the first step for the treatment. If needed, antiepileptic drugs should be considered as an additive treatment.

  1. Water Quality Study on the Hot and Cold Water Supply Systems at Vietnamese Hotels

    Directory of Open Access Journals (Sweden)

    Kanako Toyosada

    2017-04-01

    Full Text Available This study was conducted as part of the Joint Crediting Mechanism (JCM of the Japanese Ministry of Economy, Trade and Industry, and the Ministry of the Environment project’s preparation in Vietnam. Samples were taken from hot and cold water supplies from guest rooms’ faucets in 12 hotels in Hanoi city, Vietnam, and 13 hotels in Japan for comparison. A simple water quality measurement and determination of Legionella was carried out. The results showed that residual effective chlorine—which guarantees bactericidal properties—was not detected in tap water supplied in hotel rooms in Vietnam, and nitrite (an indicator of water pollution was detected in 40% of buildings. In the hotels in Japan, the prescribed residual chlorine concentration met the prescribed levels, and nitrite was not detected. Additionally, while there was no Legionella detected in the Japanese cases, it was detected in most of the Vietnamese hotels, which were found to manage the hot water storage tank at low temperatures of 40–50 °C. It was found that there were deficiencies in cold and hot water supply quality, and that there was no effective system in place for building operation maintenance and management.

  2. Dynamics of microdroplets over the surface of hot water

    Science.gov (United States)

    Umeki, Takahiro; Ohata, Masahiko; Nakanishi, Hiizu; Ichikawa, Masatoshi

    2015-01-01

    When drinking a cup of coffee under the morning sunshine, you may notice white membranes of steam floating on the surface of the hot water. They stay notably close to the surface and appear to almost stick to it. Although the membranes whiffle because of the air flow of rising steam, peculiarly fast splitting events occasionally occur. They resemble cracking to open slits approximately 1 mm wide in the membranes, and leave curious patterns. We studied this phenomenon using a microscope with a high-speed video camera and found intriguing details: i) the white membranes consist of fairly monodispersed small droplets of the order of 10 μm ii) they levitate above the water surface by 10 ~ 100 μm iii) the splitting events are a collective disappearance of the droplets, which propagates as a wave front of the surface wave with a speed of 1 ~ 2 m/s and iv) these events are triggered by a surface disturbance, which results from the disappearance of a single droplet.

  3. Solar heating and hot water system installed at office building, One Solar Place, Dallas, Texas

    Science.gov (United States)

    1980-06-01

    A solar heating on cooling system is described which is designed to provide 87 percent of the space heating needs, 100 percent of the potable hot water needs and is sized for future absorption cooling. The collection subsystem consists of 28 solargenics, series 76, flat plate collectors with a total area of 1,596 square feet. The solar loop circulates an ethylene glyco water solution through the collectors into a hot water system exchanger. The water storage subsystem consists of a heat exchanger, two 2,300 gallon concrete hot water storage tanks with built in heat exchangers and a back-up electric boiler. The domestic hot water subsystem sends hot water to the 10,200 square feet floor area office building hot water water fixtures. The building cold water system provides make up to the solar loop, the heating loop, and the hot water concrete storage tanks. The design, construction, cost analysis, operation and maintenance of the solar system are described.

  4. Application of the genetic algorithm for optimisation of large solar hot water systems

    NARCIS (Netherlands)

    Loomans, M.G.L.C.; Visser, H.

    2002-01-01

    An implementation of the genetic algorithm in a design support tool for (large) solar hot water systems is described. The tool calculates the yield and the costs of solar hot water systems based on technical and financial data of the system components. The genetic algorithm allows for optimisation

  5. Risk of Burns from Eruptions of Hot Water Overheated in Microwave Ovens

    Science.gov (United States)

    ... Burns from Eruptions of Hot Water Overheated in Microwave Ovens Share Tweet Linkedin Pin it More sharing options ... after it had been over-heated in a microwave oven. Over-heating of water in a cup can ...

  6. Data from Sustainability Base Characterizing Hot Water Pump Differential Pressure Spikes for ACCEPT

    Data.gov (United States)

    National Aeronautics and Space Administration — During the heating season in Sustainability Base, a critical alarm associated with a hot water pump circulating heating water for the radiative system which...

  7. Experimental Validation of a Domestic Stratified Hot Water Tank Model in Modelica for Annual Performance Assessment

    DEFF Research Database (Denmark)

    Carmo, Carolina; Dumont, Olivier; Nielsen, Mads Pagh

    2015-01-01

    The use of stratified hot water tanks in solar energy systems - including ORC systems - as well as heat pump systems is paramount for a better performance of these systems. However, the availability of effective and reliable models to predict the annual performance of stratified hot water tanks c...... with direct inlet and outlet and immersed heat exchangers. Results of experimental and numerical investigations in a residential hot water tank with two immersed heat exchangers, one inlet and one outlet are presented and the performance of the model is assessed.......The use of stratified hot water tanks in solar energy systems - including ORC systems - as well as heat pump systems is paramount for a better performance of these systems. However, the availability of effective and reliable models to predict the annual performance of stratified hot water tanks...

  8. Assessment of radioisotope heaters for remote terrestrial applications

    Energy Technology Data Exchange (ETDEWEB)

    Uherka, K.L.

    1987-05-01

    This paper examines the feasibility of using radioisotope byproducts for special heating applications at remote sites in Alaska and other cold regions. The investigation included assessment of candidate radioisotope materials for heater applications, identification of the most promising cold region applications, evaluation of key technical issues and implementation constraints, and development of conceptual heater designs for candidate applications. Strontium-90 (Sr-90) was selected as the most viable fuel for radioisotopic heaters used in terrestrial applications. Opportunities for the application of radioisotopic heaters were determined through site visits to representative Alaska installations. Candidate heater applications included water storage tanks, sludge digesters, sewage lagoons, water piping systems, well-head pumping stations, emergency shelters, and fuel storage tank deicers. Radioisotopic heaters for water storage tank freeze-up protection and for enhancement of biological waste treatment processes at remote sites were selected as the most promising applications.

  9. To Duct or Not to Duct: Evaluating the Space Conditioning Impacts of Heat Pump Water Heaters in the PNNL Lab Homes

    Energy Technology Data Exchange (ETDEWEB)

    Widder, Sarah H.; Parker, Graham B.; Peeks, B.; Sullivan, Greg; Shaffer, Scott

    2014-08-22

    Heat pump water heaters (HPWH) are a promising technology for substantially reducing water heating-related energy use in the residential sector. However, concerns have been raised regarding the impact of HPWHs on space conditioning energy when installed in conditioned space, primarily in northern climates. For example, the Northwest Energy Efficiency Alliance (NEEA’s) Northern Climate HPWH Specification, which describes the characteristics a HPWH must have to be incentivized in cold climates in the Pacific Northwest (PNW), requires exhaust ducting for their Tier II-specified products and both supply and exhaust ducting for the Tier III-specified product (NEEA 2013). However, these concerns and installation recommendations are based on modeling and comparative field data are not available to verify modeled performance. This study examines the overall performance and operation of two GE GeoSpring HPWHs in conditioned space in the matched pair of PNNL Lab Homes with no ducting, exhaust ducting, and full ducting (supply and exhaust) and explores the interactions between the HPWH and the home’s heating/cooling system. The data collected in this field evaluation suggest that previous modeling may not completely characterize the complex interactions of HPWHs, HVAC systems, and ducting. This report discusses the impact on space conditioning and water heater energy use of configuring an HPWH with exhaust only ducting or full ducting, as compared to an unducted HPWH. Additional cost analysis is necessary to assess the cost effectiveness of ducting and to make formal recommendations regarding appropriate installation of HPWHs in more varied scenarios.

  10. Hydrolysis kinetics of tulip tree xylan in hot compressed water.

    Science.gov (United States)

    Yoon, Junho; Lee, Hun Wook; Sim, Seungjae; Myint, Aye Aye; Park, Hee Jeong; Lee, Youn-Woo

    2016-08-01

    Lignocellulosic biomass, a promising renewable resource, can be converted into numerous valuable chemicals post enzymatic saccharification. However, the efficacy of enzymatic saccharification of lignocellulosic biomass is low; therefore, pretreatment is necessary to improve the efficiency. Here, a kinetic analysis was carried out on xylan hydrolysis, after hot compressed water pretreatment of the lignocellulosic biomass conducted at 180-220°C for 5-30min, and on subsequent xylooligosaccharide hydrolysis. The weight ratio of fast-reacting xylan to slow-reacting xylan was 5.25 in tulip tree. Our kinetic results were applied to three different reaction systems to improve the pretreatment efficiency. We found that semi-continuous reactor is promising. Lower reaction temperatures and shorter space times in semi-continuous reactor are recommended for improving xylan conversion and xylooligosaccharide yield. In the theoretical calculation, 95% of xylooligosaccharide yield and xylan conversion were achieved simultaneously with high selectivity (desired product/undesired product) of 100 or more. Copyright © 2016. Published by Elsevier Ltd.

  11. Seasonal dynamics of bacterial community structure and composition in cold and hot drinking water derived from surface water reservoirs.

    Science.gov (United States)

    Henne, Karsten; Kahlisch, Leila; Höfle, Manfred G; Brettar, Ingrid

    2013-10-01

    In temperate regions, seasonal variability of environmental factors affects the bacterial community in source water and finished drinking water. Therefore, the bacterial core community and its seasonal variability in cold and the respective hot drinking water was investigated. The bacterial core community was studied by 16S rRNA-based SSCP fingerprint analyses and band sequencing of DNA and RNA extracts of cold and hot water (60 °C). The bacterial communities of cold and hot drinking water showed a highly different structure and phylogenetic composition both for RNA and DNA extracts. For cold drinking water substantial seasonal dynamics of the bacterial community was observed related to environmental factors such as temperature and precipitation affecting source and drinking water. Phylogenetic analyses of the cold water community indicated that the majority of phylotypes were very closely affiliated with those detected in former studies of the same drinking water supply system (DWSS) in the preceding 6 years, indicating a high stability over time. The hot water community was very stable over time and seasons and highly distinct from the cold water with respect to structure and composition. The hot water community displayed a lower diversity and its phylotypes were mostly affiliated with bacteria of high temperature habitats with high growth rates indicated by their high RNA content. The conversion of the cold to the hot water bacterial community is considered as occurring within a few hours by the following two processes, i) by decay of most of the cold water bacteria due to heating, and ii) rapid growth of the high temperature adapted bacteria present in the hot water (co-heated with the cold water in the same device) using the nutrients released from the decaying cold water bacteria. The high temperature adapted bacteria originated partially from low abundant but beforehand detected members of the cold water; additionally, the rare members ("seed bank ") of the

  12. Toward Complete Utilization of Miscanthus in a Hot-Water Extraction-Based Biorefinery

    Directory of Open Access Journals (Sweden)

    Kuo-Ting Wang

    2017-12-01

    Full Text Available Miscanthus (Miscanthus sp. Family: Poaceae was hot-water extracted (two h, at 160 °C at three scales: laboratory (Parr reactor, 300 cm3, intermediate (M/K digester, 4000 cm3, and pilot (65 ft3-digester, 1.841 × 106 cm3. Hot-water extracted miscanthus, hydrolyzate, and lignin recovered from hydrolyzate were characterized and evaluated for potential uses aiming at complete utilization of miscanthus. Effects of scale-up on digester yield, removal of hemicelluloses, deashing, delignification degree, lignin recovery and purity, and cellulose retention were studied. The scale-dependent results demonstrated that before implementation, hot-water extraction (HWE should be evaluated on a scale larger than a laboratory scale. The production of energy-enriched fuel pellets from hot-water extracted miscanthus, especially in combination with recovered lignin is recommended, as energy of combustion increased gradually from native to hot-water extracted miscanthus to recovered lignin. The native and pilot-scale hot-water extracted miscanthus samples were also subjected to enzymatic hydrolysis using a cellulase-hemicellulase cocktail, to produce fermentable sugars. Hot-water extracted biomass released higher amount of glucose and xylose verifying benefits of HWE as an effective pretreatment for xylan-rich lignocellulosics. The recovered lignin was used to prepare a formaldehyde-free alternative to phenol-formaldehyde resins and as an antioxidant. Promising results were obtained for these lignin valorization pathways.

  13. Hot water epilepsy: a video case of European boy with positive family history and subsequent non-reflex epilepsy.

    Science.gov (United States)

    Vignoli, Aglaia; Savini, Miriam Nella; La Briola, Francesca; Chiesa, Valentina; Zambrelli, Elena; Peron, Angela; Canevini, Maria Paola

    2014-03-01

    A 9-year-old Caucasian boy affected by hot water epilepsy, with positive family history, experienced complex partial seizures during contact with hot water. A video-EEG recording was taken while hot water was poured onto his chest. Hot water epilepsy is rarely described in European countries, where bathing epilepsy in younger children is more common and often confused with this type of epilepsy.

  14. Solar heating and hot water system installed at Cherry Hill, New Jersey

    Science.gov (United States)

    1979-01-01

    The solar heating and hot water system installed in existing buildings at the Cherry Hill Inn in Cherry Hill, New Jersey is described in detail. The system is expected to furnish 31.5% of the overall heating load and 29.8% of the hot water load. The collectors are liquid evacuated tube type. The storage system is an above ground insulated steel water tank with a capacity of 7,500 gallons.

  15. Impacts of Water Quality on Residential Water Heating Equipment

    Energy Technology Data Exchange (ETDEWEB)

    Widder, Sarah H.; Baechler, Michael C.

    2013-11-01

    Water heating is a ubiquitous energy use in all residential housing, accounting for 17.7% of residential energy use (EIA 2012). Today, there are many efficient water heating options available for every fuel type, from electric and gas to more unconventional fuel types like propane, solar, and fuel oil. Which water heating option is the best choice for a given household will depend on a number of factors, including average daily hot water use (total gallons per day), hot water draw patterns (close together or spread out), the hot water distribution system (compact or distributed), installation constraints (such as space, electrical service, or venting accommodations) and fuel-type availability and cost. While in general more efficient water heaters are more expensive than conventional water heating technologies, the savings in energy use and, thus, utility bills can recoup the additional upfront investment and make an efficient water heater a good investment over time in most situations, although the specific payback period for a given installation will vary widely. However, the expected lifetime of a water heater in a given installation can dramatically influence the cost effectiveness and savings potential of a water heater and should be considered, along with water use characteristics, fuel availability and cost, and specific home characteristics when selecting the optimum water heating equipment for a particular installation. This report provides recommendations for selecting and maintaining water heating equipment based on local water quality characteristics.

  16. Final report : testing and evaluation for solar hot water reliability.

    Energy Technology Data Exchange (ETDEWEB)

    Caudell, Thomas P. (University of New Mexico, Albuquerque, NM); He, Hongbo (University of New Mexico, Albuquerque, NM); Menicucci, David F. (Building Specialists, Inc., Albuquerque, NM); Mammoli, Andrea A. (University of New Mexico, Albuquerque, NM); Burch, Jay (National Renewable Energy Laboratory, Golden CO)

    2011-07-01

    Solar hot water (SHW) systems are being installed by the thousands. Tax credits and utility rebate programs are spurring this burgeoning market. However, the reliability of these systems is virtually unknown. Recent work by Sandia National Laboratories (SNL) has shown that few data exist to quantify the mean time to failure of these systems. However, there is keen interest in developing new techniques to measure SHW reliability, particularly among utilities that use ratepayer money to pay the rebates. This document reports on an effort to develop and test new, simplified techniques to directly measure the state of health of fielded SHW systems. One approach was developed by the National Renewable Energy Laboratory (NREL) and is based on the idea that the performance of the solar storage tank can reliably indicate the operational status of the SHW systems. Another approach, developed by the University of New Mexico (UNM), uses adaptive resonance theory, a type of neural network, to detect and predict failures. This method uses the same sensors that are normally used to control the SHW system. The NREL method uses two additional temperature sensors on the solar tank. The theories, development, application, and testing of both methods are described in the report. Testing was performed on the SHW Reliability Testbed at UNM, a highly instrumented SHW system developed jointly by SNL and UNM. The two methods were tested against a number of simulated failures. The results show that both methods show promise for inclusion in conventional SHW controllers, giving them advanced capability in detecting and predicting component failures.

  17. Explosives tester with heater

    Science.gov (United States)

    Del Eckels, Joel [Livermore, CA; Nunes, Peter J [Danville, CA; Simpson, Randall L [Livermore, CA; Whipple, Richard E [Livermore, CA; Carter, J Chance [Livermore, CA; Reynolds, John G [San Ramon, CA

    2010-08-10

    An inspection tester system for testing for explosives. The tester includes a body and a swab unit adapted to be removeably connected to the body. At least one reagent holder and dispenser is operatively connected to the body. The reagent holder and dispenser contains an explosives detecting reagent and is positioned to deliver the explosives detecting reagent to the swab unit. A heater is operatively connected to the body and the swab unit is adapted to be operatively connected to the heater.

  18. Physical and chemical parameter correlations with technical and technological characteristics of heating systems and the presence of Legionella spp. in the hot water supply.

    Science.gov (United States)

    Rakić, Anita; Štambuk-Giljanović, Nives

    2016-02-01

    The purpose of this study was to evaluate the prevalence of Legionella spp. and compare the quality of hot water between four facilities for accommodation located in Southern Croatia (the Split-Dalmatian County). The research included data collection on the technical and technological characteristics in the period from 2009 to 2012. The survey included a type of construction material for the distribution and internal networks, heating system water heater type, and water consumption. Changes in water quality were monitored by determination of the physical and chemical parameters (temperature, pH, free chlorine residual concentrations, iron, zinc, copper and manganese) in the samples, as well as the presence and concentration of bacteria Legionella spp. The temperature is an important factor for the development of biofilms, and it is in negative correlation with the appearance of Legionella spp. Positive correlations between the Fe and Zn concentrations and Legionella spp. were established, while the inhibitory effect of a higher Cu concentration on the Legionella spp. concentration was proven. Legionella spp. were identified in 38/126 (30.2%) of the water samples from the heating system with zinc-coated pipes, as well as in 78/299 (26.1%) of the samples from systems with plastic pipes. A similar number of Legionella spp. positive samples were established regardless of the type of the water heating system (central or independent). The study confirms the necessity of regular microbial contamination monitoring of the drinking water distribution systems (DWDSs).

  19. Heat inactivation of wine spoilage yeast Dekkera bruxellensis by hot water treatment

    National Research Council Canada - National Science Library

    Fabrizio, V; Vigentini, I; Parisi, N; Picozzi, C; Compagno, C; Foschino, R

    2015-01-01

    .... The thermal inactivation of D. bruxellensis cells by hot water treatment proves to be efficacious and easy to perform, provided that the holding time at the killing temperature takes into account the filling time of the vessel...

  20. About economy of fuel and energy resources in the hot water supply system

    Science.gov (United States)

    Rotov, P. V.; Sivukhin, A. A.; Zhukov, D. A.; Zhukova, A. V.

    2017-11-01

    The assessment of the power efficiency realized in the current of heat supply system of technology of regulation of loading of the hot water supply system, considering unevenness consumption of hot water is executed. For the purpose of definition the applicability boundary of realized technology comparative analysis of indicators of the effectiveness of its work within the possible range of the parameters of regulations. Developed a software application “The calculation of the total economy of fuel and energy resources in the hot water supply system when you change of the parameters of regulations”, which allows on the basis of multivariate calculations analyses of their results, to choose the optimum mode of operation heat supply system and to assess the effectiveness of load regulation in the hot water supply system.

  1. Effects of Hot Water Immersion on Storage Quality of Fresh Broccoli Heads

    Directory of Open Access Journals (Sweden)

    Huaqiang Dong

    2004-01-01

    Full Text Available Freshly harvested broccoli heads were immersed for 0, 1, 4 or 8 min into hot water at 45 °C, and then were hydrocooled rapidly for 10 min at 10 °C. Following these treatments, the broccoli were air-dried for 30 min, then packed in commercial polymeric film bags, and, finally, stored for 16 days at –1, 1, and 12 °C. The samples treated with hot water maintained high contents of chlorophyll concentrations, their yellowing rate was delayed, and fungal infection and chilling or freezing injury were inhibited markedly. Compared to non-heat-treated broccoli, a lower level of peroxidase activity with a relatively higher chlorophyll concentration was observed when broccoli were treated with hot water. Among these heat treatments, immersion in hot water for 4 min at 45 °C was the most effective for maintaining the quality of harvested broccoli heads.

  2. Novel Method for Measuring the Heat Collection Rate and Heat Loss Coefficient of Water-in-Glass Evacuated Tube Solar Water Heaters Based on Artificial Neural Networks and Support Vector Machine

    Directory of Open Access Journals (Sweden)

    Zhijian Liu

    2015-08-01

    Full Text Available The determinations of heat collection rate and heat loss coefficient are crucial for the evaluation of in service water-in-glass evacuated tube solar water heaters. However, the direct determination requires complex detection devices and a series of standard experiments, which also wastes too much time and manpower. To address this problem, we propose machine learning models including artificial neural networks (ANNs and support vector machines (SVM to predict the heat collection rate and heat loss coefficient without a direct determination. Parameters that can be easily obtained by “portable test instruments” were set as independent variables, including tube length, number of tubes, tube center distance, heat water mass in tank, collector area, final temperature and angle between tubes and ground, while the heat collection rate and heat loss coefficient determined by the detection device were set as dependent variables respectively. Nine hundred fifteen samples from in-service water-in-glass evacuated tube solar water heaters were used for training and testing the models. Results show that the multilayer feed-forward neural network (MLFN with 3 nodes is the best model for the prediction of heat collection rate and the general regression neural network (GRNN is the best model for the prediction of heat loss coefficient due to their low root mean square (RMS errors, short training times, and high prediction accuracies (under the tolerances of 30%, 20%, and 10%, respectively.

  3. Modeling of Possible Conditions for Origin of First Organic Forms in hot Mineral Water

    OpenAIRE

    Ignat Ignatov; Oleg Mosin

    2014-01-01

    The composition of water, its temperature and pH value was analyzed in experiments with modelling of primary hydrosphere and possible conditions for origin of first organic forms in hot mineral water. For this aim the authors performed experiments with hot mineral and seawater from Bulgaria by IR-spectrometry (DNES-method). As model systems were used cactus juice of Echinopsis pachanoi and Mediterranean jellyfish Cotylorhiza tuberculata. It was considered the reactions of condensation and deh...

  4. Hot water epilepsy: Phenotype and single photon emission computed tomography observations

    OpenAIRE

    Mehul Patel; Parthasarathy Satishchandra; Hanumanthapura Aravinda; Bharath, Rose D.; Sanjib Sinha

    2014-01-01

    We studied the anatomical correlates of reflex hot water epilepsy (HWE) using multimodality investigations viz. magnetic resonance imaging (MRI), electroencephalography (EEG), and single photon emission computed tomography (SPECT). Five men (mean age: 27.0 ΁ 5.8 years) with HWE were subjected to MRI of brain, video-EEG studies, and SPECT scan. These were correlated with phenotypic presentations. Seizures could be precipitated in three patients with pouring of hot water over the head and semio...

  5. Solar domestic hot water system installed at Texas City, Texas. Final report

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-12-01

    The Solar Energy System located at LaQuinta Motor Inn, Texas City, Texas was designed to supply 63% of the total hot water load. The Solar Energy System consists of a 2100 square foot Raypack Liquid Flat Plate Collector Subsystem and a 2500 gallon storage subsystem circulating hot water producing 3.67 x 10/sup 8/ Btu/y. Abstracts from the site files, specification references, drawings, installation, operation and maintenance instructions are included.

  6. The Use of Solar Energy for Preparing Domestic Hot Water in a Multi-Storey Building

    OpenAIRE

    Giedrius Šiupšinskas; Solveiga Adomėnaitė

    2012-01-01

    The article analyses the possibilities of solar collectors used for a domestic hot water system and installed on the roofs of modernized multi-storey buildings under the existing climate conditions. A number of combinations of flat plate and vacuum solar collectors with accumulation tank systems of various sizes have been examined. Heat from the district heating system is used as an additional heat source for preparing domestic hot water. The paper compares calculation results of energy and e...

  7. Recovery of energy from geothermal brine and other hot water sources

    Science.gov (United States)

    Wahl, III, Edward F.; Boucher, Frederic B.

    1981-01-01

    Process and system for recovery of energy from geothermal brines and other hot water sources, by direct contact heat exchange between the brine or hot water, and an immiscible working fluid, e.g. a hydrocarbon such as isobutane, in a heat exchange column, the brine or hot water therein flowing countercurrent to the flow of the working fluid. The column can be operated at subcritical, critical or above the critical pressure of the working fluid. Preferably, the column is provided with a plurality of sieve plates, and the heat exchange process and column, e.g. with respect to the design of such plates, number of plates employed, spacing between plates, area thereof, column diameter, and the like, are designed to achieve maximum throughput of brine or hot water and reduction in temperature differential at the respective stages or plates between the brine or hot water and the working fluid, and so minimize lost work and maximize efficiency, and minimize scale deposition from hot water containing fluid including salts, such as brine. Maximum throughput approximates minimum cost of electricity which can be produced by conversion of the recovered thermal energy to electrical energy.

  8. Hot spots and hot moments in riparian zones: potential for improved water quality management

    Science.gov (United States)

    Despite considerable heterogeneity over space and time, biogeochemical and hydrological processes in riparian zones regulate contaminant movement to receiving waters and often mitigate the impact of upland sources of contaminants on water quality. Recently, these heterogeneous processes have been co...

  9. Water and feed consumption in broiler birds during a typical hot ...

    African Journals Online (AJOL)

    This study investigates the variability in feed and water consumption in broiler birds during a typical hot weather condition in Akure, Nigeria. Feed and water consumption as well as air temperature and relative humidity were monitored and the relationship between them was analyzed. The results showed that the daily water ...

  10. Solar hot water system installed at Days Inn Motel, Jacksonville, Florida

    Science.gov (United States)

    1980-01-01

    The solar system was designed to provide 65 percent of the hot water demand. Water in the liquid flat plate collector (900 square feet) system automatically drains into the 1000 gallon lined and vented steel storage tank when the pump is not running. Heat is transferred from storage to Domestic Hot Water (DHW) tanks through a tube and shell heat exchanger. A circulating pump between the DHW tanks and heat exchanger enables solar heated water to help make up DHW standby losses. All pumps are controlled by differential temperature.

  11. Thermal performance analysis of a flat heat pipe working with carbon nanotube-water nanofluid for cooling of a high heat flux heater

    Science.gov (United States)

    Arya, A.; Sarafraz, M. M.; Shahmiri, S.; Madani, S. A. H.; Nikkhah, V.; Nakhjavani, S. M.

    2017-10-01

    Experimental investigation on the thermal performance of a flat heat pipe working with carbon nanotube nanofluid is conducted. It is used for cooling a heater working at high heat flux conditions up to 190 kW/m2. The heat pipe is fabricated from aluminium and is equipped with rectangular fin for efficient cooling of condenser section. Inside the heat pipe, a screen mesh was inserted as a wick structure to facilitate the capillary action of working fluid. Influence of different operating parameters such as heat flux, mass concentration of carbon nanotubes and filling ratio of working fluid on thermal performance of heat pipe and its thermal resistance are investigated. Results showed that with an increase in heat flux, the heat transfer coefficient in evaporator section of the heat pipe increases. For filling ratio, however, there is an optimum value, which was 0.8 for the test heat pipe. In addition, CNT/water enhanced the heat transfer coefficient up to 40% over the deionized water. Carbon nanotubes intensified the thermal performance of wick structure by creating a fouling layer on screen mesh structure, which changes the contact angle of liquid with the surface, intensifying the capillary forces.

  12. New Design Heaters Using Tubes Finned by Deforming Cutting Method

    Science.gov (United States)

    Zubkov, N. N.; Nikitenko, S. M.; Nikitenko, M. S.

    2017-10-01

    The article describes the results of research aimed at selecting and assigning technological processing parameters for obtaining outer fins of heat-exchange tubes by the deformational cutting method, for use in a new design of industrial water-air heaters. The thermohydraulic results of comparative engineering tests of new and standard design air-heaters are presented.

  13. Research on temperature control and influence of the vacuum tubes with inserted tubes solar heater

    Science.gov (United States)

    Xiao, L. X.; He, Y. T.; Hua, J. Q.

    2017-11-01

    A novel snake-shape vacuum tube with inserted tubes solar collector is designed in this paper, the heat transfer characteristics of the collector are analyzed according to its structural characteristics, and the influence of different working temperature on thermal characteristics of the collector is studied. The solar water heater prototype consisting of 14 vacuum tubes with inserted tubes is prepared, and the hot water storage control subsystem is designed by hysteresis comparison algorithm. The heat characteristic of the prototype was experimentally studied under hot water output temperature of 40-45°C, 50-55°C and 60-65°C. The daily thermal efficiency was 64%, 50% and 46%, respectively. The experimental results are basically consistent with the theoretical analysis.

  14. Interactive effects of temperature, organic carbon, and pipe material on microbiota composition and Legionella pneumophila in hot water plumbing systems.

    Science.gov (United States)

    Proctor, Caitlin R; Dai, Dongjuan; Edwards, Marc A; Pruden, Amy

    2017-10-04

    Several biotic and abiotic factors have been reported to influence the proliferation of microbes, including Legionella pneumophila, in hot water premise plumbing systems, but their combined effects have not been systematically evaluated. Here, we utilize simulated household water heaters to examine the effects of stepwise increases in temperature (32-53 °C), pipe material (copper vs. cross-linked polyethylene (PEX)), and influent assimilable organic carbon (0-700 μg/L) on opportunistic pathogen gene copy numbers and the microbiota composition, as determined by quantitative polymerase chain reaction and 16S rRNA gene amplicon sequencing. Temperature had an overarching influence on both the microbiota composition and L. pneumophila numbers. L. pneumophila peaked at 41 °C in the presence of PEX (1.58 × 10 5 gene copies/mL). At 53 °C, L. pneumophila was not detected. Several operational taxonomic units (OTUs) persisted across all conditions, accounting for 50% of the microbiota composition from 32 to 49 °C and 20% at 53 °C. Pipe material most strongly influenced microbiota composition at lower temperatures, driven by five to six OTUs enriched with each material. Copper pipes supported less L. pneumophila than PEX pipes (mean 2.5 log 10 lower) at temperatures ≤ 41 °C, but showed no difference in total bacterial numbers. Differences between pipe materials diminished with elevated temperature, probably resulting from decreased release of copper ions. At temperatures ≤ 45 °C, influent assimilable organic carbon correlated well with total bacterial numbers, but not with L. pneumophila numbers. At 53 °C, PEX pipes leached organic carbon, reducing the importance of dosed organic carbon. L. pneumophila numbers correlated with a Legionella OTU and a Methylophilus OTU identified by amplicon sequencing. Temperature was the most effective factor for the control of L. pneumophila, while microbiota composition shifted with each stepwise temperature

  15. Alternative for Summer Use of Solar Air Heaters in Existing Buildings

    Directory of Open Access Journals (Sweden)

    Sergio L. González-González

    2017-07-01

    Full Text Available Among solar thermal technologies for indoor heating, solar air heaters (SAH are appealing for implementation on existing buildings due to their simplicity, fewer risks related to the working fluid, and possible independence from the building structure. However, existing research work mainly focuses on winter use and still fails in providing effective solutions for yearly operation, which would enhance their interest. With the aim of analysing an alternative summer use, this work firstly characterises a double channel-single pass solar air collector through experimentation. From the obtained results, modelling and simulation tasks have been conducted to evaluate the possibilities of using hot air, provided by the SAH, while operating under summer conditions within a closed loop, to feed an air-to-water heat exchanger for domestic hot water (DHW production. The system is studied through simulation under two different configurations for a case study in Valladolid (Spain, during the period from May to September for different airflows in the closed loop. Results show that daily savings can vary from 27% to 85% among the different operating conditions; a configuration where make-up water is fed to the heat exchanger being preferable, with a dedicated water tank for the solar heated water storage of the minimum possible volume. The more favourable results for the harshest months highlight the interest of extending the use of the solar air heaters to the summer period.

  16. Coaxial Electric Heaters

    Science.gov (United States)

    Strekalov, Dmitry; Matsko, Andrey; Savchenkov, Anatoliy; Maleki, Lute

    2008-01-01

    Coaxial electric heaters have been conceived for use in highly sensitive instruments in which there are requirements for compact heaters but stray magnetic fields associated with heater electric currents would adversely affect operation. Such instruments include atomic clocks and magnetometers that utilize heated atomic-sample cells, wherein stray magnetic fields at picotesla levels could introduce systematic errors into instrument readings. A coaxial electric heater is essentially an axisymmetric coaxial cable, the outer conductor of which is deliberately made highly electrically resistive so that it can serve as a heating element. As in the cases of other axisymmetric coaxial cables, the equal magnitude electric currents flowing in opposite directions along the inner and outer conductors give rise to zero net magnetic field outside the outer conductor. Hence, a coaxial electric heater can be placed near an atomic-sample cell or other sensitive device. A coaxial electric heater can be fabricated from an insulated copper wire, the copper core of which serves as the inner conductor. For example, in one approach, the insulated wire is dipped in a colloidal graphite emulsion, then the emulsion-coated wire is dried to form a thin, uniform, highly electrically resistive film that serves as the outer conductor. Then the film is coated with a protective layer of high-temperature epoxy except at the end to be electrically connected to the power supply. Next, the insulation is stripped from the wire at that end. Finally, electrical leads from the heater power supply are attached to the exposed portions of the wire and the resistive film. The resistance of the graphite film can be tailored via its thickness. Alternatively, the film can be made from an electrically conductive paint, other than a colloidal graphite emulsion, chosen to impart the desired resistance. Yet another alternative is to tailor the resistance of a graphite film by exploiting the fact that its resistance

  17. Measured electric hot water standby and demand loads from Pacific Northwest homes

    Energy Technology Data Exchange (ETDEWEB)

    Pratt, R.G.; Ross, B.A.

    1991-11-01

    The Bonneville Power Administration began the End-Use Load and Consumer Assessment Program (ELCAP) in 1983 to obtain metered hourly end-use consumption data for a large sample of new and existing residential and commercial buildings in the Pacific Northwest. Loads and load shapes from the first 3 years of data fro each of several ELCAP residential studies representing various segments of the housing population have been summarized by Pratt et al. The analysis reported here uses the ELCAP data to investigate in much greater detail the relationship of key occupant and tank characteristics to the consumption of electricity for water heating. The hourly data collected provides opportunities to understand electricity consumption for heating water and to examine assumptions about water heating that are critical to load forecasting and conservation resource assessments. Specific objectives of this analysis are to: (A) determine the current baseline for standby heat losses by determining the standby heat loss of each hot water tank in the sample, (B) examine key assumptions affecting standby heat losses such as hot water temperatures and tank sizes and locations, (C) estimate, where possible, impacts on standby heat losses by conservation measures such as insulating tank wraps, pipe wraps, anticonvection valves or traps, and insulating bottom boards, (D) estimate the EF-factors used by the federal efficiency standards and the nominal R-values of the tanks in the sample, (E) develop estimates of demand for hot water for each home in the sample by subtracting the standby load from the total hot water load, (F) examine the relationship between the ages and number of occupants and the hot water demand, (G) place the standby and demand components of water heating electricity consumption in perspective with the total hot water load and load shape.

  18. The analysis of unit costs of preparing hot water for various sources of heat

    Directory of Open Access Journals (Sweden)

    Mazur Aleksandra

    2017-01-01

    Full Text Available The article presents an analysis of energy consumption and the cost of its production by the systems of supply of hot water depending on the applied heat sources and destination of a building. The calculations have taken into account the efficiency of the adopted installation solutions that have a direct impact on energy consumption. The following parameters have been determined: the size of the seasonal demand for hot water, an annual amount of fuel needed to its production and annual operating costs. The calculations have been performed for residential buildings and public buildings, whilst maintaining the same usable space. The aim of the article is to determine the rate of the amount of fuel, needed to heat to the desired temperature, a unit volume of water depending on the type of heat source and destination of a premises. For the adopted variants of installation, the ratio of production costs of unit volume of hot water has been also determined. The indicators of the fuel amount and the cost of hot water pointed out in the article may be one of the criteria for selection of an effective system for the preparation of hot water.

  19. Integration of Space Heating and Hot Water Supply in Low Temperature District Heating

    DEFF Research Database (Denmark)

    Elmegaard, Brian; Ommen, Torben Schmidt; Markussen, Michael

    2014-01-01

    pipes, where the water is at the highest temperature. The heat loss may be lowered by decreasing the temperatures in the network for which reason low temperature networks are proposed as a low loss solution for future district heating. However, the heating demand of the consumers involve both domestic...... hot water and space heating. Space heating may be provided at low temperature in modern low energy buildings. Domestic hot water, however, needs to reach sufficient temperatures to avoid growth of legionella bacteria. If the network temperature is below the temperature demand, supplementary heating...... is required by the consumer. In the present paper we study conventional district heating at different temperature levels and compare the energy efficiency, the exergetic efficiency and annual heating cost to solutions that utilize electricity for supplementary heating of domestic hot water in low temperature...

  20. Solar heating and hot water system installed at Cherry Hill, New Jersey. [Hotels

    Energy Technology Data Exchange (ETDEWEB)

    1979-05-16

    The solar heating and hot water system installed in existing buildings at the Cherry Hill Inn in Cherry Hill, New Jersey is described in detail. The system went into operation November 8, 1978 and is expected to furnish 31.5% of the overall heating load and 29.8% of the hot water load. The collectors are General Electric Company liquid evacuated tube type. The storage system is an above ground insulated steel water tank with a capacity of 7,500 gallons.

  1. Hot Water Dipping in Northern Germany- on farm results after four years of scientific work

    OpenAIRE

    Maxin, Peter (Versuchs- und Beratungszentrum Jork); Fieger-Metag, Nicole; Benduhn, Bastian; Kruse, Petra; Heyne, Peter

    2006-01-01

    In general, organic grown apples (Malus x domestica Borkh.) are not treated with chemical fungicides to pre-vent storage decay and these fruits may suffer up to 30% decay during storage. Preliminary experiments had shown that hot water dipping of apples may be an alternative. To inhibit Gloeosporium rot (Pezicula alba, P. malicortis) water temperature may be of about 50°C and dipping time from 60 sec up to 240 sec. The objec-tive was to determinate the suitable hot water treatment that preven...

  2. Solar energy meets 50 pecent of motel hot water needs--Key West, Florida

    Science.gov (United States)

    1981-01-01

    Final report describes domestic water preheat installed in 148 room motel. Equipment meets 50 percent of needs when motel is 100 percent occupied; equivalently, it supplies 100 percent of hot water when occupancy is 50 percent. System consists of 1,400 square feet of flat plate liquid solar collectors, storage tanks, pump, controller, and hardware.

  3. Evaluation of the impact of hot water treatment on the sensory quality of fresh tomatoes

    Science.gov (United States)

    Minimizing the effects of chilling injury during shelf-life is important for maintaining the sensory quality of fresh tomato fruit. Postharvest hot water treatments within certain limits of exposure time and water temperature have been shown to increase the resistance of tomatoes to chilling injury....

  4. Effect of Hot water and dilute acid pretreatment on the chemical properties of liquorice root

    Directory of Open Access Journals (Sweden)

    zahra takzare

    2016-06-01

    Full Text Available Abstract In this study, the liquorice root (Glycyrrhiza glabra that was extracted in the factory in Kerman province, pre-hydrolyzed and then chemical compositions (Extractives, Lignin content, Holocellulose percent, the hydrolysis process yield and weight loss of the waste was measured. Pre-hydrolysis process was done on the above mentioned waste by hot water, hot water followed by 0.5 percent sulfuric acid and also alone sulfuric acid with different concentrations (0.5, 1, 1.5 and 2 percent The samples were pre-hydrolyzed in hot water at 150 °C and 30, 60 and 90 minutes as well as in the mixture of hot water and 0.5 % sulfuric acid at 150 °C and 60 minutes and also in pure sulfuric acid, at 130 °C and at 60 minutes. The results showed that the pre-hydrolyzed treatment with hot water in 60 minutes had been favorable performance in the respect of weight loss, lignin content and holocellulose percent. Also, in the case of pre-treatment including sulfuric acid, 2% dose can be good selected option in term of maximum holocellulose percent and minimum lignin content so that it can be suggested to produce higher value-added products such as bioethanol from licorice root bid.

  5. Application of waterproof breathable fabric in thermal protective clothing exposed to hot water and steam

    Science.gov (United States)

    Su, Y.; Li, R.; Song, G.; Li, J.

    2017-10-01

    A hot water and steam tester was used to examine thermal protective performance of waterproof and breathable fabric against hot water and steam hazards. Time to cause skin burn and thermal energy absorbed by skin during exposure and cooling phases was employed to characterize the effect of configuration, placing order and properties of waterproof and breathable fabric on the thermal protective performance. The difference of thermal protective performance due to hot water and steam hazards was discussed. The result showed that the configuration of waterproof and breathable fabric presented a significant effect on the thermal protective performance of single- and double-layer fabric system, while the difference between different configurations in steam hazard was greater than that in hot water hazard. The waterproof and breathable fabric as outer layer provided better protection than that as inner layer. Increasing thickness and moisture regain improved the thermal protective performance of fabric system. Additionally, the thermal energy absorbed by skin during the cooling phase was affected by configuration, thickness and moisture regain of fabric. The findings will provide technical data to improve performance of thermal protective clothing in hot water and steam hazards.

  6. Modeling DBPs formation in drinking water in residential plumbing pipes and hot water tanks.

    Science.gov (United States)

    Chowdhury, Shakhawat; Rodriguez, Manuel J; Sadiq, Rehan; Serodes, Jean

    2011-01-01

    Disinfection byproducts (DBPs) in municipal supply water are a concern because of their possible risks to human health. Risk assessment studies often use DBP data in water distribution systems (WDS). However, DBPs in tap water may be different because of stagnation of the water in plumbing pipes (PP) and heating in hot water tanks (HWT). This study investigated occurrences and developed predictive models for DBPs in the PP and the HWT of six houses from three municipal water systems in Quebec (Canada) in a year-round study. Trihalomethanes (THMs) in PP and HWT were observed to be 1.4-1.8 and 1.9-2.7 times the THMs in the WDS, respectively. Haloacetic acid (HAAs) in PP and HWT were observed to be variable (PP/WDS = 0.23-2.24; HWT/WDS = 0.53-2.61). Using DBPs occurrence data from these systems, three types of linear models (main factors; main factors, interactions and higher orders; logarithmic) and two types of nonlinear models (three parameters Logistic and four parameters Weibull) were investigated to predict DBPs in the PP and HWT. Significant factors affecting DBPs formation in the PP and HWT were identified through numerical and graphical techniques. The R(2) values of the models varied between 0.77 and 0.96, indicating excellent predictive ability for THMs and HAAs in the PP and the HWT. The models were found to be statistically significant. The models were validated using additional data. These models can be used to predict DBPs increase from WDS (water entry point of house) to the PP and HWT, and could thereby help gain a better understanding of human exposure to DBPs and their associated risks. Copyright © 2010 Elsevier Ltd. All rights reserved.

  7. TOUGH2 model of the G-tunnel heater test

    Energy Technology Data Exchange (ETDEWEB)

    Ho, C.K.; Eaton, R.R. [Sandia National Lab., Albuquerque, NM (United States)

    1995-12-01

    An experiment designed to observe water migration under non-isothermal conditions in welded tuff was performed in 1980 in the welded portion of the Grouse Canyon Member in the U12g tunnel (G-tunnel) at Rainier Mesa. Significant amounts of water were observed to migrate towards a heated hole bored into the welded tuff. The water migration was attributed to vapor phase diffusion, but other processes such as gravity driven flow were not considered and may have contributed significantly to the observed water migration. The modeling studies presented here address processes of water migration near heated regions in partially saturated tuff. The multiphase, non-isothermal numerical code TOUGH2 was used to model the G-Tunnel heater experiment. The numerical simulation consisted of 10 days of heating at 1000 W. Temperatures, liquid saturations, gas pressures, gas and liquid velocities, and vapor mass fractions were recorded to determine the processes affecting water migration. Results of the simulation indicated that water migration near heated tuffaceous rock involves a combination of processes. Gas-phase advection and diffusion transported water vapor that was evaporated near the heater toward outer regions. Water vapor condensed in cooler regions away from the heater, increasing the saturations. As liquid water accumulated in the heater borehole, capillary suction pulled some of the liquid toward the drier heated region while gravity drained some of the liquid away from the heater. In natural systems, high permeability fractures could mimic the role of the heater hole.

  8. Solar hot water system installed at Day's Lodge, Atlanta, Georgia

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-09-01

    The solar energy hot water system installed in the Days Inns of America, Inc., Day's Lodge I-85 and Shallowford Road, NE Atlanta, Georgia is described. This system is one of eleven systems planned under this grant and was designed to provide for 81% of the total hot water demand. There are two separate systems, each serving one building of the lodge (total of 65 suites). The entire system contains only potable city water. The 1024 square feet of Grumman Sunstream Model 332 liquid flat plate collectors and the outside piping drains whenever the collector plates approach freezing or when power is interrupted. Solar heated water from the two above ground cement lined steel tanks (1000 gallon tank) is drawn into the electric domestic hot water (DHW) tanks as hot water is drawn. Electric resistance units in the DHW tanks top off the solar heated water, if needed, to reach thermostat setting. Operation of this system was begun in August, 1979. The solar components were partly funded ($18,042 of $36,084 cost) by the Department of Energy.

  9. Extraction of steviol glycosides from fresh Stevia using acidified water; comparison to hot water extraction, including purification

    NARCIS (Netherlands)

    Kootstra, A.M.J.; Huurman, Sander

    2017-01-01

    This report describes a practical comparison of an acidified water extraction of freshly harvested Stevia
    plants (the NewFoss method) to the hot water extraction of dried Stevia plants, the industry standard. Both
    extracts are subsequently purified using lab-/bench scale standard industrial

  10. Improvements in Thermal Performance of Mango Hot-water Treatment Equipments: Data Analysis, Mathematical Modelling and Numerical-computational Simulation

    OpenAIRE

    Mendoza Orbegoso, Elder M.; Paul Villar-Yacila; Daniel Marcelo; Justo Oquelis

    2017-01-01

    Mango is one of the most popular and best paid tropical fruits in worldwide markets, its exportation is regulated within a phytosanitary quality control for killing the “fruit fly”. Thus, mangoes must be subject to hot-water treatment process that involves their immersion in hot water over a period of time. In this work, field measurements, analytical and simulation studies are developed on available hot-water treatment equipment called “Original” that only complies wi...

  11. Integration of space heating and hot water supply in low temperature district heating

    DEFF Research Database (Denmark)

    Elmegaard, Brian; Ommen, Torben Schmidt; Markussen, Michael

    2016-01-01

    of the consumers involves both domestic hot water and space heating. Space heating may be provided at low temperature in low energy buildings. Domestic hot water, however, needs sufficient temperatures to avoid growth of legionella. If the network temperature is below the demand temperature, supplementary heating......District heating may supply many consumers efficiently, but the heat loss from the pipes to the ground is a challenge. The heat loss may be lowered by decreasing the network temperatures for which reason low temperature networks are proposed for future district heating. The heating demand...... is required by the consumer. We study conventional district heating at different temperatures and compare the energy and exergetic efficiency and annual heating cost to solutions that utilize electricity for supplementary heating of domestic hot water in low temperature district heating. This includes direct...

  12. Physicochemical and phytochemical properties of cold and hot water extraction from Hibiscus sabdariffa.

    Science.gov (United States)

    Ramirez-Rodrigues, Milena M; Plaza, Maria L; Azeredo, Alberto; Balaban, Murat O; Marshall, Maurice R

    2011-04-01

    Hibiscus cold (25 °C) and hot (90 °C) water extracts were prepared in various time-temperature combinations to determine equivalent extraction conditions regarding their physicochemical and phytochemical properties. Equivalent anthocyanins concentration was obtained at 25 °C for 240 min and 90 °C for 16 min. Total phenolics were better extracted with hot water that also resulted in a higher antioxidant capacity in these extracts. Similar polyphenolic profiles were observed between fresh and dried hibiscus extracts. Hibiscus acid and 2 derivatives were found in all extracts. Hydroxybenzoic acids, caffeoylquinic acids, flavonols, and anthocyanins constituted the polyphenolic compounds identified in hibiscus extracts. Two major anthocyanins were found in both cold and hot extracts: delphynidin-3-sambubioside and cyanidin-3-sambubioside. In general, both cold and hot extractions yielded similar phytochemical properties; however, under cold extraction, color degradation was significantly lower and extraction times were 15-fold longer. Hibiscus beverages are prepared from fresh or dried calyces by a hot extraction and pasteurized, which can change organoleptic, nutritional, and color attributes. Nonthermal technologies such as dense phase carbon dioxide may maintain their fresh-like color, flavor, and nutrients. This research compares the physicochemical and phytochemical changes resulting from a cold and hot extraction of fresh and dried hibiscus calyces and adds to the knowledge of work done on color, quality attributes, and antioxidant capacity of unique tropical products. In addition, the research shows how these changes could lead to alternative nonthermal processes for hibiscus.

  13. Experimental verification of a method for estimating energy for domestic hot water production in a 2-stage district heating substation

    Energy Technology Data Exchange (ETDEWEB)

    Yliniemi, Kimmo; Delsing, Jerker; van Deventer, Jan [Luleaa University of Technology, Department of Computer Science and Electrical Engineering, Division EISLAB, 971 87 Luleaa (Sweden)

    2009-02-15

    In this paper we compare our estimate of energy consumption for domestic hot water production in a building with the measured value. The energy consumption for hot water production is estimated from the measured total power consumption. The estimation method was developed using computer simulations, and it is based on the assumption that hot water production causes rapid and detectable changes in power consumption. A comparison of our estimates with measurements indicates that the uncertainty in estimation of hot water energy consumption is {+-}10%. Thus, the estimate is comparable to class 3 energy meter measurements, which have an uncertainty of {+-}2-10%. (author)

  14. 10 CFR Appendix E to Subpart B of... - Uniform Test Method for Measuring the Energy Consumption of Water Heaters

    Science.gov (United States)

    2010-01-01

    ..., total number of draws during the first-hour rating test Q total fossil fuel and/or electric energy... equal to the nominal value of 77 °F (42.8 °C) Q r energy consumption of fossil fuel or heat pump water... fossil fueled and/or electric energy consumed from the beginning of the first draw to the thermostat (or...

  15. Research on a Household Dual Heat Source Heat Pump Water Heater with Preheater Based on ASPEN PLUS

    Directory of Open Access Journals (Sweden)

    Xiang Gou

    2016-12-01

    Full Text Available This article proposes a dual heat source heat pump bathroom unit with preheater which is feasible for a single family. The system effectively integrates the air source heat pump (ASHP and wastewater source heat pump (WSHP technologies, and incorporates a preheater to recover shower wastewater heat and thus improve the total coefficient of performance (COP of the system, and it has no electric auxiliary heating device, which is favorable to improve the security of the system operation. The process simulation software ASPEN PLUS, widely used in the design and optimization of thermodynamic systems, was used to simulate various cases of system use and to analyze the impact of the preheater on the system. The average COP value of a system with preheater is 6.588 and without preheater it is 4.677. Based on the optimization and analysis, under the standard conditions of air at 25 °C, relative humidity of 70%, wastewater at 35 °C, wastewater flow rate of 0.07 kg/s, tap water at 15 °C, and condenser outlet water temperature at 50 °C, the theoretical COP of the system can reach 9.784 at an evaporating temperature of 14.96 °C, condensing temperature of 48.74 °C, and preheated water temperature of 27.19 °C.

  16. Analysis, Modeling and Optimum Design of Solar Domestic Hot Water Systems

    DEFF Research Database (Denmark)

    Qin, Lin

    1999-01-01

    This study focus on the analysis, modeling and simulation of solar domestic hot water(DHW) systems. Problems related to the system operation such as input weather data and hot water load conditions are also investigated.In order to investigate the heat loss as part of the total heat load, dynamic...... model of distribution network is developed and simulations are carried out for typical designed circulation type of distribution networks. For dynamic simulation of thermosyphon and drain-back solar DHW systems, thermosyphon loop model and drain-back tank model are put forward. Based on the simulations...

  17. Solar Energy for Domestic Hot Water: Case Studies in Sisimiut 1999-2005

    DEFF Research Database (Denmark)

    Reimann, Gregers Peter

    2005-01-01

    Two pioneer solar domestic hot water systems were installed at Bygge- og Anlægsskolen in Sisimiut in 1999 and 2000. Detailed measurements of energy flows and solar radiation incl. snow reflectance has been undertaken for both plants. Since August 2004 data logging of the measurements was made...... available online on the website www.arcticsolar.com. Measurements show that solar plant 1 and 2 cover 22% and 23%, respectively, of the energy spent for domestic hot water heating. This paper summarises the findings from the past 5 years....

  18. Pseudo hot water epilepsy: A pilot study on behavioral psychotherapeutic management.

    Science.gov (United States)

    Venkataramiah, V; Ghorpade, V A P

    2013-04-01

    Diagnostic accuracy of Hot Water Epilepsy (HWE) on history alone was observed to be less satisfactory by the first author while managing such patients psychologically. To confirm this observation this pilot study was planned. Symptoms as reported by the patient was confirmed by the two authors in the wards by giving them Hot Water Head Bath. Following this they were subjected to behavioral Psychotherapeutic treatment to relieve them from their distressful symptoms. Confirmed the hypothesis and it was concluded that by witnessing the symptoms of HWE by the treating doctor would improve the outcome of any treatment.

  19. Radiological performance of hot water layer system in open pool type reactor

    Directory of Open Access Journals (Sweden)

    Amr Abdelhady

    2013-06-01

    Full Text Available The paper presents the calculated dose rate carried out by using MicroShield code to show the importance of hot water layer system (HWL in 22 MW open pool type reactor from the radiation protection safety point of view. The paper presents the dose rate profiles over the pool surface in normal and abnormal operations of HWL system. The results show that, in case of losing the hot water layer effect, the radiation dose rate profiles over the pool surface will increase from values lower than the worker permissible dose limits to values very higher than the permissible dose limits.

  20. Experimental analysis on the use of condensing boilers for centralized production of domestic hot water

    Energy Technology Data Exchange (ETDEWEB)

    Cirillo, E.; Lazzarin, R.; Piccininni, F.; Caliari, R. (Bari Univ. (Italy). Ist. di Fisica Tecnica ed Impianti Termotecnici)

    1988-11-01

    The monthly performance of pulse combustion condensing boilers has been studied. The boilers are utilized in a plant for the centralized production of domestic hot water. The heating capacity is 112 kW with a daily production of 15 cubic meter of hot waters at 60 degrees centigrade. The analysis has shown the very good seasonal performance of the boilers even without a suitable plant design. The great importance of the heat distribution system has been outlined in order to reach good overall performance.

  1. Alternative Solution for Consumption Hot Water Recirculation for the Civil Buildings

    Directory of Open Access Journals (Sweden)

    Theodor Mateescu

    2007-01-01

    Full Text Available The sanitary comfort and the effective cost of maintenance in the civil buildings (block of flats are badly affected by the absence of the consumption hot water recirculation. From the technical point of view, the classical solution imposes the doubling of the transport and distribution pipes on the entire route, between the source and the consumption points. The materialization of the solution requires important financial investment, discouraging most of the time and the postponement of the problem solving with important consequences. This paper proposes an alternative technical solution which limits to a minimum the intervention, only in the interior hot water distribution system.

  2. Too Hot to Handle: Climate Change and Agricultural Water Use

    Directory of Open Access Journals (Sweden)

    Denise Fort

    2011-10-01

    Full Text Available The world faces enormous challenges in responding to looming crises in food and water. Responding to this challenge will require flexibility; such flexibility may be impeded by legal institutions. This paper looks at the western United States and discusses the role of irrigated agriculture in that region. Because of climate change, a growing population, declining groundwater, the need to protect ecosystems and other conflicts, the author suggests that all water uses, including long-standing agricultural water rights, need to be examined in light of these changes. Legal systems have tended to serve the status quo, but perhaps the law can help facilitate this re-examination.

  3. The effect of efficiency standards on water use and water heating energy use in the US: A detailed end-use treatment

    Energy Technology Data Exchange (ETDEWEB)

    Koomey, J.G.; Dunham, C.; Lutz, J.D.

    1994-05-01

    Water heating is an important end-use, accounting for roughly 16% of total primary energy consumption in the US residential sector. Recently enacted efficiency standards on water heaters and hot water-using equipment (e.g., dishwashers, clothes washers, showerheads, and faucets) will substantially affect the energy use of water heaters in the future. Assessment of current and future utility programs and government policies requires that regulators, resource planners, and forecasters understand the effects of these regulations. In order to quantify these impacts, this paper presents a detailed end-use breakdown of household hot and cold water use developed for the US Department of Energy. This breakdown is based on both previous studies and new data and analysis. It is implemented in a spreadsheet forecasting framework, which allows significant flexibility in specifying end-use demands and linkages between water heaters and hot water-using appliances. We disaggregate total hot and cold water use (gallons per day) into their component parts: showers, baths, faucets (flow dominated and volume dominated), toilets, landscaping/other, dishwashers, and clotheswashers. We then use the end-use breakdown and data on equipment characteristics to assess the impacts of current efficiency standards on hot water use and water heater energy consumption.

  4. Solar heating and hot water system installed at office building, One Solar Place, Dallas, Texas. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1980-06-01

    This document is the Final Report of the Solar Energy System Installed at the First Solar Heated Office Building, One Solar Place, Dallas, Texas. The Solar System was designed to provide 87 percent of the space heating needs, 100 percent of the potable hot water needs and is sized for future absorption cooling. The collection subsystem consists of 28 Solargenics, series 76, flat plate collectors with a total area of 1596 square feet. The solar loop circulates an ethylene glycol-water solution through the collectors into a hot water system heat exchanger. The hot water storage subsystem consists of a heat exchanger, two 2300 gallon concrete hot water storage tanks with built in heat exchangers and a back-up electric boiler. The domestic hot water subsystem sends hot water to the 10,200 square feet floor area office building hot water fixtures. The building cold water system provides make-up to the solar loop, the heating loop, and the hot water concrete storage tanks. The design, construction, cost analysis, operation and maintenance of the solar system are described. The system became operational July 11, 1979.

  5. Imaging the Extended Hot Hydrogen Exosphere at Mars to Determine the Water Escape Rate

    Science.gov (United States)

    Bhattacharyya, Dolon

    2017-08-01

    ACS SBC imaging of the extended hydrogen exosphere of Mars is proposed to identify the hot hydrogen population present in the exosphere of Mars. Determining the characteristics of this population and the underlying processes responsible for its production are critical towards constraining the escape flux of H from Mars, which in turn is directly related to the water escape history of Mars. Since the hot atoms appear mainly at high altitudes, these observations will be scheduled when Mars is far from Earth allowing us to image the hot hydrogen atoms at high altitudes where they dominate the population. The altitude coverage by HST will extend beyond 30,000 km or 8.8 Martian radii in this case, which makes it perfect for this study as orbiting spacecraft remain at low altitudes (MAVEN apoapse is 6000 km) and cannot separate hot atoms from the thermal population at those altitudes. The observations will also be carried out when Mars is near aphelion, the atmospheric temperature is low, and the thermal population has a small scale height, allowing the clear characterization of the hot hydrogen layer. Another advantage of conducting this study in this cycle is that the solar activity is near its minimum, allowing us to discriminate between changes in the hot hydrogen population from processes taking place within the atmosphere of Mars and changes due to external drivers like the solar wind, producing this non-thermal population. This proposal is part of the HST UV initiative.

  6. Input/output test results and long-term performance prediction of a domestic thermosiphon solar water heater in Algiers, Algeria

    Energy Technology Data Exchange (ETDEWEB)

    Zerrouki, A.; Said, N.; Tedjiza, B. [CDER, Route de l' Observatoire BP, Algiers (Algeria); Boumedien, A. [USTHB, Algiers (Algeria). Institut de Genie-Mecanique

    2002-01-01

    Experimental tests have been conducted following the recommended CSTG guidelines in outdoor conditions, in order to evaluate a thermosiphon Solar Domestic Hot Water (SDHW) system. This thermosiphonic solar system tested represents a good sample of various characteristics for SDHW systems manufactured by the Algerian industry. Heating of water utilising solar energy is a well-known and established technology in many parts of Algeria. With increasing number of solar heating systems on the market, a need was felt to adopt a standard testing and rating procedure for them. The introduction of test procedures should provide an equitable basis for competition amongst manufacturers and an essential criterion for design and selection of the equipment. (author)

  7. Solar Ray Tracing Analysis to Determine Energy Availability in a CPC Designed for Use as a Residential Water Heater

    Directory of Open Access Journals (Sweden)

    Miguel Terrón-Hernández

    2018-01-01

    Full Text Available Compound parabolic concentrators are relevant systems used in solar thermal technology. With adequate tailoring, they can be used as an efficient and low-cost alternative in residential water heating applications. This work presents a simulation study using a ray tracing analysis. With this technique, we simulate the interaction between solar rays and solar concentrator to quantify the amount of energy that impinges on the receiver at a particular time. Energy availability is evaluated in a comparison of two configurations throughout the year: static setup at 21° and multi-position setup; tilted with respect to the horizontal, depending on three seasonal positions: 0° for summer, 16° for spring/autumn, and 32° for winter, with the aim to evaluate the amount of available energy in each season. The fact that a tracking system can be dispensed with also represents an economical option for the proposed application. The results showed that at 21°, the proposed solar Compound Parabolic Concentrator (CPC works satisfactorily; however, by carrying out the selected angular adjustments, the overall energy availability increased by 22%, resulting in a more efficient option. The most effective design was also built and analyzed outdoors. The obtained thermal efficiency was of ~43%. The optical design and its evaluation developed herein proved to be a valuable tool for prototype design and performance evaluation.

  8. Comparative studies on chemical, hot and cold water treatments of ...

    African Journals Online (AJOL)

    Chemical, bot and cold-water treatments were evaluated for effectiveness in cleaning banana suckers of weevils. Preliminarily, the effectiveness of paring suckers on removal of weevils and nematodes from banana suckers was validated. Results indicated a 36.6%, 67.9% and 96.3% reduction of larvae in corms treated with ...

  9. Solar Heating of Buildings and Domestic Hot Water. Revision.

    Science.gov (United States)

    1980-05-01

    double (80%-100%) the selling price. 120 3. 10 Additional Costs - Worksheet G Worksheet G is a convenient checklist to collect costs associated with...Washington, D .C., Oct 1975. Energy Research and Development Administration (1976). An economic analysis of solar water and space heating. DSE -2322-1

  10. NORTH PORTAL-HOT WATER CALCULATION-SHOP BUILDING #5006

    Energy Technology Data Exchange (ETDEWEB)

    R. Blackstone

    2006-01-25

    The purpose of this design analysis and calculation is to determine the demand for domestic cold water and to size the supply main for the Shop Building No.5006 in accordance with the Uniform Plumbing Code (UPC) (Section 4.4.1) and the U.S. Department of Energy, Order 6430.1A-1540 (Section 4.4.2).

  11. Design tool for large solar hot water systems - Uniform optimization of components and economy

    NARCIS (Netherlands)

    Visser, H.

    1996-01-01

    In close collaboration with the parties concerned, i.e. both the sellers and investors, a design and optimization method for large solar hot water systems is being developed. In order to support investors in achieving the feasibility of such systems, the normalized method including software tool for

  12. Economic Model Predictive Control for Hot Water Based Heating Systems in Smart Buildings

    DEFF Research Database (Denmark)

    Awadelrahman, M. A. Ahmed; Zong, Yi; Li, Hongwei

    2017-01-01

    This paper presents a study to optimize the heating energy costs in a residential building with varying electricity price signals based on an Economic Model Predictive Controller (EMPC). The investigated heating system consists of an air source heat pump (ASHP) incorporated with a hot water tank...

  13. Achieving low return temperature for domestic hot water preparation by ultra-low-temperature district heating

    DEFF Research Database (Denmark)

    Yang, Xiaochen; Svendsen, Svend

    2017-01-01

    to achieve high efficiency of the ULTDH system, the return temperature should be as low as possible. For the energy-efficient buildings in the future, it is feasible to use ULTDH to cover the space heating demand. However, considering the comfort and hygiene requirements of domestic hot water (DHW...

  14. MICROBIAL POPULATION OF HOT SPRING WATERS IN ESKİŞEHİR/TURKEY

    Directory of Open Access Journals (Sweden)

    Nalan YILMAZ SARIÖZLÜ

    2012-02-01

    Full Text Available In order to investigate and find out the bacterial community of hot spring waters in Eskişehir, Turkey, 7 hot spring water samples were collected from 7 different hot springs. All samples were inoculated using four different media (nutrient agar, water yeast extract agar, trypticase soy agar, starch casein agar. After incubation at 50 ºC for 14 days, all bacterial colonies were counted and purified. Gram reaction, catalase and oxidase properties of all isolates were determined and investigated by BIOLOG, VITEK and automated ribotyping system (RiboPrinter. The resistance of these bacteriawas examined against ampiciline, gentamisine, trimethoprime-sulphamethoxazole and tetracycline. As a result, heat resistant pathogenic microorganisms in addition to human normal flora were determined in hot spring waters (43-50 ºC in investigated area. Ten different species belong to 6 genera were identified as Alysiella filiformis, Bordetella bronchiseptica, B. pertussis, Molexalla caprae, M. caviae, M. cuniculi, M. phenylpyruvica, Roseomonas fauriae, Delftia acidovorans and Pseudomonas taetrolens.

  15. Controlling Aphelenchoides subtenuis nematodes with a hot water treatment in Crocus and Allium

    NARCIS (Netherlands)

    Leeuwen, van P.J.; Trompert, J.P.T.

    2011-01-01

    Several bulbous crops like Crocus, Allium and some species of Tulipa and Narcissus can be infected with the nematode Aphelenchoides subtenuis. The nematodes cause retarded growth, poor or no flowering and eventually death of the bulbs and corms. A hot water treatment after lifting the bulbs has

  16. Ecofriendly hot water treatment reduces postharvest decay and elicits defense response in kiwifruit

    Science.gov (United States)

    Hot water treatment (HWT) of fruit is an effective approach for managing postharvest decay of fruits and vegetables. In the present study, the effects of HWT (45 degrees C for 10 min) on the growth of Botrytis cinerea and Penicillium expansum in vitro, and gray (B. cinerea) and blue mold (P. expans...

  17. Mango fruit aroma volatile production following quarantine hot water treatment and subsequent ripening

    Science.gov (United States)

    Mangos are an important tropical fruit crop worldwide that are appreciated for their attractive peel and flesh colors, juicy texture, sweetness, and unique aroma. Mangos exported to the U.S. receive quarantine hot water treatment (QHWT) at 46.1 °C for 65 to 110 min (depending on fruit shape and size...

  18. Numerical calculation and optimal design of a hot water circulation pump

    Science.gov (United States)

    Zhang, H.; Y Kong, F.; Xia, B.; Tan, L. W.

    2013-12-01

    The problem of hot water circulation pump head shortage is common. In this paper, numerical simulation technology, combined with orthogonal experimental design, was used to research optimal designs to improve the hot water circulation pump's head. CFX software was used to calculate the flow field in the pump, and the head-flow rate curve could be achieved. The accuracy of CFD was validated through comparison between numerical and experimental data. According to the experience, the number of impeller blades, thickness and width of impeller outlet were changed to improve the hot water circulation pump's head. A three factors and level values of model pump orthogonal experiment was designed, and numerical simulation of whole flow field based on CFX was adopted to implement the orthogonal experiment. Finally, the best designed scheme for model pump was obtained. The analysis of results indicates that the head of hot water circulation pump has increased by 7.77% at rated conditions. The distribution in impellers' internal flow field is symmetrical, and accords with the law of fluids flow in the common centrifugal pump.

  19. Controlling tulip stem nematodes in tulip bulbs by a hot water treatment

    NARCIS (Netherlands)

    Dam, van M.F.N.

    2013-01-01

    A hot water treatment (HWT) protocol is needed to control tulip stem nematode (TSN) in tulip bulbs. A HWT above approximately 45°C in tulips is assumed to be harmful to the bulbs. Experience with HWT to destroy stem nematodes in daffodils shows that the required temperature for this is 4 hours at

  20. Antiinflammatory Activity of Hot Water Infusion of Nyctanthes arbo-tristis Flowers.

    Science.gov (United States)

    Ratnasooriya, W D; Jayakody, J R A C; Handunnetti, S M; Ratnasooriya, C D T; Weerasekera, K R

    2015-01-01

    In Sri Lankan ethnomedicate it is claimed the flowers of Nyctanthes arbo-tristis is effective in the treatment of inflammatory conditions but this has not been scientifically validated. This experiment was carried to investigate the antinflammatory potential of hot water infusion of Nyctanthes arbo-tristis flowers. Oral antiinflammatory activity of hot water infusion of Nyctanthes arbo-tristis flowers (concentrations: 3.75, 7.5, 12.5 and 18.75 mg/kg) was assessed in rats using both acute (carrageenan-induced paw oedema assay) and chronic (formaldehyde induced-paw oedema and cotton pellet-granuloma tests) inflammatory models. In an attempt to investigate its mode of action, antihistamine activity (by wheal test), inhibition of prostaglandin synthesis (by enteropooling test), inhibition of Tumor necrosis factorα secretion (using human mononuclear cells), and suppression of vascular permeability (acetic acid-induced vascular permeability test) and cytotoxicity (Evans blue test) were assessed. In the carrageenan-induced paw oedema test, hot water infusion simultaneously suppressed both initial and late stages of inflammation in an inversely dose related manner. Hot water infusion also inhibited paw oedema in formalin and cotton pellet granuloma tests. In addition, this infusion exhibited marked anti histamine activity, prostaglandin synthesis inhibition and suppression of vascular permeability. These findings scientifically support the traditional use of Nyctanthes arbo-tristis flowers in treatment of inflammatory conditions.

  1. Sulfuric acid and hot water treatments enhance ex vitro and in vitro ...

    African Journals Online (AJOL)

    PRECIOUS

    2009-11-16

    Nov 16, 2009 ... Seeds of Hibiscus dasycalyx S. F. Blake and Shiller, a federally listed candidate endangered species and native to North America and two variants of Hibiscus acetosella Welw. ex. Hiern were scarified using sulfuric acid and hot water. The effects of the scarification methods on in vitro and ex vitro.

  2. Sulfuric acid and hot water treatments enhance ex vitro and in vitro ...

    African Journals Online (AJOL)

    Seeds of Hibiscus dasycalyx S. F. Blake and Shiller, a federally listed candidate endangered species and native to North America and two variants of Hibiscus acetosella Welw. ex. Hiern were scarified using sulfuric acid and hot water. The effects of the scarification methods on in vitro and ex vitro germination in both ...

  3. Effects of hot water extraction pretreatment on pyrolysis of shrub willow

    Science.gov (United States)

    Treatment of biomass via hot water extraction (HWE) reduces the amount of hemicellulose and ash in the biomass resulting in a concentration of cellulose and lignin content. In this study, we tested the effect of HWE as a biomass pretreatment on the pyrolysis of shrub willow via both conventional he...

  4. Effects of hot-water extraction on the thermochemical conversion of shrub willow via fast pyrolysis

    Science.gov (United States)

    Hot-water extraction (TM) (HWE) is a pretreatment technology designed to facilitate the subsequent hydrolysis of cellulose by removing the majority of the hemicellulose and ash content from the solid biomass. The HWE process generates salable sugars and other products as part of the process. The bio...

  5. Effects of Hot and Cold Water Pre-Treatments on Emergence of ...

    African Journals Online (AJOL)

    An experiment was carried out to check the effect of two pre germination treatments on the emergence of seeds of acacia senegal at the Department of Forestry and Wildlife, University of Maiduguri nursery. The treatments used were immersion of the seeds in cold water (at room temperature) for 8, 12 and 24 hours and hot ...

  6. Efficacy of brown sugar flotation and hot water methods for detecting Rhagoletis indifferens (Dipt., Tephritidae) larvae

    Science.gov (United States)

    The brown sugar flotation and hot water methods are accepted procedures for detecting larval western cherry fruit fly, Rhagoletis indifferens Curran, in sweet cherry [Prunus avium (L.) L.] and could be included in a systems approach for showing the absence of larvae in fruit. The methods require cr...

  7. Stress corrosion cracking mechanisms of Fe-based alloys in hydrogenated hot water

    Energy Technology Data Exchange (ETDEWEB)

    Coull, Z. [Univ. of Toronto, Dept. of Chemical Engineering and Applied Chemistry, Toronto, Ontario (Canada)]. E-mail: zcoull@chem-eng.utoronto.ca

    2006-07-01

    It is generally accepted that carbon steel resists Stress Corrosion Cracking (SCC) in hot water provided the oxygen content is low enough; however, isolated cracking events have occurred, apparently in fully reducing conditions, and these may or may not be true SCC. There are also occasional reports of SCC of austenitic stainless steel in reducing conditions where cold work may play a critical role. SCC though originally seen in sensitized material at oxidizing potentials persists to low potentials and in cold-worked but unsensitized material. We suspect from the literature that alloying with Ni introduces a susceptibility to SCC in reducing hot water as well as in caustic solution. Our hypothesis is that Ni causes SCC, and Cr retards it; so stainless steel has just enough Cr to protect against SCC under most conditions. We are examining this using model Fe-based materials and environments designed to separate the effects of different parameters. Early results suggest that Fe-Ni alloys and austenitic SS both undergo de-alloying and SCC in reducing caustic solutions. It is hypothesised that if these alloys are indeed susceptible to dealloying (and hence to SCC) in this environment then we can reasonably project that their behaviour in reducing, hot pure water may be similar. This is pertinent to understanding recent failures in high temperature, high pressure aqueous systems. As a first step we have investigated the surface reactions that occur in caustic solutions and in hot water. (author)

  8. Prototype solar heated hot water systems and double-walled heat exchangers. Progress report

    Energy Technology Data Exchange (ETDEWEB)

    1978-10-01

    A collection of quarterly and monthly reports from Elcam, Inc., covering progress made from January 1, 1978, through September 30, 1978, is presented. Elcam, is developing two solar-heated hot water prototype systems and two heat exchangers. This effort consists of development, manufacture, installation, maintenance, problem resolution, and system evaluation.

  9. Non-parametric method for separating domestic hot water heating spikes and space heating

    DEFF Research Database (Denmark)

    Bacher, Peder; de Saint-Aubain, Philip Anton; Christiansen, Lasse Engbo

    2016-01-01

    In this paper a method for separating spikes from a noisy data series, where the data change and evolve over time, is presented. The method is applied on measurements of the total heat load for a single family house. It relies on the fact that the domestic hot water heating is a process generatin...

  10. Commercial Integrated Heat Pump with Thermal Storage --Demonstrate Greater than 50% Average Annual Energy Savings, Compared with Baseline Heat Pump and Water Heater (Go/No-Go) FY16 4th Quarter Milestone Report

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Bo [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Baxter, Van D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Rice, C. Keith [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Abu-Heiba, Ahmad [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-03-01

    For this study, we authored a new air source integrated heat pump (AS-IHP) model in EnergyPlus, and conducted building energy simulations to demonstrate greater than 50% average energy savings, in comparison to a baseline heat pump with electric water heater, over 10 US cities, based on the EnergyPlus quick-service restaurant template building. We also assessed water heating energy saving potentials using ASIHP versus gas heating, and pointed out climate zones where AS-IHPs are promising.

  11. Solar heating and hot water system installed at Saint Louis, Missouri

    Science.gov (United States)

    1980-01-01

    The solar heating and hot water system installed at the William Tao & Associates, Inc., office building in St. Louis, Missouri is described, including maintenance and construction problems, final drawings, system requirements, and manufacturer's component data. The solar system was designed to provide 50 percent of the hot water requirements and 45 percent of the space heating needs for a 900 sq ft office space and drafting room. The solar facility has 252 sq ft of glass tube concentrator collectors and a 1000 gallon steel storage tank buried below a concrete slab floor. Freeze protection is provided by a propylene glycol/water mixture in the collector loop. The collectors are roof mounted on a variable tilt array which is adjusted seasonally and is connected to the solar thermal storage tank by a tube-in-shell heat exchanger. Incoming city water is preheated through the solar energy thermal storage tank.

  12. Solar heating and hot water system installed at Saint Louis, Missouri

    Science.gov (United States)

    1980-04-01

    The solar heating and hot water system installed at the William Tao & Associates, Inc., office building in St. Louis, Missouri is described, including maintenance and construction problems, final drawings, system requirements, and manufacturer's component data. The solar system was designed to provide 50 percent of the hot water requirements and 45 percent of the space heating needs for a 900 sq ft office space and drafting room. The solar facility has 252 sq ft of glass tube concentrator collectors and a 1000 gallon steel storage tank buried below a concrete slab floor. Freeze protection is provided by a propylene glycol/water mixture in the collector loop. The collectors are roof mounted on a variable tilt array which is adjusted seasonally and is connected to the solar thermal storage tank by a tube-in-shell heat exchanger. Incoming city water is preheated through the solar energy thermal storage tank.

  13. Solar heating and hot water system installed at St. Louis, Missouri. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1980-04-01

    Information is provided on the solar heating and hot water system installed at the William Tao and Associates, Inc., office building in St. Louis, Missouri. The information consists of description, photos, maintenance and construction problems, final drawing, system requirements and manufacturer's component data. The solar system was designed to provide 50% of the hot water requirements and 45% of the space heating needs for a 900 square foot office space and drafting room. The solar facility has 252 square foot of glass tube concentrator collectors and a 1000 gallon steel storage tank buried below a concrete slab floor. Freeze protection is provided by a propylene glycol/water mixture in the collector loop. The collectors are roof mounted on a variable tilt array which is adjusted seasonally and is connected to the solar thermal storage tank by a tube-in-shell heat exchanger. Incoming city water is preheated through the solar energy thermal storage tank.

  14. Solar hot water space heating system. Technical progress report

    Energy Technology Data Exchange (ETDEWEB)

    Van Dam, T

    1979-08-13

    A retrofit solar heating system was installed on Madison Hall at Jordan College, Cedar Springs, Michigan. The system provides heating and domestic water preheating for a campus dormitory. Freeze protection is provided by a draindown system. The building and solar system, construction progress, and design changes are described. Included in appendices are: condensate trap design, structural analysis, pictures of installation, operating instructions, maintenance instructions, and as-built drawings. (MHR)

  15. Changes in antioxidant and fruit quality in hot water-treated ‘Hom Thong’ banana fruit during storage

    Science.gov (United States)

    The effects of hot water treatment on antioxidant phytochemicals and fruit quality were investigated in banana fruit of cv. Gros Michel (Musa acuminata, AAA Group, locally called cv. Hom Thong) by immersing fruits in hot water (50 'C) for 10 min, before storage at 25 'C for 10 days or 14 'C for 8 da...

  16. Investigation af a solar heating system for space heating and domestic hot water supply with a high degree of coverage

    DEFF Research Database (Denmark)

    Vejen, Niels Kristian

    1999-01-01

    A solar storage tank for space heating and domestic hot water supply was designed and testet in af laboratory test facility.......A solar storage tank for space heating and domestic hot water supply was designed and testet in af laboratory test facility....

  17. A continuum from clear to cloudy hot-Jupiter exoplanets without primordial water depletion

    OpenAIRE

    Sing, DK; Fortney, JJ; Nikolov, N.; Wakeford, HR; Kataria, T.; Evans, TM; Aigrain, S; Ballester, GE; Burrows, AS; Deming, D.; Désert, JM; Gibson, NP; Henry, GW; Huitson, CM; Knutson, HA

    2016-01-01

    © 2016 Macmillan Publishers Limited. All rights reserved. Thousands of transiting exoplanets have been discovered, but spectral analysis of their atmospheres has so far been dominated by a small number of exoplanets and data spanning relatively narrow wavelength ranges (such as 1.1-1.7 micrometres). Recent studies show that some hot-Jupiter exoplanets have much weaker water absorption features in their near-infrared spectra than predicted. The low amplitude of water signatures could be explai...

  18. Special wettable nanostructured copper mesh achieved by a facile hot water treatment process

    Science.gov (United States)

    Saadi, Nawzat S.; Hassan, Laylan B.; Brozak, Matt; Karabacak, Tansel

    2017-09-01

    In this research, a special wettable copper mesh with superhydrophobicity and superoleophilicity properties is reported using a low-cost, eco-friendly, rapid, and scalable synthesis method. Hot water treatment (HWT) method is used to integrate the micro-textured copper mesh surface with a nanoscale roughness to achieve a hierarchical micro-nano structured surface. The surface energy of the nanoscale roughened copper mesh reduced by coating the hot water treated mesh with polymer ligands containing thiol or fluorine functional groups of low energy. Surface morphology characterization showed the formation of copper oxide nanostructures on the mesh surface by hot water process performed at 95 °C and under a low dissolved oxygen condition. X-ray diffraction patterns reveal the development of stable, uniformly distributed, and compactly arranged, cubic and plate-like nanostructures of cuprous oxide (Cu2O) on the copper mesh surface. The surface wettability of the as-prepared copper mesh was assessed by contact angle (CA) measurement for water and several oils and organic solvents. CA values showed the formation of special wettable copper mesh surface with superhydrophobic property with water contact angle of about 157° and superoleophilic property with oil contact angle as low as 0°. In addition, the effect of the mesh’s geometry on the wetting property was examined through correlations between wire diameter, pore size, and optimal values for the highest water CA.

  19. Decomposition behavior of hemicellulose and lignin in the step-change flow rate liquid hot water.

    Science.gov (United States)

    Zhuang, Xinshu; Yu, Qiang; Wang, Wen; Qi, Wei; Wang, Qiong; Tan, Xuesong; Yuan, Zhenhong

    2012-09-01

    Hemicellulose and lignin are the main factors limiting accessibility of hydrolytic enzymes besides the crystallinity of cellulose. The decomposition behavior of hemicellulose and lignin in the step-change flow rate hot water system was investigated. Xylan removal increased from 64.53% for batch system (solid concentration 4.25% w/v, 18 min, 184°C) to 83.78% at high flow rates of 30 ml/min for 8 min, and then 10 ml/min for 10 min. Most of them (80-90%) were recovered as oligosaccharide. It was hypothesized that the flowing water could enhance the mass transfer to improve the sugars recovery. In addition, the solubilization mechanism of lignin in the liquid hot water was proposed according to the results of Fourier transform-infrared spectroscopy and scanning electron microscopy of the water-insoluble fraction and gas chromatography-mass spectrometry of the water-soluble fraction. It was proposed that lignin in the liquid hot water first migrated out of the cell wall in the form of molten bodies, and then flushed out of the reactor. A small quantity of them was further degraded into monomeric products such as vanillin, syringe aldehyde, coniferyl aldehyde, ferulic acid, and p-hydroxy-cinnamic acid. All of these observations would provide important information for the downstream processing, such as purification and concentration of sugars and the enzymatic digestion of residual solid.

  20. Domestic hot water. Measurements of consumption and heat loss from circulation pipes; Varmt brugsvand. Maaling af forbrug og varmetab fra cirkulationsledninger

    Energy Technology Data Exchange (ETDEWEB)

    Boehm, B.; Schroeder, F.; Bergsoee, N.C.

    2009-07-01

    circulation line or use of HWAT should be carefully analysed. 3) For office buildings it is recommended to consider the use of a decentralized, electrical hot water production in preference to a traditional solution with circulation lines. Even if the electricity consumption is weighted by a factor of 2.5 it may be advantageous to use decentralized, electrical water heaters. 4) For apartment buildings, the trend is that it should be possible to measure the consumption in each individual apartment. Therefore, flat stations with a district heating unit in each apartment should be compared with traditional ways of supplying and measuring heat to apartments (heat allocators). 5) New types of circulation lines should be considered, e.g. concentric pipes or twin pipes, which may reduce pipe heat losses considerably. Also, prefabricated vertical pipes should be considered. Regulations as regards inaccessible joints and penetrations including requirements regarding precautionary measures concerning fire must be observed. 6) It is recommended that in depth analyses are conducted on how much of the heat loss from the DHW system that actually can be utilised in a building. (LN)

  1. Influence of hot water dip on fruit quality, phenolic compounds and antioxidant capacity of Satsuma mandarin during storage.

    Science.gov (United States)

    Shen, Yan; Zhong, Liezhou; Sun, Yujing; Chen, Jianchu; Liu, Donghong; Ye, Xingqian

    2013-12-01

    The influence of hot water dips (50, 52 and 54  for 3 min) on fruit quality, phenolic compounds and antioxidant capacity of Satsuma mandarin during 60 days' storage at 10  was investigated. Hot water dips did not affect fruit quality attributes as well as ascorbic acid content, and 50  treatment significantly reduced fruit weight loss. Significant increases of flavonoids were found in all hot water treated fruit from after treatments till 15 days of storage, whereas phenolic acids were not greatly affected. Hot water dipping at 50  significantly increased total phenolics and antioxidant capacity of Satsuma mandarin immediately after treatment and maintained similar levels with control during storage, while 52 and 54  treatments showed relatively lower levels. The results suggested that hot water dipping at 50  for 3 min can be a promising way to retain functional quality of storing Satsuma mandarin.

  2. The impact of the hot tap water load pattern in the industrial hall on the energy yield from solar collectors

    Science.gov (United States)

    Fidorów-Kaprawyl, Natalia; Dudkiewicz, Edyta

    2017-11-01

    The systems using solar energy, popular in Poland, can be used to supply hot water for the installation used by employees of industrial halls. In manufacturing plants, employing a large number of people, the demand for hot water is practically constant throughout the year and is characterized by periodic use at the end of each work shift. Dynamics of the hot water consumption depends on the number of shifts as well as working days and holidays. Additionally the maximum hot tap water demand occurs in the whole period of installation operation. In polish climatic conditions the solar collectors' systems have the largest capacity in the summer, while in winter they need to be assisted. Beside that the supply of renewable energy is uneven and depends on weather conditions. In the paper the one-hour step analysis concerning the dependence of the load pattern of the hot tap water preparation system on the energy yield from solar collectors had been performed.

  3. Pressurizer Heater and Safety Valve Test for SPACE code

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Dong Hyuk; Youn, Bum Soo; Jun, Hwang Yong; Kim, Se Yun; Ha, Sang Jun [KEPCO Research Institute, Daejeon (Korea, Republic of)

    2011-05-15

    The Korea nuclear industry has been developing a thermal-hydraulic analysis code for safety analysis of PWR(pressurized water reactor). The new code is named SPACE(Safety and Performance Analysis Code for Nuclear Power Plant). In this paper, the pressurizer heater model and safety valve for SPACE code is tested. The SPACE code input for pressurizer is developed and simulations are performed. Calculations were performed with and without heater and safety valve model and results are compared to confirm effectiveness of heater and safety valve

  4. Conceptual design of a helium heater for high temperature applications

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Xue Zhou, E-mail: jin@kit.edu; Chen, Yuming; Ghidersa, Bradut-Eugen

    2014-10-15

    Highlights: •A special design of heater with two vessels is introduced for the operation at 10 MPa and 800 °C. •The additional coupling between the cold leg and the hot leg of the loop due to the heater design has an impact on the loop energy budget. •Reducing the heat transfer between the two flow channels inside the heater by means of a helium gap in the inlet nozzle is proven to be effective. -- Abstract: The Karlsruhe Advanced Technologies Helium Loop (KATHELO) has been designed for testing divertor modules as well as qualifying materials for high heat flux, high temperature (up to 800 °C) and high pressure (10 MPa) applications. The test section inlet temperature level is controlled using a process electrical heater. To cope with the extreme operating conditions, a special design of this unit has been proposed. In this paper the conceptual design of the unit will be presented and the impact of the coupling between the cold and hot helium gas on the overall efficiency of the loop will be investigated. The detailed thermal-hydraulic analysis of the feed through of the hot helium into the low temperature pressure vessel using ANSYS CFX will be presented. The impact of the design choices on the overall energy budget of the loop will be analyzed using RELAP5-3D.

  5. Promising freeze protection alternatives in solar domestic hot water systems

    Energy Technology Data Exchange (ETDEWEB)

    Bradley, David E. [Univ. of Wisconsin, Madison, WI (United States)

    1997-01-01

    Since the gains associated with solar thermal energy technologies are comparatively small in relation to the required capital investment, it is vital to maximize conversion efficiency. While providing the necessary function of freeze protection, the heat exchanger commonly included in solar domestic water heating systems represents a system inefficiency. This thesis explores two alternate methods of providing freeze protection without resorting to a heat exchanger. Commonly, collectors are made of rigid copper tubes separated by copper or aluminum fins. Cracking damage can occur when water is allowed to freeze and expand inside the non compliant tubes. The possibility of making collectors out of an elastic material was investigated and shown to be effective. Since unlike copper, elastomers typically have low thermal conductivities, the standard collector performance prediction equations do not apply. Modified thermal performance prediction equations were developed which can be used for both low and high thermal conductivity materials to provide accurate predictions within a limited range of plate geometries. An elastomeric collector plate was then designed and shown to have comparable performance to a copper plate collector whose aperture area is approximately 33% smaller. Another options for providing freeze protection to an SDHW system is to turn it off during the winter. Choosing a three-season operating period means two things. First, the system will have different optimums such as slope and collector area. Second, the wintertime solar energy incident on the collector is unavailable for meeting a heating load. However, the system`s heat exchanger becomes unnecessary and removing it increases the amount of energy that arrives at the storage tank during those periods in which the system is operating.

  6. Solar process water heat for the IRIS images custom color photo lab

    Science.gov (United States)

    1980-01-01

    The solar facility located at a custom photo laboratory in Mill Valley, California is described. It was designed to provide 59 percent of the hot water requirements for developing photographic film and domestic hot water use. The design load is to provide 6 gallons of hot water per minute for 8 hours per working day at 100 F. It has 640 square feet of flat plate collectors and 360 gallons of hot water storage. The auxillary back up system is a conventional gas-fired water heater. Site and building description, subsystem description, as-built drawings, cost breakdown and analysis, performance analysis, lessons learned, and the operation and maintenance manual are presented.

  7. Chemical and biological properties of hot water extract from delipidated cells of Mycobacterium bovis strain BCG.

    Science.gov (United States)

    Sato, H; Yokosawa, A; Arai, H; Nagai, H; Kurita, K

    1976-09-01

    A water-soluble fraction was isolated from delipidated cells of Mycobacterium bovis strain BCG by extraction with hot water. Chemical analyses revealed that the above fraction presumably consisted of a peptidoglycan containing 5-10% of nucleic acids. When it was injected into guinea pigs with Freund's incomplete adjuvant plus egg white albumin as antigen, an increase of circulating antibody was observed as shown by the augmented titers of precipitin and hemagglutinin. The results of skin test and corneal reaction indicated that the fraction mentioned above induced delayed hypersensitivity to egg white albumin. Footpad reaction in mice demonstrated that the above fraction induced delayed hypersensitivity to sheep red blood cells. It was confirmed in addition that the adjuvant activity of this fraction was not due to the presence of nucleic acids. This adjuvant-active fraction was designated as HSA (hot-water soluble adjuvant.

  8. Evaluation of a new monochloramine generation system for controlling Legionella in building hot water systems.

    Science.gov (United States)

    Duda, Scott; Kandiah, Sheena; Stout, Janet E; Baron, Julianne L; Yassin, Mohamed; Fabrizio, Marie; Ferrelli, Juliet; Hariri, Rahman; Wagener, Marilyn M; Goepfert, John; Bond, James; Hannigan, Joseph; Rogers, Denzil

    2014-11-01

    To evaluate the efficacy of a new monochloramine generation system for control of Legionella in a hospital hot water distribution system. A 495-bed tertiary care hospital in Pittsburgh, Pennsylvania. The hospital has 12 floors covering approximately 78,000 m(2). The hospital hot water system was monitored for a total of 29 months, including a 5-month baseline sampling period prior to installation of the monochloramine system and 24 months of surveillance after system installation (postdisinfection period). Water samples were collected for microbiological analysis (Legionella species, Pseudomonas aeruginosa, Stenotrophomonas maltophilia, Acinetobacter species, nitrifying bacteria, heterotrophic plate count [HPC] bacteria, and nontuberculous mycobacteria). Chemical parameters monitored during the investigation included monochloramine, chlorine (free and total), nitrate, nitrite, total ammonia, copper, silver, lead, and pH. A significant reduction in Legionella distal site positivity was observed between the pre- and postdisinfection periods, with positivity decreasing from an average of 53% (baseline) to an average of 9% after monochloramine application (Pevaluation in the United States of a commercially available monochloramine system installed on a hospital hot water system for Legionella disinfection, and it demonstrated a significant reduction in Legionella colonization. Significant increases in microbial populations or other negative effects previously associated with monochloramine use in large municipal cold water systems were not observed.

  9. The main chemical properties of hot and cold mineral waters in Bayankhongor, Mongolia

    Directory of Open Access Journals (Sweden)

    D Oyuntsetseg

    2014-12-01

    Full Text Available In the current study, hot and cold mineral springs and sub mineral waters in the Bayankhongor province were examined for their chemical characteristics and identified cold mineral waters classification according to mineral water classification of Mongolia. The hot spring waters belong to Na+-HCO3- and Na+-SO42- types. The cold mineral spring of Lkham belongs to Ca2+-HCO3- type. All sub mineral waters are generally located in the two areas (northern part or mountain forest area and the southern part or Gobi desert area. TDS concentrations of cold springs of the southern part in the study area were higher than northern part’s cold springs. The total dissolved silica content of cold spring was ranged from 4.5mg/L to 26 mg/L which did not correspond to requirements of mineral water standard of Mongolia. Thus, these cold springs are belonging to sub mineral water classification. The sub mineral waters were characterized into four types such as a Ca2+-SO42-, Na+-SO42-, Na+-HCO3 and Ca2+ - HCO3 by their chemical composition in the study area. The values for the quartz, chalcedony geothermometer and the Na/K geothermometer were quite different. The silica-enthalpy mixing model predicts a subsurface reservoir temperature between 124 and 197°C and most of the hot waters have been  probably mixed with cold water. The result shows that an averaged value of calculated temperature ranges from 77°C to 119°C which indicates that studied area has low temperature geothermal resources. DOI: http://doi.dx.org/10.5564/mjc.v15i0.324 Mongolian Journal of Chemistry 15 (41, 2014, p56-62

  10. Low Cost Solar Water Heater

    Energy Technology Data Exchange (ETDEWEB)

    William Bostic

    2005-12-16

    This project was directed by NREL to pursue development of an all polymer solar thermal collector. The proposed design utilized a dual sheet thermoform process to coincidentally form the absorber as well as the containment structure to support the glazing. It utilized ventilation to overcome stagnation degradation of the polymer materials.

  11. The Development of a Roof Integrated Solar Hot Water System

    Energy Technology Data Exchange (ETDEWEB)

    Menicucci, David F. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Energy Infrastructure and DER Dept.; Moss, Timothy A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Solar Technologies Dept.; Palomino, G. Ernest [Salt River Project (SRP), Tempe, AZ (United States)

    2006-09-01

    The Salt River Project (SRP), in conjunction with Sandia National Laboratories (SNL) and Energy Laboratories, Inc. (ELI), collaborated to develop, test, and evaluate an advanced solar water-heating product for new homes. SRP and SNL collaborated under a Department of Energy Cooperative Research and Development Agreement (CRADA), with ELI as SRP's industry partner. The project has resulted in the design and development of the Roof Integrated Thermal Siphon (RITH) system, an innovative product that features complete roof integration, a storage tank in the back of the collector and below the roofline, easy installation by homebuilders, and a low installed cost. SRP's market research guided the design, and the laboratory tests conducted at SNL provided information used to refine the design of field test units and indicated that the RITH concept is viable. ELI provided design and construction expertise and is currently configured to manufacture the units. This final report for the project provides all of the pertinent and available materials connected to the project including market research studies, the design features and development of the system, and the testing and evaluation conducted at SNL and at a model home test site in Phoenix, Arizona.

  12. Subsurface heaters with low sulfidation rates

    Energy Technology Data Exchange (ETDEWEB)

    John, Randy Carl; Vinegar, Harold J

    2013-12-10

    A system for heating a hydrocarbon containing formation includes a heater having an elongated ferromagnetic metal heater section. The heater is located in an opening in a formation. The heater section is configured to heat the hydrocarbon containing formation. The exposed ferromagnetic metal has a sulfidation rate that goes down with increasing temperature of the heater, when the heater is in a selected temperature range.

  13. Measure Guideline. Combination Forced-Air Space and Tankless Domestic Hot Water Heating Systems

    Energy Technology Data Exchange (ETDEWEB)

    Rudd, Armin [Building Science Corporation Industry Team (BSC), Somerville, MA (United States)

    2012-08-01

    This document describes design and application guidance for combination space and tankless domestic hot water heating systems (combination systems) used in residential buildings, based on field evaluation, testing, and industry meetings conducted by Building Science Corporation. As residential building enclosure improvements continue to drive heating loads down, using the same water heating equipment for both space heating and domestic water heating becomes attractive from an initial cost and space-saving perspective. This topic is applicable to single- and multi-family residential buildings, both new and retrofitted.

  14. Solar hot water system installed at Day's Inn Motel, Dallas, Texas (Valley View)

    Science.gov (United States)

    1980-01-01

    The solar system was designed to provide 65 percent of the total domestic hot water (DHW) demand. A liquid (water) flat plate collector (1,000 square feet) system automatically drains into the 1,000 gallon steel storage tank when the solar pump is not running. Heat is transferred from the DHW tanks through a shell and tube heat exchanger. A circulating pump between the DHW tanks and heat exchanger enables solar heated water to help make up standby losses. All pumps are controlled by differential temperature controllers.

  15. Solar hot water system installed at Days Inn Motel, Dallas, Texas (Forrest Lane)

    Science.gov (United States)

    1980-01-01

    The solar system was designed to provide 65 percent of the total Domestic Hot Water (DHW) demand. The liquid flat plate (water) collector (1,000 square feet) system automatically drains into the 1,000 gallon steel storage tank located in the mechanical room when the pump is not running. Heat is transferred from the storage tank to DHW tanks through a tube and shell heat exchanger. A circulating pump between the DHW tanks and the heat exchanger enables solar heated water to help make DHW tank standby losses. All pumps are controlled by differential temperature.

  16. Measure Guideline: Combination Forced-Air Space and Tankless Domestic Hot Water Heating Systems

    Energy Technology Data Exchange (ETDEWEB)

    Rudd, A.

    2012-08-01

    This document describes design and application guidance for combination space and tankless domestic hot water heating systems (combination systems) used in residential buildings, based on field evaluation, testing, and industry meetings conducted by Building Science Corporation. As residential building enclosure improvements continue to drive heating loads down, using the same water heating equipment for both space heating and domestic water heating becomes attractive from an initial cost and space-saving perspective. This topic is applicable to single- and multi-family residential buildings, both new and retrofitted.

  17. A Fluorine-free Slippery Surface with Hot Water Repellency and Improved Stability against Boiling.

    Science.gov (United States)

    Togasawa, Ryo; Tenjimbayashi, Mizuki; Matsubayashi, Takeshi; Moriya, Takeo; Manabe, Kengo; Shiratori, Seimei

    2018-01-31

    Inspired by natural living things such as lotus leaves and pitcher plants, researchers have developed many excellent antifouling coatings. In particular, hot-water-repellent surfaces have received much attention in recent years because of their wide range of applications. However, coatings with stability against boiling in hot water have not been achieved yet. Long-chain perfluorinated materials, which are often used for liquid-repellent coatings owing to their low surface energy, hinder the potential application of antifouling coatings in food containers. Herein, we design a fluorine-free slippery surface that immobilizes a biocompatible lubricant layer on a phenyl-group-modified smooth solid surface through OH-π interactions. The smooth base layer was fabricated by modification of phenyltriethoxysilane through a sol-gel method. The π-electrons of the phenyl groups interact with the carboxyl group of the oleic acid used as a lubricant, which facilitates immobilization on the base layer. Water droplets slid off the surface in the temperature range from 20 to 80 °C at very low sliding angles (boiling stability under hot water. We believe that this surface will be applied in fields in which the practical use of antifouling coatings is desirable, such as food containers, drink cans, and glassware.

  18. Heat treatment of wheat straw by immersion in hot water decreases mushroom yield in Pleurotus ostreatus.

    Science.gov (United States)

    Jaramillo Mejía, Santiago; Albertó, Edgardo

    2013-01-01

    The oyster mushroom, Pleurotus ostreatus, is cultivated worldwide. It is one of the most appreciated mushrooms due to its high nutritional value. Immersion of the substrate in hot water is one of the most popular and worldwide treatment used for mushroom farmers. It is cheap and easy to implement. To compare the yields obtained during mushroom production of P. ostreatus using different pre-treatments (immersion in hot water, sterilization by steam and the use of fungicide) to determine if they influence mushroom crop. Four different treatments of substrate (wheat straw) were carried out: (i) immersion in hot water (IHW); (ii) steam sterilization; (iii) chemical; and (iv) untreated. The residual water from the IHW treatment was used to evaluate the mycelium growth and the production of P. ostreatus. Carbendazim treatment produced highest yields (BE: 106.93%) while IHW produced the lowest BE with 75.83%. Sugars, N, P, K and Ca were found in residual water of IHW treatment. The residual water increased the mycelium growth but did not increase yields. We have proved that IHW treatment of substrate reduced yields at least 20% when compared with other straw treatments such as steam, chemical or untreated wheat straw. Nutrients like sugars, proteins and minerals were found in the residual water extract which is the resultant water where the immersion treatment is carried out. The loss of these nutrients would be the cause of yield decrease. Alternative methods to the use of IHW as treatment of the substrate should be considered to reduce economical loss. Copyright © 2012 Revista Iberoamericana de Micología. Published by Elsevier Espana. All rights reserved.

  19. The analysis of the hot water consumption and energy performance before and after renovation in multi-apartment buildings

    Science.gov (United States)

    Tumanova, K.; Borodinecs, A.; Geikins, A.

    2017-10-01

    The article presents the results of hot water supply system analysis. Taking into account that the current consumption of hot water differs from normative values, real measured data of hot water consumption in multi-apartment buildings from year 2013 until year 2015 have been analyzed. Also, the thermal energy consumption for hot water preparation has been analyzed. Based on aggregated data and taking into account the fact that renovated systems of hot water supply in existing multi-apartment buildings have same pipelines’ diameters, it was analyzed how these systems are economically and energy efficient. For the study, residential buildings in Riga, which have different architectural and engineering solutions for hot water supply systems, were selected. The study was based on thermal energy consumption measurements, which were taken at the individual heating system’s manifolds. This study was done in order to develop database on hot water consumption in civil buildings and define difference in key performance criteria in unclassified buildings. Obtained results allows to reach European Regional Development Fund project “NEARLY ZERO ENERGY SOLUTIONS FOR UNCLASSIFIED BUILDINGS” Nr. 1.1.1.116A048 main targets.

  20. Review of Various Solutions for avoiding critical levels of Legionella Bacteria in Domestic Hot Water System

    DEFF Research Database (Denmark)

    Yang, Xiaochen; Li, Hongwei; Svendsen, Svend

    2013-01-01

    Low temperature district heating (DH) is designed as 55/25oC for supply/return temperature to fulfill the low energy demand of future buildings. However, to secure the safety of domestic hot water, the supply temperature has to be kept around 60oC to avoid the existence of legionella, which...... reproduces rapidly at the temperature around 25oC- 45 oC. After several outbreaks of pheumonia and fever caused by legionella bacteria, most countries require 60 oC in the network and 50-55 oC at the faucets with periodic flush by hot water above 60 oC as disinfection solution. That makes obstacles of low...... temperature DH implementation. Therefore, effective solution of legionella bacteria is in urgent demand. To select optimal disinfection treatments for certain cases which are quite different in dimension or purpose of use, various methods were reviewed, including shock hyperchlorination, super heating...

  1. Hydrothermal pretreatment of wood by mild steam explosion and hot water extraction.

    Science.gov (United States)

    Wojtasz-Mucha, Joanna; Hasani, Merima; Theliander, Hans

    2017-10-01

    The aim of this work was to compare the two most common hydrothermal pre-treatments for wood - mild steam explosion and hot water extraction - both with the prospect of enabling extraction of hemicelluloses and facilitating further processing. Although both involve autohydrolysis of the lignocellulosic tissue, they are performed under different conditions: the most prominent difference is the rapid, disintegrating, discharge employed in the steam explosion opening up the structure. In this comparative study, the emphasis was placed on local composition of the pre-treated wood chips (of industrially relevant size). The results show that short hot water extraction treatments lead to significant variations in the local composition within the wood chips, while steam explosion accomplishes a comparably more even removal of hemicelluloses due to the advective mass transport during the explosion step. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Hot water immersion as a treatment for stonefish sting: A case report.

    Science.gov (United States)

    Darlene, F Ongkili; Phee-Kheng, Cheah

    2013-01-01

    The North Borneo state of Sabah is known worldwide for its beautiful islands and dive sites. Local hospitals deal with a number of marine-related injuries, including marine fauna envenomation by Scorpaenidae and Synanceiidae families of fish. We report a case of a tourist who presented with excruciating pain on her right foot after stepping on a stonefish. Despite being given parenteral analgesia and regional anaesthesia, the pain persisted. Her pain improved after she soaked her foot in hot water for about 30 minutes. No further treatment was required. We reviewed the literature comparing this inexpensive mode of treatment with other conventional treatments. We also explored the possibility of using hot water immersion for treatment of envenomation by other types of marine animals.

  3. Heated Debates: Hot-Water Immersion or Ice Packs as First Aid for Cnidarian Envenomations?

    Directory of Open Access Journals (Sweden)

    Christie L. Wilcox

    2016-04-01

    Full Text Available Cnidarian envenomations are an important public health problem, responsible for more deaths than shark attacks annually. For this reason, optimization of first-aid care is essential. According to the published literature, cnidarian venoms and toxins are heat labile at temperatures safe for human application, which supports the use of hot-water immersion of the sting area(s. However, ice packs are often recommended and used by emergency personnel. After conducting a systematic review of the evidence for the use of heat or ice in the treatment of cnidarian envenomations, we conclude that the majority of studies to date support the use of hot-water immersion for pain relief and improved health outcomes.

  4. Solar hot water system installed at Quality Inn, Key West, Florida

    Science.gov (United States)

    1980-01-01

    The solar energy hot water system installed in the Quality Inn, Key West, Florida, which consists of four buildings is described. Three buildings are low-rise, two-story buildings containing 100 rooms. The fourth is a four-story building with 48 rooms. The solar system was designed to provide approximately 50 percent of the energy required for the domestic hot water system. The solar system consists of approximately 1400 square feet of flat plate collector, two 500 gallon storage tanks, a circulating pump, and a controller. Operation of the system was begun in April 1978, and has continued to date with only three minor interruptions for pump repair. In the first year of operation, it was determined that the use of the solar facility resulted in forty percent fuel savings.

  5. Experimental study of the ecological impact of hot water/high pressure cleaning on rocky shores

    Energy Technology Data Exchange (ETDEWEB)

    Menot, L.; Chasse, C.; Kerambrun, L. [CEDRE, Plouzane (France)

    1998-09-01

    The efficiency of high pressure/hot water washing for cleaning oiled rocky shores was determined. The study also highlighted the level of tolerance towards high pressure/hot water of different intertidal biota and proposed some operational recommendations for using this technique in regards with the biota sensitivity range. The study showed that pressure, higher than 170 g/m{sup 2} on the substratum, had the most detrimental effects on intertidal biota. Temperatures between 25 and 53 degrees C had only minor effects. The most sensitive taxa were the foliaceous lichens and the barnacles. Crustose lichens and algae were found to be tolerant to both pressure and temperature. Seaweeds protected the underneath epifauna. 12 refs., 1 tab., 4 figs.

  6. Hot water epilepsy: Phenotype and single photon emission computed tomography observations.

    Science.gov (United States)

    Patel, Mehul; Satishchandra, Parthasarathy; Aravinda, Hanumanthapura; Bharath, Rose D; Sinha, Sanjib

    2014-10-01

    We studied the anatomical correlates of reflex hot water epilepsy (HWE) using multimodality investigations viz. magnetic resonance imaging (MRI), electroencephalography (EEG), and single photon emission computed tomography (SPECT). Five men (mean age: 27.0 ΁ 5.8 years) with HWE were subjected to MRI of brain, video-EEG studies, and SPECT scan. These were correlated with phenotypic presentations. Seizures could be precipitated in three patients with pouring of hot water over the head and semiology of seizures was suggestive of temporal lobe epilepsy. Ictal SPECT showed hyperperfusion in: left medial temporal - one, left lateral temporal - one, and right parietal - one. Interictal SPECT was normal in all five patients and did not help in localization. MRI and interictal EEG was normal in all the patients. The clinical and SPECT studies suggested temporal lobe as the seizure onset zone in some of the patients with HWE.

  7. Hot water epilepsy: Phenotype and single photon emission computed tomography observations

    Directory of Open Access Journals (Sweden)

    Mehul Patel

    2014-01-01

    Full Text Available We studied the anatomical correlates of reflex hot water epilepsy (HWE using multimodality investigations viz. magnetic resonance imaging (MRI, electroencephalography (EEG, and single photon emission computed tomography (SPECT. Five men (mean age: 27.0 ΁ 5.8 years with HWE were subjected to MRI of brain, video-EEG studies, and SPECT scan. These were correlated with phenotypic presentations. Seizures could be precipitated in three patients with pouring of hot water over the head and semiology of seizures was suggestive of temporal lobe epilepsy. Ictal SPECT showed hyperperfusion in: left medial temporal - one, left lateral temporal - one, and right parietal - one. Interictal SPECT was normal in all five patients and did not help in localization. MRI and interictal EEG was normal in all the patients. The clinical and SPECT studies suggested temporal lobe as the seizure onset zone in some of the patients with HWE.

  8. Study on Thermal Performance Assessment of Solar Hot Water Systems in Malaysia

    Directory of Open Access Journals (Sweden)

    Sulaiman Shaharin Anwar

    2014-07-01

    Full Text Available Solar Hot Water Systems (SHWS are gaining popularity in Malaysia due to increasing cost of electricity and also awareness of environmental issues related to the use of fossil fuels. The introduction of solar hot water systems in Malaysia is an indication that it has potential market. However, there is a need for a proper methodology for rating the energy performance of these systems. The main objective of this study is to assess the thermal performance of several SHWS subject to four different locations in Malaysia using combined direct measurement and computer modelling using the TRNSYS simulation program. The results showed distinct differences in performance of the systems as a result of locations and manufacturers. The findings could be used further in developing an acceptable rating system for SHWS in Malaysia.

  9. Pediatric burns due to hot water from water dispenser: a neglected issue that should be highly concerned.

    Science.gov (United States)

    Ma, Bing; Xi, Hui-Jun; Wang, Jia-Lin; Yan, Ying; Tang, Hong-Tai; Zhu, Shi-Hui; Lü, Kai-Yang; Xia, Zhao-Fan

    2012-06-01

    More and more Chinese drink hot water from water dispensers while many children were scalded due to this change. The present study aimed to propose a feasible strategy for prevention. A retrospective study was conducted for all water dispensers related pediatric burns admitted to Changhai Hospital from January 2005 to December 2009. The number of new cases and incidences of pediatric burns due to hot water from water dispensers was significantly increasing year after year. In the total 238 involved cases, 175 cases happened on males and 78.9% were at the age of 1 - 4 years. The burn areas were mainly located in upper extremities. All water dispensers in the surveyed families had no isolate protection devices and 85.2% of their locations were easy for children to reach. Nearly half of the children were in the same room with their guardians when injured. Total 196 burned children were playing the taps of water dispensers before injured, unfortunately, 80.6% of them have not been stopped until burned. As the kind of burns is quite serious and with bad outcome, some recommendations should be followed, such as buying water dispensers with protection devices, keeping children from touching them and so on.

  10. Controlling Aphelenchoides subtenuis nematodes with a hot water treatment in Crocus and Allium

    OpenAIRE

    Leeuwen, Van, P.J.; Trompert, J.P.T.

    2011-01-01

    Several bulbous crops like Crocus, Allium and some species of Tulipa and Narcissus can be infected with the nematode Aphelenchoides subtenuis. The nematodes cause retarded growth, poor or no flowering and eventually death of the bulbs and corms. A hot water treatment after lifting the bulbs has proved to be effective in controlling the nematodes. Due to a high incidence of infected stocks of bulbs a study was conducted to establish if the efficacy of the treatment could be improved by alterin...

  11. Some problems connected with the centralized production of domestic hot water

    Energy Technology Data Exchange (ETDEWEB)

    Cirillo, E.; Lazzarin, R.; Piccininni, F.; Caliari, R. (Bari Univ. (Italy). Ist. di Fisica Tecnica ed Impianti Termotecnici)

    1988-12-01

    In the course of an experimental study carried out on a centralized plant (4 boilers x 27 kW with two 2.6 cubic meters/h return pumps) supplying domestic hot water to 13 condominiums, the energy costs of recirculation were analyzed. Since the losses due to recirculation were of the same order as the useful energy, the influence of the various parameters on the losses was studied and some methods to lower them were proposed.

  12. Energy analysis of a central domestic hot water heating system equipped with condensing boilers

    Energy Technology Data Exchange (ETDEWEB)

    Cirillo, E.; Lazzarin, R.; Piccininni, F. (Bologna Univ. (Italy). Ist. di Fisica); Caliari, R. (Servizio Energia, Provincia Autonoma di Trento (IT))

    1990-01-01

    An experimental study was carried out on a central plant for the heating of domestic hot water for a block of 143 flats and 15 offices. The behaviour of the condensing boilers serving the plant was examined and the energy costs of recirculation and distribution were analysed. Since the losses due to recirculation are of the same order as the useful energy, the influence of the various parameters on the losses has been studied, and some methods of lowering them are proposed. (author).

  13. Identification of Legionella in the Hot Water Supply of a General Hospital in Isfahan

    OpenAIRE

    H Movahedian Attar; M R Shahmansouri; A A Neshat; M Fazeli

    2004-01-01

    Background: Legionella is a gram negative, aerobic, and sporeless bacterium which is readily found in ventilation systems, cooling towers, hot water distribution systems, bathrooms, swimming pools, and fountains. Legionella is implicated in the legionnaires’ and Pontiac fever diseases. Hospitals are common habitats for the bacterium, where the bacterial growths are amply found and that provide the most likely places for susceptible people to contract the diseases. Given the importance of hosp...

  14. Implications of the modelling of stratified hot water storage tanks in the simulation of CHP plants

    Energy Technology Data Exchange (ETDEWEB)

    Campos Celador, A., E-mail: alvaro.campos@ehu.es [ENEDI Research Group-University of the Basque Country, Departamento de Maquinas y Motores Termicos, E.T.S.I. de Bilbao Alameda de Urquijo, s/n 48013 Bilbao, Bizkaia (Spain); Odriozola, M.; Sala, J.M. [ENEDI Research Group-University of the Basque Country, Departamento de Maquinas y Motores Termicos, E.T.S.I. de Bilbao Alameda de Urquijo, s/n 48013 Bilbao, Bizkaia (Spain)

    2011-08-15

    Highlights: {yields} Three different modelling approaches for simulation of hot water tanks are presented. {yields} The three models are simulated within a residential cogeneration plant. {yields} Small differences in the results are found by an energy and exergy analysis. {yields} Big differences between the results are found by an advanced exergy analysis. {yields} Results on the feasibility study are explained by the advanced exergy analysis. - Abstract: This paper considers the effect that different hot water storage tank modelling approaches have on the global simulation of residential CHP plants as well as their impact on their economic feasibility. While a simplified assessment of the heat storage is usually considered in the feasibility studies of CHP plants in buildings, this paper deals with three different levels of modelling of the hot water tank: actual stratified model, ideal stratified model and fully mixed model. These three approaches are presented and comparatively evaluated under the same case of study, a cogeneration plant with thermal storage meeting the loads of an urbanisation located in the Bilbao metropolitan area (Spain). The case of study is simulated by TRNSYS for each one of the three modelling cases and the so obtained annual results are analysed from both a First and Second-Law-based viewpoint. While the global energy and exergy efficiencies of the plant for the three modelling cases agree quite well, important differences are found between the economic results of the feasibility study. These results can be predicted by means of an advanced exergy analysis of the storage tank considering the endogenous and exogenous exergy destruction terms caused by the hot water storage tank.

  15. A continuum from clear to cloudy hot-Jupiter exoplanets without primordial water depletion.

    Science.gov (United States)

    Sing, David K; Fortney, Jonathan J; Nikolov, Nikolay; Wakeford, Hannah R; Kataria, Tiffany; Evans, Thomas M; Aigrain, Suzanne; Ballester, Gilda E; Burrows, Adam S; Deming, Drake; Désert, Jean-Michel; Gibson, Neale P; Henry, Gregory W; Huitson, Catherine M; Knutson, Heather A; des Etangs, Alain Lecavelier; Pont, Frederic; Showman, Adam P; Vidal-Madjar, Alfred; Williamson, Michael H; Wilson, Paul A

    2016-01-07

    Thousands of transiting exoplanets have been discovered, but spectral analysis of their atmospheres has so far been dominated by a small number of exoplanets and data spanning relatively narrow wavelength ranges (such as 1.1-1.7 micrometres). Recent studies show that some hot-Jupiter exoplanets have much weaker water absorption features in their near-infrared spectra than predicted. The low amplitude of water signatures could be explained by very low water abundances, which may be a sign that water was depleted in the protoplanetary disk at the planet's formation location, but it is unclear whether this level of depletion can actually occur. Alternatively, these weak signals could be the result of obscuration by clouds or hazes, as found in some optical spectra. Here we report results from a comparative study of ten hot Jupiters covering the wavelength range 0.3-5 micrometres, which allows us to resolve both the optical scattering and infrared molecular absorption spectroscopically. Our results reveal a diverse group of hot Jupiters that exhibit a continuum from clear to cloudy atmospheres. We find that the difference between the planetary radius measured at optical and infrared wavelengths is an effective metric for distinguishing different atmosphere types. The difference correlates with the spectral strength of water, so that strong water absorption lines are seen in clear-atmosphere planets and the weakest features are associated with clouds and hazes. This result strongly suggests that primordial water depletion during formation is unlikely and that clouds and hazes are the cause of weaker spectral signatures.

  16. Reduction of the applied load by prioritizing hot water production; Reducering av anslutningseffekten med hjaelp av VV-prioritering

    Energy Technology Data Exchange (ETDEWEB)

    Selinder, Patrik [ZW Energiteknik, Nykoeping (Sweden)

    2005-11-01

    The energy used in Swedish district heating networks is primarily used for heating purposes in buildings, whereas the energy used for heating the domestic hot water is a minor part - about 10 to 20 % - of the total energy used in district heating systems. However, as the involved heat capacity is concerned, both heating of hot water and heating of buildings are very often of comparable sizes. Although effect of simultaneity of hot water consumption reduces the total hot water heating capacity in the built environment, the behaviour pattern of the customers is such that the hot water use results in high hot water loads for a given building at certain hours of a day. The preparation of domestic hot water therefore makes large demands on the heating capacity of the district heating net in relation to the ability of repayment due to the energy consumption. However, a building exhibits in general a good possibility for decreasing the total heat load by involving its thermal mass and therefore borrowing under limited time a part of its house heating capacity for hot water heating purposes. The thermal mass of the building ensures that this 'capacity-borrowing' is not experienced as a decrease in comfort. The goal of this project was to develop and to test a control algorithm acting on the control system of a customer substation with the purpose of temporarily reduce the heat delivery when high hot water demands occur. This algorithm has then been tested in a residential building in Goeteborg, Sweden. The control principle was applied on a Swedish customer substation with two heat exchangers connected in parallel for both radiator heating and instantaneous domestic hot water preparation. The basic idea was to reduce the opening angle of the radiator valve when a larger demand of hot water occurs (indicated by opening of the hot water control valve). A control algorithm based on certain physical parameters calculates in this case the closing angle of the radiator

  17. Effect of hot-water extraction on alkaline pulping of bagasse.

    Science.gov (United States)

    Lei, Yichao; Liu, Shijie; Li, Jiang; Sun, Runcang

    2010-01-01

    The effect of hot-water extraction on alkaline pulping was investigated. The properties of black liquor and pulp strength of bagasse were analyzed. The extraction was conducted at 160 degrees C for 30min where 13.2% of the mass was dissolved in the extraction liquor. Untreated bagasse and extracted bagasse were digested by soda and soda-AQ processes at 17% and 15.5% (with 0.1% AQ) alkali charge (NaOH). Cooking temperatures were 160 degrees C and 155 degrees C respectively. The pulp from extracted bagasse had a lower Kappa number and a higher viscosity compared to the pulp from the untreated bagasse. The black liquor from pulping extracted bagasse had a lower solid content, a lower viscosity and a lower silica content, but a higher heating value than that from pulping of untreated bagasse. Hot-water extraction resulted in a significant decrease in bleaching chemical consumption and the formation of chlorinated organics. Pulp strength properties such as the tensile index and the burst index were found to be lower, but the tear index, bulk, opacity and pulp freeness were found to be higher when hot-water extraction was applied. Copyright 2010 Elsevier Inc. All rights reserved.

  18. Control Strategies to Reduce the Energy Consumption of Central Domestic Hot Water Systems

    Energy Technology Data Exchange (ETDEWEB)

    Dentz, Jordan [The Levy Partnership, Inc., New York, NY (United States). Advanced Residential Integrated Energy Solutions; Ansanelli, Eric [The Levy Partnership, Inc., New York, NY (United States). Advanced Residential Integrated Energy Solutions; Henderson, Hugh [The Levy Partnership, Inc., New York, NY (United States). Advanced Residential Integrated Energy Solutions; Varshney, Kapil [The Levy Partnership, Inc., New York, NY (United States). Advanced Residential Integrated Energy Solutions

    2016-06-23

    Domestic hot water (DHW) heating is the second largest energy end use in U.S. buildings, exceeded only by space conditioning. Recirculation systems consisting of a pump and piping loop(s) are commonly used in multifamily buildings to reduce wait time for hot water at faucets; however, constant pumping increases energy consumption by exposing supply and return line piping to continuous heat loss, even during periods when there is no demand for hot water. In this study, ARIES installed and tested two types of recirculation controls in a pair of buildings in order to evaluate their energy savings potential. Demand control, temperature modulation controls, and the simultaneous operation of both were compared to the baseline case of constant recirculation. Additionally, interactive effects between DHW control fuel reductions and space conditioning (heating and cooling) were estimated in order to make more realistic predictions of the payback and financial viability of retrofitting DHW systems with these controls. Results showed that DHW fuel consumption reduced by 7% after implementing the demand control technique, 2% after implementing temperature modulation, and 15% after implementing demand control and temperature modulation techniques simultaneously; recirculation pump runtime was reduced to 14 minutes or less per day. With space heating and cooling interactions included, the estimated annual cost savings were 8%, 1%, and 14% for the respective control techniques. Possible complications in the installation, commissioning and operation of the controls were identified and solutions offered.

  19. Control Strategies to Reduce the Energy Consumption of Central Domestic Hot Water Systems

    Energy Technology Data Exchange (ETDEWEB)

    Dentz, Jordan; Ansanelli, Eric; Henderson, Hugh; Varshney, Kapil

    2016-06-03

    Domestic hot water (DHW) heating is the second largest energy end use in U.S. buildings, exceeded only by space conditioning. Recirculation systems consisting of a pump and piping loop(s) are commonly used in multifamily buildings to reduce wait time for hot water at faucets; however, constant pumping increases energy consumption by exposing supply and return line piping to continuous heat loss, even during periods when there is no demand for hot water. In this study, ARIES installed and tested two types of recirculation controls in a pair of buildings in order to evaluate their energy savings potential. Demand control, temperature modulation controls, and the simultaneous operation of both were compared to the baseline case of constant recirculation. Additionally, interactive effects between DHW control fuel reductions and space conditioning (heating and cooling) were estimated in order to make more realistic predictions of the payback and financial viability of retrofitting DHW systems with these controls. Results showed that DHW fuel consumption reduced by 7% after implementing the demand control technique, 2% after implementing temperature modulation, and 15% after implementing demand control and temperature modulation techniques simultaneously; recirculation pump runtime was reduced to 14 minutes or less per day. With space heating and cooling interactions included, the estimated annual cost savings were 8%, 1%, and 14% for the respective control techniques. Possible complications in the installation, commissioning and operation of the controls were identified and solutions offered.

  20. Applicability assessment of central and solar hot water systems integration in Serbia

    Directory of Open Access Journals (Sweden)

    Kljajić Miroslav V.

    2012-01-01

    Full Text Available Energy systems for consumers’ supply with sanitary hot water (SHW can be considered as a separate category of the system with many similar functions, performances and integral elements. This similarity of energy systems for SHW supply and the way in which they are used enable systemic planning, proposing and undertaking measures for improvements and advancements. This is possible not only by the reconstruction and modernization of existing technological solutions but also by their replacement with new, modern and more efficient solutions. The basic idea and the aim of this paper is the development of a concept for integrated and upgraded system of SHW supply for different types of buildings from residential to more complex buildings intended for different purposes. The analysis is based on the application of a systemic approach adapted to the conditions in urban communities and includes only modern but commercial technologies. This paper presents the results of a net energy analysis of integrated central and solar hot water supply system and compares it with the conventional sanitary hot water system in the City of Novi Sad, Serbia. The proposed methodology is demonstrated through a simulation example. It is shown that 23% reduction in the total system’s costs can be achieved as compared to the existing solution. Also, the methodology is applied to a residential block as a unit and obtained results indicate that investments in the development and construction of integrated systems are justified.

  1. Effects of Disinfection on Legionella spp., Eukarya, and Biofilms in a Hot Water System

    Science.gov (United States)

    Moletta-Denat, Marina; Frère, Jacques; Onillon, Séverine; Trouilhé, Marie-Cécile; Robine, Enric

    2012-01-01

    Legionella species are frequently detected in hot water systems, attached to the surface as a biofilm. In this work, the dynamics of Legionella spp. and diverse bacteria and eukarya associated together in the biofilm, coming from a pilot scale 1 system simulating a real hot water system, were investigated throughout 6 months after two successive heat shock treatments followed by three successive chemical treatments. Community structure was assessed by a fingerprint technique, single-strand conformation polymorphism (SSCP). In addition, the diversity and dynamics of Legionella and eukarya were investigated by small-subunit (SSU) ribosomal cloning and sequencing. Our results showed that pathogenic Legionella species remained after the heat shock and chemical treatments (Legionella pneumophila and Legionella anisa, respectively). The biofilm was not removed, and the bacterial community structure was transitorily affected by the treatments. Moreover, several amoebae had been detected in the biofilm before treatments (Thecamoebae sp., Vannella sp., and Hartmanella vermiformis) and after the first heat shock treatment, but only H. vermiformis remained. However, another protozoan affiliated with Alveolata, which is known as a host cell for Legionella, dominated the eukaryal species after the second heat shock and chemical treatment tests. Therefore, effective Legionella disinfection may be dependent on the elimination of these important microbial components. We suggest that eradicating Legionella in hot water networks requires better study of bacterial and eukaryal species associated with Legionella in biofilms. PMID:22820326

  2. Building America Case Study: Control Retrofits for Multifamily Domestic Hot Water Recirculation Systems, Brooklyn, New York

    Energy Technology Data Exchange (ETDEWEB)

    2016-12-01

    Domestic hot water (DHW) heating is the second largest energy end use in U.S. buildings, exceeded only by space conditioning. Recirculation systems consisting of a pump and piping loop(s) are commonly used in multifamily buildings to reduce wait time for hot water at faucets; however, constant pumping increases energy consumption by exposing supply and return line piping to continuous heat loss, even during periods when there is no demand for hot water. In this study, ARIES installed and tested two types of recirculation controls in a pair of buildings in order to evaluate their energy savings potential. Demand control, temperature modulation controls, and the simultaneous operation of both were compared to the baseline case of constant recirculation. Additionally, interactive effects between DHW control fuel reductions and space conditioning (heating and cooling) were estimated in order to make more realistic predictions of the payback and financial viability of retrofitting DHW systems with these controls. Results showed that DHW fuel consumption reduced by 7 percent after implementing the demand control technique, 2 percent after implementing temperature modulation, and 15 percent after implementing demand control and temperature modulation techniques simultaneously; recirculation pump runtime was reduced to 14 minutes or less per day. With space heating and cooling interactions included, the estimated annual cost savings were 8 percent, 1 percent, and 14 percent for the respective control techniques. Possible complications in the installation, commissioning and operation of the controls were identified and solutions offered.

  3. Building America Case Study: Control Retrofits for Multifamily Domestic Hot Water Recirculation Systems, Brooklyn, New York

    Energy Technology Data Exchange (ETDEWEB)

    J. Dentz; E. Ansanelli, H. Henderson, Jr.; K. Varshney

    2016-12-01

    Domestic hot water (DHW) heating is the second largest energy end use in U.S. buildings, exceeded only by space conditioning. Recirculation systems consisting of a pump and piping loop(s) are commonly used in multifamily buildings to reduce wait time for hot water at faucets; however, constant pumping increases energy consumption by exposing supply and return line piping to continuous heat loss, even during periods when there is no demand for hot water. In this study, ARIES installed and tested two types of recirculation controls in a pair of buildings in order to evaluate their energy savings potential. Demand control, temperature modulation controls, and the simultaneous operation of both were compared to the baseline case of constant recirculation. Additionally, interactive effects between DHW control fuel reductions and space conditioning (heating and cooling) were estimated in order to make more realistic predictions of the payback and financial viability of retrofitting DHW systems with these controls. Results showed that DHW fuel consumption reduced by 7% after implementing the demand control technique, 2% after implementing temperature modulation, and 15% after implementing demand control and temperature modulation techniques simultaneously; recirculation pump runtime was reduced to 14 minutes or less per day. With space heating and cooling interactions included, the estimated annual cost savings were 8%, 1%, and 14% for the respective control techniques. Possible complications in the installation, commissioning and operation of the controls were identified and solutions offered.

  4. Chemical analyses of waters from geysers, hot springs, and pools in Yellowstone National Park, Wyoming from 1974 to 1978

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, J.M.; Yadav, S.

    1979-01-01

    Waters from geysers, hot springs, and pools of Yellowstone National Park have been analyzed. We report 422 complete major ion analyses from 330 different locations of geysers, hot springs, and pools, collected from 1974 to 1978. Many of the analyses from Upper, Midway, Lower, and Norris Geyser Basin are recollections of features previously reported.

  5. Solar heating and hot water system installed at Shoney's Restaurant, North Little Rock, Arkansas. Final report

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-08-01

    The solar heating system is designed to supply a major portion of the space and water heating requirements for a newly built Shoney's Big Boy Restaurant which was installed with completion occurring in December 1979. The restaurant has a floor space of approximately 4,650 square feet and requires approximately 1500 gallons of hot water daily. The solar energy system consists of 1,428 square feet of Chamberlain flat plate liquid collector subsystem, and a 1500 gallon storage subsystem circulating hot water producing 321 x 10/sup 6/ Btu/yr (specified) building heating and hot water heating. Designer - Energy Solutions, Incorporated. Contractor - Stephens Brothers, Incorporated. This report includes extracts from site files, specification references for solar modifications to existing building heating and hot water systems, drawings installation, operation and maintenance instructions.

  6. Performance Analysis of a Hot Water Supply System with a CO2 Heat Pump by Numerical Simulation

    Science.gov (United States)

    Yokoyama, Ryohei; Shimizu, Takeshi; Takemura, Kazuhisa; Ito, Koichi

    Heat pumps using CO2 as a natural refrigerant have been developed and are expected to contribute to energy saving in hot water supply. In residential applications, CO2 heat pumps are used in combination with hot water storage tanks. The objective of this series of papers is to analyze the overall performance of a hot water supply system composed of a CO2 heat pump and a hot water storage tank by numerical simulation. In the 1st report, a simulation model of a CO2 heat pump is created based on thermodynamic equations and measured data for an existing CO2 heat pump. In addition, the performance of a CO2 heat pump is clarified in relation to the air temperature as well as the inlet and outlet water temperatures.

  7. Side-by-Side Testing of Water Heating Systems: Results from the 2013–2014 Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Colon, Carlos [Florida Solar Energy Center, Cocoa, FL (United States)

    2017-07-01

    The Florida Solar Energy Center (FSEC) completed a fourth year-long evaluation on residential hot water heating systems in a laboratory environment (east central Florida, hot-humid climate). The evaluation studied the performance of five hot water systems (HWS) plus a reference baseline system for each fuel, (i.e., electric and natural gas). Electric HWS consisted of two residential electric heat pump water heaters (HPWHs, 60 and 80 gallons), a solar thermal system using a polymer absorber (glazed) collector with 80-gallon storage and a duplicate 50-gallon standard electric water heater with added cap and wrap insulation. Baseline performance data were collected from a standard 50-gallon electric water heater of minimum code efficiency to compare energy savings. Similarly, a standard 40-gallon upright vented natural gas water heater served as baseline for the natural gas fuel category. The latter, having a larger jacket diameter [18 in., with an energy factor (EF) of 0.62] with increased insulation, replaced a former baseline (17 in. diameter, EF = 0.59) that served during three previous testing rotations (2009–2013). A high-efficiency, condensing natural gas hybrid water heater with 27-gallon buffered tank was also tested and compared against the gas baseline. All systems underwent testing simultaneously side-by-side under the criteria specified elsewhere in this report.

  8. Tuning The Laser Heater Undulator

    Energy Technology Data Exchange (ETDEWEB)

    Wolf, Zackary

    2010-12-03

    The laser heater undulator for the LCLS requires different tuning techniques than the main undulators. It is a pure permanent magnet (PPM) undulator, rather than the hybrid design of the main undulators. The PPM design allows analytic calculation of the undulator fields. The calculations let errors be introduced and correction techniques be derived. This note describes how the undulator was modelled, and the methods which were found to correct potential errors in the undulator. The laser heater undulator for the LCLS is a pure permanent magnet device requiring different tuning techniques than the main undulators. In this note, the laser heater undulator is modelled and tuning techniques to compensate various errors are derived.

  9. The Simulation of the Influence of Water Remnants on a Hot Rolled Plate after Cooling

    Directory of Open Access Journals (Sweden)

    Radek Zahradník

    2012-01-01

    Full Text Available In situations when a sheet metal plate of large dimensions is rolled, water remnants from cooling can be observed on the upper side of the plate. This paper focuses on deformations of a hot rolled sheet metal plate that are caused by water remnants after cooling. A transient finite element simulation was used to describe shape deformations of the cross profile of a metal sheet. The finite element model is fully parametric for easy simulation of multiple cases. The results from previous work were used for the boundary conditions.

  10. Theoretical analysis and experimental verification of parabolic trough solar collector with hot water generation system

    Directory of Open Access Journals (Sweden)

    Valan-Arasu Amirtham

    2007-01-01

    Full Text Available The modeling of a parabolic trough collector with hot water generation system with a well-mixed type storage tank using a computer simulation program is presented in this paper. This is followed by an experimental verification of the model and an analysis of the experimental results. The maximum difference between the predicted and the actual storage tank water temperature values is found as 9.59% only. This variation is due to the difference between the actual weather during the test period compared to hourly values and the convection losses from the collector receiver, which were not constant as accounted by the computer simulation program. .

  11. Multielement geochemistry of solid materials in geothermal systems and its applications. Part 1. Hot-water system at the Roosevelt Hot Springs KGRA, Utah

    Energy Technology Data Exchange (ETDEWEB)

    Bamford, R.W.; Christensen, O.D.; Capuano, R.M.

    1980-02-01

    Geochemical studies of the geothermal system at Roosevelt Hot Springs, Utah, have led to development of chemical criteria for recognition of major features of the system and to a three-dimensional model for chemical zoning in the system. Based on this improved level of understanding several new or modified geochemical exploration and assessment techniques have been defined and are probably broadly applicable to evaluation of hot-water geothermal systems. The main purpose of this work was the development or adaptation of solids geochemical exploration techniques for use in the geothermal environment. (MHR)

  12. Protection Heater Design Validation for the LARP Magnets Using Thermal Imaging

    CERN Document Server

    Marchevsky, M; Cheng, D W; Felice, H; Sabbi, G; Salmi, T; Stenvall, A; Chlachidze, G; Ambrosio, G; Ferracin, P; Izquierdo Bermudez, S; Perez, J C; Todesco, E

    2016-01-01

    Protection heaters are essential elements of a quench protection scheme for high-field accelerator magnets. Various heater designs fabricated by LARP and CERN have been already tested in the LARP high-field quadrupole HQ and presently being built into the coils of the high-field quadrupole MQXF. In order to compare the heat flow characteristics and thermal diffusion timescales of different heater designs, we powered heaters of two different geometries in ambient conditions and imaged the resulting thermal distributions using a high-sensitivity thermal video camera. We observed a peculiar spatial periodicity in the temperature distribution maps potentially linked to the structure of the underlying cable. Two-dimensional numerical simulation of heat diffusion and spatial heat distribution have been conducted, and the results of simulation and experiment have been compared. Imaging revealed hot spots due to a current concentration around high curvature points of heater strip of varying cross sections and visuali...

  13. The lethality of hot water and ozone to aquatic invasive species

    Science.gov (United States)

    Buley, Riley

    2017-01-01

    The spread of Aquatic Invasive Species (AIS) between the Great Lakes and Mississippi River Basin by way of the Chicago Area Waterway System (CAWS) is a pressing concern to resource managers in the Midwest region. Augmenting this spread are watercrafts traveling through the CAWS locks and dams. AIS are able to attach to boat hulls, equipment, or are present in the surrounding water during lock transfers. It has been proposed that chemically treating boats during lock transfers would be an effective way to reduce the spread of AIS. Of a range of treatments identified as candidates to do this, hot water and dissolved ozone ranked high as effective treatments causing the least amount of environmental impact. This study assessed the lethality of hot water and dissolved ozone, separately and in combination, on select AIS in a laboratory setting. Species were exposed to water temperatures ranging from 18 to 50°C, ozone concentrations ranging from 0 to 920 ORP (Oxidation-Reduction Potential), and exposure durations ranging from 10 to 60 min to find treatments capable of inducing 100% mortality. Results indicated that water at 45°C achieved 100% mortality in all species tested with a 10 min exposure. Ozone concentrations induced significant mortality to all species tested, particularly when combined with elevated temperatures.

  14. Bait Insecticides and Hot Water Drenches Against the Little Fire Ant, Wasmannia auropunctata (Hymenoptera: Formicidae), Infesting Containerized Nursery Plants

    National Research Council Canada - National Science Library

    Arnold H. Hara; Susan K. Cabral; Ruth Y. Niino-Duponte; Christopher M. Jacobsen; Kyle Onuma

    2011-01-01

    ABSTRACT Broadcasts of hydramethylnon, S-methoprene, and metaflumizone baits, metaflumizone spray, and hot water drenching were evaluated for their efficacy against the little fire ant, Wasmannia auropunctata (Roger...

  15. Effect of hot water treatment of beef trimmings on processing characteristics and eating quality of ground beef.

    Science.gov (United States)

    Pietrasik, Z; Gaudette, N J; Klassen, M

    2016-03-01

    The effect of hot water treatment of beef trimmings on the processing characteristics, shelf-life and consumer acceptability of ground beef was evaluated. Hot water treatment (85°C for 40s) substantially enhanced the microbial quality of trimmings during refrigerated storage and this was independent of the fat level of the trimmings. Treatment had no effect on the oxidative stability of trimmings stored up to 7days, ground beef displayed in a retail cabinet for up to 3days, and had minimal effect on textural properties. Instrumental results demonstrate that ground beef from hot water treated trimmings was slightly lighter and tended to have less red color compared to non-treated beef. These color differences did not impact the consumer acceptance of raw patties, and in addition, hot water treatment did not significantly affect the consumer acceptability of cooked patty attributes. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

  16. Combined Active and Passive Solar Space Heating and Solar Hot Water Systems for an Elementary School in Boise, Idaho.

    Science.gov (United States)

    Smull, Neil A.; Armstrong, Gerald L.

    1979-01-01

    Amity Elementary School in Boise, Idaho, features a solar space heating and domestic hot water system along with an earth covering to accommodate the passive aspects of energy conservation. (Author/MLF)

  17. Protein binding hot spots and the residue-residue pairing preference: a water exclusion perspective

    Directory of Open Access Journals (Sweden)

    Li Jinyan

    2010-05-01

    Full Text Available Abstract Background A protein binding hot spot is a small cluster of residues tightly packed at the center of the interface between two interacting proteins. Though a hot spot constitutes a small fraction of the interface, it is vital to the stability of protein complexes. Recently, there are a series of hypotheses proposed to characterize binding hot spots, including the pioneering O-ring theory, the insightful 'coupling' and 'hot region' principle, and our 'double water exclusion' (DWE hypothesis. As the perspective changes from the O-ring theory to the DWE hypothesis, we examine the physicochemical properties of the binding hot spots under the new hypothesis and compare with those under the O-ring theory. Results The requirements for a cluster of residues to form a hot spot under the DWE hypothesis can be mathematically satisfied by a biclique subgraph if a vertex is used to represent a residue, an edge to indicate a close distance between two residues, and a bipartite graph to represent a pair of interacting proteins. We term these hot spots as DWE bicliques. We identified DWE bicliques from crystal packing contacts, obligate and non-obligate interactions. Our comparative study revealed that there are abundant unique bicliques to the biological interactions, indicating specific biological binding behaviors in contrast to crystal packing. The two sub-types of biological interactions also have their own signature bicliques. In our analysis on residue compositions and residue pairing preferences in DWE bicliques, the focus was on interaction-preferred residues (ipRs and interaction-preferred residue pairs (ipRPs. It is observed that hydrophobic residues are heavily involved in the ipRs and ipRPs of the obligate interactions; and that aromatic residues are in favor in the ipRs and ipRPs of the biological interactions, especially in those of the non-obligate interactions. In contrast, the ipRs and ipRPs in crystal packing are dominated by

  18. Protein binding hot spots and the residue-residue pairing preference: a water exclusion perspective.

    Science.gov (United States)

    Liu, Qian; Li, Jinyan

    2010-05-12

    A protein binding hot spot is a small cluster of residues tightly packed at the center of the interface between two interacting proteins. Though a hot spot constitutes a small fraction of the interface, it is vital to the stability of protein complexes. Recently, there are a series of hypotheses proposed to characterize binding hot spots, including the pioneering O-ring theory, the insightful 'coupling' and 'hot region' principle, and our 'double water exclusion' (DWE) hypothesis. As the perspective changes from the O-ring theory to the DWE hypothesis, we examine the physicochemical properties of the binding hot spots under the new hypothesis and compare with those under the O-ring theory. The requirements for a cluster of residues to form a hot spot under the DWE hypothesis can be mathematically satisfied by a biclique subgraph if a vertex is used to represent a residue, an edge to indicate a close distance between two residues, and a bipartite graph to represent a pair of interacting proteins. We term these hot spots as DWE bicliques. We identified DWE bicliques from crystal packing contacts, obligate and non-obligate interactions. Our comparative study revealed that there are abundant unique bicliques to the biological interactions, indicating specific biological binding behaviors in contrast to crystal packing. The two sub-types of biological interactions also have their own signature bicliques. In our analysis on residue compositions and residue pairing preferences in DWE bicliques, the focus was on interaction-preferred residues (ipRs) and interaction-preferred residue pairs (ipRPs). It is observed that hydrophobic residues are heavily involved in the ipRs and ipRPs of the obligate interactions; and that aromatic residues are in favor in the ipRs and ipRPs of the biological interactions, especially in those of the non-obligate interactions. In contrast, the ipRs and ipRPs in crystal packing are dominated by hydrophilic residues, and most of the anti-ipRs of

  19. Evaluation of radon in hot spring waters in Zacatecas State, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Favila R, E.; Lopez del Rio, H.; Davila R, I.; Mireles G, F., E-mail: hlopezdelrio@hotmail.co [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Calle Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico)

    2010-10-15

    It is well know that radon is a potent human carcinogen. Because of the health concern of radon exposure, concentrations of {sup 222}Rn were determined in ten hot spring water samples from the Mexican state of Zacatecas. The thermal water is collected in pools and used mainly for recreational purposes. In addition to radon level, the water samples were characterized for temperature, conductivity, and ph. Liquid scintillation spectrometry was used to measure {sup 222}Rn and its decay products by mixing directly an aliquot of water with a commercial liquid scintillation. All measurements were carried out using a liquid scintillation counter (Wallac 1411). The water temperature ranged from 28 to 59 C, while the ph varied from 7.2 to 9.0, and the water conductivity was between 202.4 and 1072 {mu}S/cm. The {sup 222}Rn concentration varied in the range 3.9-32.6 Bq/L. In addition, the risk to radon exposure was assessed by considering three -real and possible- radon exposure scenarios: 1) ingestion of bottled thermal water, 2) direct ingestion of thermal water; and 3) vapor inhalation. The annual effective dose calculated for ingestion of bottled thermal water was 0.010-0.083 mSv/yr; for ingestion of water was 0.65-5.47 mSv/yr; and for inhalation was 0.28-2.81 mSv/yr. (Author)

  20. Microbial growth in domestic hot water systems with special emphasis on connections to district heating networks

    Energy Technology Data Exchange (ETDEWEB)

    Frederiksen, S. (Lund Institute of Technology, Dept. of Heat and Power Engineering, Lund (SE)); Krongaard Kristensen, K. (Regional Food and Hygiene Authority, Koebenhavns Amt Vest, Glostrup (DK))

    1991-01-01

    It is by now well-estalished that domestic hot water systems often harbour Legionella bacteria. Measurements into a number of Danish systems have revealed many other bacteria, among them the thermophilic species Thermus, which is predominantly found on heating coils, where local temperatures are higher. This bacterium not only hampers heat transfer due to fouling, but may also be pathogenic, due to release of endotoxins. Its presence may explain a wide spectrum of symptoms experienced by people after hot baths, such as rashes and itching. The paper summarizes these findings, and on this basis engineering and microbiological considerations are presented in an effort to find ways of future control strategies that go beyond Legionella prevention. Special attention is given to district heating connections, in which low supply and return temperatures are generally wanted in the primary circuit. (author) 16 refs.

  1. Simulation Programs for Ph.D. Study of Analysis, Modeling and Optimum Design of Solar Domestic Hot Water Systems

    DEFF Research Database (Denmark)

    Qin, Lin

    1999-01-01

    The design of solar domestic hot water system is a complex process, due to characteristics inherent in solar heating technology. Recently, computer simulation has become a widely used technique to improve the understanding of the thermal processes in such systems. This report presents the detailed...... programs or units that were developed in the Ph.D study of " Analysis, Modeling and Optimum Design of Solar Domestic Hot Water Systems"....

  2. Application of solar energy to the supply of hot water for textile dyeing. Final report, CDRL/PA 10

    Energy Technology Data Exchange (ETDEWEB)

    None

    1977-09-01

    The design plan for a solar process hot water system for a textile dye beck at Riegel Textile Corporation's LaFrance, South Carolina, facilities is presented. The solar system consists of 396 GE model TC 100 evacuated tube collector modules arranged in a ground mounted array with a total collector area of 6680 square feet. The system includes an 8000-gallon hot water storage tank. Systems analyses, specification sheets, performance data, and an economic evaluation of the proposed system are presented. (WHK)

  3. Summertime hot water comfort in houses[District heating optimization]; Varmvattenkomfort sommatid i smaahus

    Energy Technology Data Exchange (ETDEWEB)

    Persson, Tommy [Lund Inst. of Technology (Sweden). Dept. of Heat and Power Engineering

    2002-07-01

    Problems with low domestic hot water temperature summertime in district heating systems in low heat density areas is studied. The study is based on dynamic simulation of a part of a district heating system. A part of the DH system in Malmoe, owned by Sydkraft Vaerme Malmoe AB, serves as source of inspiration for the computer model. The system in Malmoe is used as a reference system in the investigations. A number of different system configurations are regarded. For example, the influence of the following is investigated: the placing of thermostatic valves in the system, length of pipes, type of domestic hot water controller in the DH substations, degree of insulation of the pipes, pipe dimensions, supply temperature at the production site and also domestic hot water use. The different system configurations are optimized with respect to heat losses under the condition that an acceptable domestic hot water comfort must be secured. How to construct the domestic hot water controllers in order to achieve the best system performance is also studied in the report. The calculations show that regardless of if a thermostatic valve is installed only in the periphery of the DH system or in all DH substations there is an optimum set point at which the heat losses from the system is minimized. For all the system configurations studied in this project an acceptable domestic hot water temperature is secured at the optimum set point. It appears that under operation conditions where a good domestic hot water temperature cannot be attained in large parts of the system the characteristics of the DH substations will lead to high return temperatures. The high return temperatures lead to an increase in heat losses and such operation conditions cannot coincide with an optimum set point regarding heat losses from the system. For both alternatives regarding the location of the thermostatic valve(s) the optimum set point is reduced as the length of the distribution pipes is increased. In the

  4. Technical, economic and environmental investigation of using district heating to prepare domestic hot water in Chinese multi-storey buildings

    DEFF Research Database (Denmark)

    Zhang, Lipeng; Xia, Jianjun; Thorsen, Jan Eric

    2016-01-01

    utilizes the industrial waste heat to prepare DHW via the DH network. A building model of a multi-storey building in Beijing was developed to investigate the technical feasibility. An economic evaluation was made using net present value to compare the annualized cost for individual water heaters and flat......-effective issues of the centralized DHW systems. From the perspective of long-term development, DHW produced via DH systems would be more sustainable because DH is an important precondition for an environmental safe use of domestic waste fuels. This paper presents an approach that uses flat stations meanwhile...

  5. COMPOSITION, HOT-WATER SOLUBILITY OF ELEMENTS AND NUTRITIONAL VALUE OF FRUITS AND

    Directory of Open Access Journals (Sweden)

    Julierme Zimmer Barbosa

    2015-12-01

    Full Text Available ABSTRACT Yerba mate leaves are the most studied and used parts of the tree, while fruits have been little investigated as to their elemental composition. The objective of this study was to characterize the composition, the hot-water solubility of the elements and the nutritional value of yerba mate (Ilex paraguariensis St. Hill fruits and leaves. Both fruits and leaves were collected from four yerba mate provenances (cities of Cascavel, Quedas do Iguaçu and Ivaí in Paraná state and Barão de Cotegipe in Rio Grande do Sul state 17 years of age, grown in the city of Pinhais, Paraná state, Brazil. The total and hot water-soluble contents of 22 and 20 elements, respectively, were determined. The elemental composition of the fruits presented the following decreasing order: C, K, N, Mg, Ca, P, Al, Na, Zn, Mn, Fe, Ba, Cu, Ni, Mo, Pb, Cr, As, Co, Ag, V and Cd. For the leaves the decreasing order was: C, N, K, Ca, Mg, P, Al, Mn, Na, Fe, Zn, Ba, Cu, Ni, Pb, Cr, Mo, As, Co, Ag, V and Cd. It was found than 2 to 8 elements in the fruit presented greater water solubility than in the leaves. In case of consumption via infusion of the fruits or leaves, there would be nutritive value for K, Mg, P, Mn, Cr, Mo, Cu and Zn, while consumption of capsules would have nutritive value only for Mn via the leaves. In general, the fruits have more distinct elemental composition, hot-water solubility and nutritional value than yerba mate leaves.

  6. Water requirements of breast-fed infants in a hot climate.

    Science.gov (United States)

    Almroth, S G

    1978-07-01

    To estimate the water requirements of exclusively breast-fed infants in a hot climate, theoretical calculations of water requirements were made and a field study was carried out in Jamaica. Three urine samples were collected from each of 16 infants. The specific gravity of individual urine samples ranged from 1.005 through 1.015, with a mean of 1.009 (SD +/- 0.002). Corresponding values for osmolality were calculated to be 103 through 468 mOsmole/liter with a mean of 258 mOsmole/liter. The mean specific gravity for an infant ranged from 1.006 through 1.012, or 139 through 358 mOsmole/liter. The mean outdoor temperature was 27.6 C and the humidity 76%. Because the values for specific gravity were universally low it was concluded that healthy, exclusively breast-fed infants living in a hot humid climate will manage well without additional water. Additional water may be desirable during illness.

  7. Phase change material storage heater

    Science.gov (United States)

    Goswami, D. Yogi; Hsieh, Chung K.; Jotshi, Chand K.; Klausner, James F.

    1997-01-01

    A storage heater for storing heat and for heating a fluid, such as water, has an enclosure defining a chamber therein. The chamber has a lower portion and an upper portion with a heating element being disposed within the enclosure. A tube through which the fluid flows has an inlet and an outlet, both being disposed outside of the enclosure, and has a portion interconnecting the inlet and the outlet that passes through the enclosure. A densely packed bed of phase change material pellets is disposed within the enclosure and is surrounded by a viscous liquid, such as propylene glycol. The viscous liquid is in thermal communication with the heating element, the phase change material pellets, and the tube and transfers heat from the heating element to the pellets and from the pellets to the tube. The viscous fluid has a viscosity so that the frictional pressure drop of the fluid in contact with the phase change material pellets substantially reduces vertical thermal convection in the fluid. As the fluid flows through the tube heat is transferred from the viscous liquid to the fluid flowing through the tube, thereby heating the fluid.

  8. Radioprotective Effects of Sulfurcontaining Mineral Water of Ramsar Hot Spring with High Natural Background Radiation on Mouse Bone Marrow Cells

    Directory of Open Access Journals (Sweden)

    Heidari A. H.

    2017-12-01

    Full Text Available Background: We intend to study the inhibitory effect of sulfur compound in Ramsar hot spring mineral on tumor-genesis ability of high natural background radiation. Objective: The radioprotective effect of sulfur compounds was previously shown on radiation-induced chromosomal aberration, micronuclei in mouse bone marrow cells and human peripheral lymphocyte. Ramsar is known for having the highest level of natural background radiation on Earth. This study was performed to show the radioprotective effect of sulfur-containing Ramsar mineral water on mouse bone marrow cells. Method: Mice were fed three types of water (drinking water, Ramsar radioactive water containing sulfur and Ramsar radioactive water whose sulfur was removed. Ten days after feeding, mice were irradiated by gamma rays (0, 2 and 4 Gy. 48 and 72 hours after irradiating, mice were killed and femurs were removed. Frequency of micronuclei was determined in bone marrow erythrocytes. Results: A significant reduction was shown in the rate of micronuclei polychromatic erythrocyte in sulfur-containing hot spring water compared to sulfur-free water in hot spring mineral water. Gamma irradiation induced significant increases in micronuclei polychromatic erythrocyte (MNPCE and decreases in polychromatic erythrocyte/polychromatic erythrocyte + normochromatic erythrocyte ratio (PCEs/ PCEs+NCEs (P < 0.001 in sulfur-containing hot spring water compared to sulfur-free hot spring mineral water. Also, apparently there was a significant difference between drinking water and sulfur-containing hot spring water in micronuclei polychromatic erythrocyte and polychromatic erythrocyte/polychromatic erythrocyte+ normochromatic erythrocyte ratio. Conclusion: The results indicate that sulfur-containing mineral water could result in a significant reduction in radiation-induced micronuclei representing the radioprotective effect of sulfur compounds.

  9. 'Double water exclusion': a hypothesis refining the O-ring theory for the hot spots at protein interfaces.

    Science.gov (United States)

    Li, Jinyan; Liu, Qian

    2009-03-15

    The O-ring theory reveals that the binding hot spot at a protein interface is surrounded by a ring of residues that are energetically less important than the residues in the hot spot. As this ring of residues is served to occlude water molecules from the hot spot, the O-ring theory is also called 'water exclusion' hypothesis. We propose a 'double water exclusion' hypothesis to refine the O-ring theory by assuming the hot spot itself is water-free. To computationally model a water-free hot spot, we use a biclique pattern that is defined as two maximal groups of residues from two chains in a protein complex holding the property that every residue contacts with all residues in the other group. Given a chain pair A and B of a protein complex from the Protein Data Bank (PDB), we calculate the interatomic distance of all possible pairs of atoms between A and B. We then represent A and B as a bipartite graph based on these distance information. Maximal biclique subgraphs are subsequently identified from all of the bipartite graphs to locate biclique patterns at the interfaces. We address two properties of biclique patterns: a non-redundant occurrence in PDB, and a correspondence with hot spots when the solvent-accessible surface area (SASA) of a biclique pattern in the complex form is small. A total of 1293 biclique patterns are discovered which have a non-redundant occurrence of at least five, and which each have a minimum two and four residues at the two sides. Through extensive queries to the HotSprint and ASEdb databases, we verified that biclique patterns are rich of true hot residues. Our algorithm and results provide a new way to identify hot spots by examining proteins' structural data. The biclique mining algorithm is available at http://www.ntu.edu.sg/home/jyli/dwe.html. Supplementary data are available at Bioinformatics online.

  10. ACCOUNTING FOR NONUNIFORMITY OF WATER CONSUMPTION IN THE EXHAUST AIR HEAT RECLAMATION SYSTEMS FOR HOT WATER SUPPLY

    Directory of Open Access Journals (Sweden)

    Samarin Oleg Dmitrievich

    2017-03-01

    Full Text Available This article is devoted to assessment of the influence of variation of daily hot water consumption on the predicted energy effect by using heat recovery of exhaust air in typical exhaust ventilation systems of the most commonly used flat buildings during their switch to the mechanical induction for the pre-heating of water for hot water supply. It outlines the general principle of the organization of this method of energy saving and presents the basic equations of heat transfer in the heat exchanger. The article proposes a simplified method of accounting for changes in the heat transfer coefficient of air-to-water heat exchanger with fluctuations of water demand using existing dependencies for this coefficient from the rate flow of heating and heated fluid through the device. It presents observations to identify the parameters of the real changes of water consumption during the day with the main quantitative characteristics of normally distributed random variables. Calculation of thermal efficiency of the heat exchange equipment using dimensionless parameters through the number of heat transfer under the optimal opposing scheme of fluid motion is completed under conditions of variable water flow rate for the type residential building of the П3-1/16 series using the Monte Carlo method for numerical modeling of stochastic processes. The estimation of the influence of fluctuation of the current water consumption on the instantaneous thermal efficiency factor of the heat exchanger and the total energy consumption of the building is given, and it is shown that the error of said calculation using average daily parameters is within the margin of usual engineering calculation.

  11. Analysis, modeling and optimum design of solar domestic hot water systems

    Energy Technology Data Exchange (ETDEWEB)

    Lin Qin

    1998-12-31

    The object of this study was dynamic modeling, simulation and optimum design of solar DHW (domestic hot water) systems, with respect to different whether conditions, and accurate dynamic behaviour of the heat load. Special attention was paid to systems with thermosyphon and drain-back design. The solar radiation in Beijing (China) and in Denmark are analyzed both by theoretical calculations and the analysis of long-term measurements. Based on the weather data from the Beijing Meteorological Station during the period of 1981-1993, a Beijing Test Reference Year has been formulated by means of statistical analysis. A brief introduction about the Danish Test Reference Year and the Design Reference Year is also presented. In order to investigate the heat loss as a part of the total heat load, dynamic models for distribution networks have been developed, and simulations have been carried out for typically designed distribution networks of the circulation type. The influence of operation parameters such as the tank outlet temperature, the hot-water load and the load pattern, on the heat loss from the distribution networks in presented. It was found that the tank outlet temperature has a significant influence on the heat loss from a circulation type of distribution network, while the hot-water load and the load pattern have no obvious effect. Dynamic models of drain-back tanks, both as a separated tank and combined with a mantle tank, have been developed and presented. Models of the other basic components commonly used in solar DHW systems, such as flat-plate collectors, connection pipes, storage tanks with a heat exchanger spiral, and controllers, are also described. (LN) 66 refs.

  12. The effect of common imaging and hot water maceration on DNA recovery from skeletal remains.

    Science.gov (United States)

    Frank, Emilie M; Mundorff, Amy Z; Davoren, Jon M

    2015-12-01

    Identifying human remains often begins with cleaning and imaging the material. Hot water maceration is used to remove adherent soft tissue from bone and radiographs are taken to better visualize osseous details. Heat and radiation are known to have harmful effects on DNA, but their ability to degrade DNA when used for cleaning and imaging has not been well studied. To better understand their individual and combined effects on the recoverability of DNA from bone, skeletal samples were subjected to (1) hot water maceration (62 °C for 45 min); (2) CT scanning (0.6mm slices, 120 kV, 10.4s); (3) X-ray (50 kVp, 150 mA, 0.03 s, 40 in); and (4) all 3 treatments combined. Forty-eight DNA samples were extracted, quantified and amplified with the AmpFLSTR(®) Identifiler(®) system. Nearly all of the processed samples had reduced RFU values relative to the unprocessed samples, indicating some amount of genetic loss. This loss did not always translate into loss of profile completeness, since only a few samples had a reduction in the number of loci detected after processing. DNA yields were not significantly reduced by any one of the processing methods, however the results indicate that the damaging effects are additive. It is possible that processing may reduce a bone's DNA reservoir and as more procedures are preformed, the pool of available genetic information might be diminished. Many intrinsic and extrinsic factors can affect the recoverability of DNA from bone. Collecting a DNA sample prior to processing avoids the negative effects from hot water maceration and radiological imaging. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  13. Effects of hot water treatments on dormant grapevine propagation materials used for grafted vine production

    Directory of Open Access Journals (Sweden)

    Soltekin Oguzhan

    2017-01-01

    Full Text Available Agrobacterium vitis is responsible for the crown gall disease of grapevine which breaks the grapevine trunk vascular system. Nutrient flow is prevented by crown gall and it leads to weak growth and death of the plants. It can be destructive disease often encountered in vineyards and it can be spread in cuttings for propagation. Thermotherapy treatment is an alternative method for eradicating A. vitis from grapevine cuttings but effects of thermotherapy treatments on dormant vine tissue, bud vitality, rooting and shooting of the propagation materials are not yet fully understood. In this research, it is aimed to determine the effects of thermotherapy treatment (Hot water treatment on callus formation (at the basal part and grafting point, grafted vine quality (shoot length, shoot width, root number, shooting and rooting development, fresh and dry weight of shoots and roots and final take in the grafted vine production. Experiment was conducted in the nursery of Manisa Viticultural Research Institute. Rootstocks (Kober 5BB, Couderc 1613 and 41B and scions (Sultan 7 and Manisa sultanı were hot-water treated at 50°C for 30 minutes which is the most common technique against Agrobacterium vitis. After thermotherapy treatment, all rootstocks were grafted with Sultan 7 and Manisa sultanıvarieties. They were kept for 22 days in callusing room for callus development and then they were planted in polyethlyene bags for rooting. At the end of the study, significant treatment x rootstock interaction were observed for the final take of Sultan 7 variety. Thermotherapy treated of 1613C/Sultan 7 combinations had more final take than the control (untreated group. For instance, hot water treated cuttings of 1613C/Sultan 7 combinations had 75% final take while the control group had the 70%. Also there were not observed any adverse effects of HWT on bud and tissue vitality.

  14. Thermal Energy Storage using PCM for Solar Domestic Hot Water Systems: A Review

    Science.gov (United States)

    Khot, S. A.; Sane, N. K.; Gawali, B. S.

    2012-06-01

    Thermal energy storage using phase chase materials (PCM) has received considerable attention in the past two decades for time dependent energy source such as solar energy. From several experimental and theoretical analyses that have been made to assess the performance of thermal energy storage systems, it has been demonstrated that PCM-based systems are reliable and viable options. This paper covers such information on PCMs and PCM-based systems developed for the application of solar domestic hot water system. In addition, economic analysis of thermal storage system using PCM in comparison with conventional storage system helps to validate its commercial possibility. From the economic analysis, it is found that, PCM based solar domestic hot water system (SWHS) provides 23 % more cumulative and life cycle savings than conventional SWHS and will continue to perform efficiently even after 15 years due to application of non-metallic tank. Payback period of PCM-based system is also less compared to conventional system. In conclusion, PCM based solar water heating systems can meet the requirements of Indian climatic situation in a cost effective and reliable manner.

  15. Inclusive analysis and performance evaluation of solar domestic hot water system (a case study

    Directory of Open Access Journals (Sweden)

    Mohamed Ghorab

    2017-06-01

    Full Text Available In recent years Solar Domestic Hot Water systems have increased significantly their market share. In order to better understand the real-life performance of SDHW systems, a single detached house was selected for extensive monitoring. Two solar panels were installed on the house roof to provide thermal energy to the Domestic Hot Water (DHW system. The house was equipped with data logging system and remotely monitored with performance data collected and analyzed over one year. The paper presents the inclusive analysis and performance evaluation of SDHW system, including DHW recirculation loop, under Canadian weather conditions for average family occupancy (two adults and two kids with daily average DHW, draws of 246 L. Moreover, the study is carried out a significant recommendation to improve the SDHW performance, decrease the gas energy consumption and reduce greenhouse gas (GHG emissions. The SDHW performance depends mainly on DHW flow rate, draw time and duration, city water temperature, DHW recirculation loop control strategy and system layout. The performance analysis results show that 91.5% of the collected solar energy is transferred to the DHW heating load through the solar tank. The contribution to DHW heating load is about 69.4% from natural gas and 30.6% from solar. The recirculation loop is responsible for close to 34.9%, of DHW total energy.

  16. Evaluations of different domestic hot water preparing methods with ultra-low-temperature district heating

    DEFF Research Database (Denmark)

    Yang, Xiaochen; Li, Hongwei; Svendsen, Svend

    2016-01-01

    of Legionella in the DHW (domestic hot water) and assure the comfortable temperature, all substations were installed with supplementary heating devices. Detailed measurements were taken in the substations, including the electricity demand of the supplementary heating devices. To compare the energy and economic...... performance of the substations, separate models were built based on standard assumptions. The relative heat and electricity delivered for preparing DHW were calculated. The results showed that substations with storage tanks and heat pumps have high relative electricity demand, which leads to higher integrated...

  17. Optimization of China´s centralized domestic hot water system by applying Danish elements

    DEFF Research Database (Denmark)

    Zhang, Lipeng; Gudmundsson, Oddgeir; Thorsen, Jan Eric

    2014-01-01

    a smart, energy efficient and environmentally friendly energy-consumption system. Nevertheless, the development of centralized DHW (CDHW) systems in these two countries differs significantly. This article details the challenges China’s CDHW system is currently encountering and proposes to apply the flat......Regardless of where they are in the world, people depend on a reliable and sufficient supply of domestic hot water (DHW) for daily use. Some countries that have district heating (DH) infrastructure, such as Denmark and China, combine spacing heating (SH) and DHW together, with the aim of having...

  18. Technical comparison of domestic hot water system which used in China and Denmark

    DEFF Research Database (Denmark)

    Zhang, Lipeng; Gudmundsson, Oddgeir; Thorsen, Jan Eric

    2014-01-01

    Regardless of where they are in the world, people depend on a reliable and sufficient supply of domestic hot water (DHW) for daily use. Some countries, which have district heating infrastructure, combine spacing heating (SH) and DHW together, with the aim of having a smart, energy efficient...... and environmentally friendly energy-consumption system, such as Denmark and China. Nevertheless, the development of DHW networks in these two countries differs significantly. This article detailed the comparisons in technical aspect: common preparation methods of DHW through district heating was introduced in China...

  19. Optimization of China's centralized domestic hot water system by applying Danish elements

    DEFF Research Database (Denmark)

    Zhang, Lipeng; Gudmundsson, Oddgeir; Thorsen, Jan Eric

    2014-01-01

    a smart, energy efficient and environmentally friendly energy-consumption system. Nevertheless, the development of centralized DHW (CDHW) systems in these two countries differs significantly. This article details the challenges China's CDHW system is currently encountering and proposes to apply the flat......Regardless of where they are in the world, people depend on a reliable and sufficient supply of domestic hot water (DHW) for daily use. Some countries that have district heating (DH) infrastructure, such as Denmark and China, combine spacing heating (SH) and DHW together, with the aim of having...

  20. Glucose reactions with acid and base catalysts in hot compressed water at 473 K.

    Science.gov (United States)

    Watanabe, Masaru; Aizawa, Yuichi; Iida, Toru; Aida, Taku M; Levy, Caroline; Sue, Kiwamu; Inomata, Hiroshi

    2005-09-05

    The effects of the homogeneous catalysts (H(2)SO(4) and NaOH) and heterogeneous catalysts (TiO(2) and ZrO(2)) on glucose reactions were examined in hot compressed water (473 K) by a batch-type reactor. From the homogeneous catalyst studies, we confirmed that the acid catalyst promoted dehydration, while isomerization of glucose to fructose was catalyzed by alkali. Anatase TiO(2) was found to act as an acid catalyst to promote formation of 5-hydroxymethylfuraldehyde (HMF). Zirconia (ZrO(2)) was a base catalyst to promote the isomerization of glucose. The effects of the additives were also confirmed through fructose reactions.

  1. Hot water irrigation as treatment for intractable posterior epistaxis in an out-patient setting.

    Science.gov (United States)

    Novoa, E; Schlegel-Wagner, C

    2012-01-01

    The management of intractable posterior epistaxis is challenging for any physician. Nasal packing, often combined with use of an endonasal balloon system, is painful for the patient, and torturous to maintain for two to three days. If conservative treatment fails, the most commonly used treatment options are currently invasive procedures such as endoscopic coagulation of bleeding arteries, external ligation and, rarely, embolisation. This paper describes a simple, non-invasive technique of treating posterior epistaxis with hot water irrigation. Technical information is presented, and the benefits of the method are discussed.

  2. Hot Water Extract of Leather Carp (Cyprinus carpio nudus) Improves Exercise Performance in Mice.

    Science.gov (United States)

    Lee, Gong-Hyeon; Harwanto, Dicky; Park, Sun-Mee; Choi, Jae-Suk; Kim, Mi-Ryung; Hong, Yong-Ki

    2015-12-01

    The hot water extract of leather carp (Cyprinus carpio nudus) has been used as a nourishing tonic soup and as an aid for recovery from physical fatigue. In this study, we investigated the effect of leather carp extract on exercise performance in mice. Swimming endurance and forelimb grip strength were assessed following oral administration of the extract (once per day for 7 days) at a dose of 0.5 mg/10 μL/g body weight. After 7 days, mice given the leather carp extract had significantly greater swimming endurance [105±18 s (Pleather carp extract can improve physical exercise performance and prevent oxidative stress caused by exhaustive workouts.

  3. Solar heating and hot water system installed at James Hurst Elementary School, Portsmouth, Virginia

    Science.gov (United States)

    1981-01-01

    Solar heating and a hot water system installed in an elementary school in Portsmouth, Virginia are examined. The building is zoned into four heating/cooling areas. Each area is equipped with an air handling unit that is monitored and controlled by central control and monitoring system. The solar system for the building uses a collector area of 3,630 sq. ft. of flat plate liquid collectors, and a 6,000 gallon storage tank. System descriptions, maintenance reports, detailed component specifications, and design drawings to evaluate this solar system are reported.

  4. Study on the behavior and mechanism of polycarbonate with hot-water aging

    Science.gov (United States)

    Kong, L. P.; Zhao, Y. X.; Zhou, C. H.; Huang, Y. H.; Tang, M.; Gao, J. G.

    2016-07-01

    The present work was concerned with hot-water aging behavior and mechanism of Bisphenol A polycarbonate (PC) used as food and packaging materials. It indicated that with the aging time prolonged, PC sample had internal defects and the mechanical properties of PC materials changed not too much, molecular weight decreased, thermal stability declined. Phenolic hydroxyl absorption intensity enhanced in IR spectra and the maximum absorption wavelength red shift of benzene in UV-Vis spectra, the level of BPA increased. The color change of PC sample was not apparent.

  5. Invaders in hot water: a simple decontamination method to prevent the accidental spread of aquatic invasive non-native species.

    Science.gov (United States)

    Anderson, Lucy G; Dunn, Alison M; Rosewarne, Paula J; Stebbing, Paul D

    Watersports equipment can act as a vector for the introduction and spread of invasive non native species (INNS) in freshwater environments. To support advice given to recreational water users under the UK Government's Check Clean Dry biosecurity campaign and ensure its effectiveness at killing a range of aquatic INNS, we conducted a survival experiment on seven INNS which pose a high risk to UK freshwaters. The efficacy of exposure to hot water (45 °C, 15 min) was tested as a method by which waters users could 'clean' their equipment and was compared to drying and a control group (no treatment). Hot water had caused 99 % mortality across all species 1 h after treatment and was more effective than drying at all time points (1 h: χ2 = 117.24, p hot water or drying, 6/7 of these species survived for 16 days, highlighting the importance of good biosecurity practice to reduce the risk of accidental spread. In an additional experiment the minimum lethal temperature and exposure time in hot water to cause 100 % mortality in American signal crayfish (Pacifastacus leniusculus), was determined to be 5 min at 40 °C. Hot water provides a simple, rapid and effective method to clean equipment. We recommend that it is advocated in future biosecurity awareness campaigns.

  6. Solar heating and hot water system installed at Southeast of Saline, Unified School District 306, Mentor, Kansas

    Science.gov (United States)

    1979-01-01

    The solar system, installed in a new building, was designed to provide 52 percent of the estimated annual space heating load and 84 percent of the estimated annual potable hot water requirement. The liquid flat plate collectors are ground-mounted and cover a total area of 5125 square feet. The system will provide supplemental heat for the school's closed-loop water-to-air heat pump system and domestic hot water. The storage medium is water inside steel tanks with a capacity of 11,828 gallons for space heating and 1,600 gallons for domestic hot water. The solar heating facility is described and drawings are presented of the completed system which was declared operational in September 1978, and has functioned successfully since.

  7. Comparative Analysis of Milled Wood Lignins (MWLs Isolated from Sugar Maple (SM and Hot-Water Extracted Sugar Maple (ESM

    Directory of Open Access Journals (Sweden)

    Mangesh J. Goundalkar

    2014-03-01

    Full Text Available To further elucidate the advantageous effects of hot-water extraction (HWE on delignification, milled wood lignin (MWL was isolated from sugar maple (SM and from hot-water extracted sugar maple (ESM. Ball-milled wood was analyzed for particle size distribution (PSD before and after dioxane:water (DW extraction. The MWL samples were analyzed by analytical and spectral methods. The results indicated that the MWL isolated from SM and ESM was mainly released from the middle lamella (ML and the secondary wall (SW, respectively. The cleavage of dibenzodioxocin (DB and spirodienone (SD lignin substructures during HWE is suggested. The removal of lignin during acetone:water (AW extraction of hot-water extracted wood indicates that including an additional operation in a hardwood HWE-based biorefinery would be beneficial for processing of wood.

  8. The effect of temperature and methanol–water mixture on pressurized hot water extraction (PHWE) of anti-HIV analogoues from Bidens pilosa

    CSIR Research Space (South Africa)

    Gbashi, S

    2016-06-01

    Full Text Available Pressurized hot water extraction (PHWE) technique has recently gain much attention for the extraction of biologically active compounds from plant tissues for analytical purposes, due to the limited use of organic solvents, its cost...

  9. Measured electric hot water standby and demand loads from Pacific Northwest homes. End-Use Load and Consumer Assessment Program

    Energy Technology Data Exchange (ETDEWEB)

    Pratt, R.G.; Ross, B.A.

    1991-11-01

    The Bonneville Power Administration began the End-Use Load and Consumer Assessment Program (ELCAP) in 1983 to obtain metered hourly end-use consumption data for a large sample of new and existing residential and commercial buildings in the Pacific Northwest. Loads and load shapes from the first 3 years of data fro each of several ELCAP residential studies representing various segments of the housing population have been summarized by Pratt et al. The analysis reported here uses the ELCAP data to investigate in much greater detail the relationship of key occupant and tank characteristics to the consumption of electricity for water heating. The hourly data collected provides opportunities to understand electricity consumption for heating water and to examine assumptions about water heating that are critical to load forecasting and conservation resource assessments. Specific objectives of this analysis are to: (A) determine the current baseline for standby heat losses by determining the standby heat loss of each hot water tank in the sample, (B) examine key assumptions affecting standby heat losses such as hot water temperatures and tank sizes and locations, (C) estimate, where possible, impacts on standby heat losses by conservation measures such as insulating tank wraps, pipe wraps, anticonvection valves or traps, and insulating bottom boards, (D) estimate the EF-factors used by the federal efficiency standards and the nominal R-values of the tanks in the sample, (E) develop estimates of demand for hot water for each home in the sample by subtracting the standby load from the total hot water load, (F) examine the relationship between the ages and number of occupants and the hot water demand, (G) place the standby and demand components of water heating electricity consumption in perspective with the total hot water load and load shape.

  10. Side-by-Side Testing of Water Heating Systems: Results from the 2013-2014 Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Colon, Carlos [Florida Solar Energy Center, Cocoa, FL (United States). Bulding America Partnership for Improved Residential Construction

    2017-07-12

    The Florida Solar Energy Center (FSEC) has completed a fourth year-long evaluation on residential hot water heating systems in a laboratory environment (east central Florida, hot-humid climate). This report contains a summary of research activities regarding the evaluation of two residential electric heat pump water heaters (HPWHs), a solar thermal system utilizing a polymer glazed absorber and a high efficiency natural gas system.

  11. Thermal analysis and performance optimization of a solar hot water plant with economic evaluation

    KAUST Repository

    Kim, Youngdeuk

    2012-05-01

    The main objective of this study is to optimize the long-term performance of an existing active-indirect solar hot water plant (SHWP), which supplies hot water at 65 °C for use in a flight kitchen, using a micro genetic algorithm in conjunction with a relatively detailed model of each component in the plant and solar radiation model based on the measured data. The performance of SHWP at Changi International Airport Services (CIASs), Singapore, is studied for better payback period using the monthly average hourly diffuse and beam radiations and ambient temperature data. The data input for solar radiation model is obtained from the Singapore Meteorological Service (SMS), and these data have been compared with long-term average data of NASA (surface meteorology and solar energy or SSE). The comparison shows a good agreement between the predicted and measured hourly-averaged, horizontal global radiation. The SHWP at CIAS, which comprises 1200m 2 of evacuated-tube collectors, 50m 3 water storage tanks and a gas-fired auxiliary boiler, is first analyzed using a baseline configuration, i.e., (i) the local solar insolation input, (ii) a coolant flow rate through the headers of collector based on ASHRAE standards, (iii) a thermal load demand pattern amounting to 100m 3/day, and (iv) the augmentation of water temperature by auxiliary when the supply temperature from solar tank drops below the set point. A comparison between the baseline configuration and the measured performance of CIAS plant gives reasonably good validation of the simulation code. Optimization is further carried out for the following parameters, namely; (i) total collector area of the plant, (ii) storage volume, and (iii) three daily thermal demands. These studies are performed for both the CIAS plant and a slightly modified plant where the hot water supply to the load is adjusted constant at times when the water temperature from tank may exceed the set temperature. It is found that the latter

  12. Igniter heater EMI transient test

    Science.gov (United States)

    Cook, M.

    1989-01-01

    Testing to evaluate Redesigned Solid Rocket Motor igniter heater electromagnetic interference (EMI) effects on the Safe and Arm (S and A) device was completed. It was suspected that EMI generated by the igniter heater and it's associated electromechanical relay could cause a premature firing of the NASA Standard Initiators (NSIs) inside the S and A. The maximum voltage induced into the NSI fire lines was 1/4 of the NASA specified no-fire limit of one volt (SKB 26100066). As a result, the igniter heaters are not expected to have any adverse EMI effects on the NSIs. The results did show, however, that power switching causes occasional high transients within the igniter heater power cable. These transients could affect the sensitive equipment inside the forward skirt. It is therefore recommended that the electromechanical igniter heater relays be replaced with zero crossing solid state relays. If the solid state relays are installed, it is also recommended that they be tested for EMI transient effects.

  13. Uniform and non-uniform inlet temperature of a vertical hot water jet injected into a rectangular tank

    KAUST Repository

    El-Amin, Mohamed

    2010-12-01

    In most of real-world applications, such as the case of heat stores, inlet is not kept at a constant temperature but it may vary with time during charging process. In this paper, a vertical water jet injected into a rectangular storage tank is measured experimentally and simulated numerically. Two cases of study are considered; one is a hot water jet with uniform inlet temperature (UIT) injected into a cold water tank, and the other is a cold water jet with non-uniform inlet temperature (NUIT) injected into a hot water tank. Three different temperature differences and three different flow rates are studied for the hot water jet with UIT which is injected into a cold water tank. Also, three different initial temperatures with constant flow rate as well as three different flow rates with constant initial temperature are considered for the cold jet with NUIT which is injected into a hot water tank. Turbulence intensity at the inlet as well as Reynolds number for the NUIT cases are therefore functions of inlet temperature and time. Both experimental measurements and numerical calculations are carried out for the same measured flow and thermal conditions. The realizable k-ε model is used for modeling the turbulent flow. Numerical solutions are obtained for unsteady flow while pressure, velocity, temperature and turbulence distributions inside the water tank are analyzed. The simulated results are compared to the measured results, and they show a good agreement at low temperatures. © 2010 IEEE.

  14. Hot water after the Cold War: Water policy dynamics in (semi-)authoritarian states

    National Research Council Canada - National Science Library

    Peter P Mollinga

    2010-01-01

    ...? The article situates the question in the post-Cold War global water governance dynamics, argues that the state is a useful and required entry point for water policy analysis, explores the meaning of (semi...

  15. [Effect of ensilage on bioconversion of switchgrass to ethanol based on liquid hot water pretreatment].

    Science.gov (United States)

    Wu, Wentao; Ju, Meiting; Liu, Jinpeng; Liu, Boqun

    2016-04-25

    Ensilage is a traditional way of preserving fresh biomass. However, in order to apply ensilage to the ethanol biorefinery, two parameters need to be evaluated: quantity and quality changes of the biomass; and its effects on bioconversion process. To study these two aspects, switchgrass harvested on three different time points (Early, mid and late fall) were used as feedstock. The early fall harvested biomass was ensiled at 5 moisture levels ranging from 30% to 70%. Silage of 40% moisture and 3 other raw switchgrass were pretreated with liquid hot water, followed by enzymatic hydrolysis as well as simultaneous saccharification and fermentation. After 21 days storage pH values of all silages decreased below 4.0 and the dry matter losses were less than 2.0%, and structural sugars contents did not change dramatically. Liquid hot water caused more hemicellulose dissolution in the silage than in unensiled switchgrass. However, ensilage also increased the risk of releasing more sugar degradation products; After enzymatic hydrolysis, silage obtained higher total glucose, xylose and galactose yields than raw materials; After simultaneous saccharification and fermentation, ethanol concentration in silage was 12.1 g/L, higher than the unensiled switchgrass (10.3 g/L, 9.7 g/L and 10.6 g/L for early, mid and late fall respectively). Our results suggest that ensilage helps increase pretreatment efficiency and sugar yield, which increases final ethanol production.

  16. Differential effect of hot water treatment on whole tubers versus cut setts of yam (Dioscorea spp.).

    Science.gov (United States)

    Coyne, Daniel L; Claudius-Cole, Abiodun O; Kenyon, Lawrence; Baimey, Hugues

    2010-04-01

    The use of thermotherapy or hot water treatment (HWT) is recommended for the management of plant-parasitic nematodes and other pathogens for a range of planting material, especially vegetatively propagated crops including yams, Dioscorea spp. The sprouting (germination) and consequent viability of yam following HWT, however, appear to be influenced by the post-treatment method of planting (whole or cut setts) and cultivar. The present study was established to evaluate the sensitivity of the most popular yam cultivars in Benin and Nigeria, West Africa, to HWT at 50-53 degrees C for 20 min. Sprouting of both setts and whole tubers of most cultivars was affected by HWT. Across experiments, 47% of HWT material, compared with 61% of non-HWT material, sprouted over 8 weeks. When cut into setts, 41% of HWT or untreated tubers sprouted, compared with 72% of whole tubers. Whole, untreated tubers had highest sprouting rates (84%), and setts following HWT had the lowest (38%). Yam planting material was also not completely free of parasitic nematodes following HWT. The reaction to HWT or cutting was highly cultivar specific. Yam cultivars vary in their sensitivity to hot water therapy. Care is therefore advised in selecting yam cultivars for HWT, especially when using cut setts.

  17. Spectroscopic analysis of hot-water- and dilute-acid-extracted hardwood and softwood chips

    Science.gov (United States)

    Lehto, Joni; Louhelainen, Jarmo; Huttunen, Marko; Alén, Raimo

    2017-09-01

    Hot-water and dilute sulfuric acid pretreatments were performed prior to chemical pulping for silver/white birch (Betula pendula/B. pubescens) and Scots pine (Pinus sylvestris) chips to determine if varying pretreatment conditions on the original wood material were detectable via attenuated total reflectance (ATR) infrared spectroscopy. Pretreatment conditions varied with respect to temperature (130 °C and 150 °C) and treatment time (from 30 min to 120 min). The effects of the pretreatments on the composition of wood chips were determined by ATR infrared spectroscopy. The spectral data were compared to those determined by common wood chemistry analyses to evaluate the suitability of ATR spectroscopy method for rapid detection of changes in the wood chemical composition caused by different pretreatment conditions. In addition to determining wood species-dependent differences in the wood chemical composition, analytical results indicated that most essential lignin- and carbohydrates-related phenomena taking place during hot-water and acidic pretreatments could be described by applying this simple spectral method requiring only a small sample amount and sample preparation. Such information included, for example, the cleavage of essential lignin bonds (i.e., mainly β-O-4 linkages in guaiacyl and syringyl lignin) and formation of newly condensed lignin structures under different pretreatment conditions. Carbohydrate analyses indicated significant removal of hemicelluloses (especially hardwood xylan) and hemicelluloses-derived acetyl groups during the pretreatments, but they also confirmed the highly resistant nature of cellulose towards mild pretreatments.

  18. Characterization of pressurized hot water extracts of grape pomace: chemical and biological antioxidant activity.

    Science.gov (United States)

    Vergara-Salinas, J R; Vergara, Mauricio; Altamirano, Claudia; Gonzalez, Álvaro; Pérez-Correa, J R

    2015-03-15

    Pressurized hot water extracts obtained at different temperatures possess different compositions and antioxidant activities and, consequently, different bioactivities. We characterized two pressurized hot water extracts from grape pomace obtained at 100°C (GPE100) and 200°C (GPE200) in terms of antioxidant activity and composition, as well as protective effect on cell growth and mitochondrial membrane potential (Δψm) in a HL-60 cell culture under oxidative conditions. GPE100 extracts were richer in polyphenols and poorer in Maillard reaction products (MRPs) than were GPE200 extracts. Moreover, hydroxymethylfurfural was detected only in GPE200. Both extracts exhibited similar protective effects on cell growth (comparable to the effect of trolox). In addition, GPE100 strongly decreased the Δψm loss, reaching values even lower than those of the control culture. This protective effect may be related to its high polyphenols content. At the highest concentration assessed, both extracts showed strong cytotoxicity, especially GPE200. This cytotoxicity could be related to their MRPs content. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. High performance in low-flow solar domestic hot water systems

    Energy Technology Data Exchange (ETDEWEB)

    Dayan, M.

    1997-12-31

    Low-flow solar hot water heating systems employ flow rates on the order of 1/5 to 1/10 of the conventional flow. Low-flow systems are of interest because the reduced flow rate allows smaller diameter tubing, which is less costly to install. Further, low-flow systems result in increased tank stratification. Lower collector inlet temperatures are achieved through stratification and the useful energy produced by the collector is increased. The disadvantage of low-flow systems is the collector heat removal factor decreases with decreasing flow rate. Many solar domestic hot water systems require an auxiliary electric source to operate a pump in order to circulate fluid through the solar collector. A photovoltaic driven pump can be used to replace the standard electrical pump. PV driven pumps provide an ideal means of controlling the flow rate, as pumps will only circulate fluid when there is sufficient radiation. Peak performance was always found to occur when the heat exchanger tank-side flow rate was approximately equal to the average load flow rate. For low collector-side flow rates, a small deviation from the optimum flow rate will dramatically effect system performance.

  20. Hot water and dilute acid pretreatment of high and low specific gravity Populus deltoides clones.

    Science.gov (United States)

    Martin, Elizabeth M; Bunnell, Kris A; Lau, Ching-Shuan; Pelkki, Matthew H; Patterson, David W; Clausen, Edgar C; Smith, James A; Carrier, Danielle Julie

    2011-02-01

    Populus sp. are hardwood feedstocks that grow in forest management areas that are logged for softwoods; however, they are also being considered as an energy-destined feedstock. The objective of this work was to determine the effect of xylose yield from dilute acid and hot water pretreatments performed in unstirred batch stainless steel reactors at temperatures ranging from 140 to 200°C. Populus deltoides clones S13C20 and S7C15 used in this study originated from Eastern Texas and were cultivated for 14 years in Pine Tree, AR. P. deltoides clones S13C20 and S7C15 had specific gravities of 0.48 and 0.40, respectively. Bark and wood were examined separately. As expected, hot water pretreatments, in the tested temperature range, resulted in very little direct xylose recovery. However, the 140°C dilute acid pretreatment of the lower specific gravity clone, S7C15, wood yielded the highest average xylose recovery of 56%. This condition also yielded the highest concentration of furfural, 9 mg/g sample, which can be inhibitory to the fermentation step. The highest xylose recovery from bark samples, 31%, was obtained with clone S7C15, using the 160°C dilute acid pretreatment for 60 min.