Using of Aerogel to Improve Thermal Insulating Properties of Windows

Science.gov (United States)

Valachova, Denisa; Zdrazilova, Nada; Panovec, Vladan; Skotnicova, Iveta

2018-06-01

For the best possible thermal-technical properties of building structures it is necessary to use materials with very low thermal conductivity. Due to the increasing thermal-technical requirements for building structures, the insulating materials are developed. One of the modern thermal insulating materials is so-called aerogel. Unfortunately, this material is not used in the field of external thermal insulation composite systems because of its price and its properties. The aim of this paper is to present possibilities of using this insulating material in the civil engineering - specifically a usage of aerogel in the production of windows.

Vulcanization Kinetics and Mechanical Properties of Ethylene Propylene Diene Monomer Thermal Insulation

Directory of Open Access Journals (Sweden)

Mohamad Irfan Fathurrohman

2015-07-01

Full Text Available The vulcanization kinetics of Ethylene-propylene diene monomer (EPDM rubber thermal insulation was studied by using rheometer under isothermal condition at different temperatures. The rheometry analysis was used to determining the cure kinetic parameters and predicting the cure time of EPDM thermal insulation. The experimental results revealed that the curing curves of EPDM thermal insulation were marching and the optimum curing time decreased with increasing the temperature. The kinetic parameters were determined from the autocatalytic model showed close fitting with the experimental results, indicating suitability of autocatalytic model in characterizing the cure kinetics. The activation energy was determined from the autocatalytic model is 46.3661 kJ mol-1. The cure time were predicted from autocatalytic model and the obtained kinetic parameter by using the relationship among degree of conversion, cure temperature, and cure time. The predictions of cure time provide information for the actual curing characteristic of EPDM thermal insulation. The mechanical properties of EPDM thermal insulation with different vulcanization temperatures showed the same hardness, tensile strength and modulus at 300%, except at temperature 70 °C, while the elongation at breaking point decreased with increasing temperature of vulcanization. © 2015 BCREC UNDIP. All rights reservedReceived: 8th April 2014; Revised: 7th January 2015; Accepted: 16th January 2015How to Cite: Fathurrohman, M.I., Maspanger, D.R., Sutrisno, S. (2015. Vulcanization Kinetics and Mechanical Properties of Ethylene Propylene Diene Monomer Thermal Insulation. Bulletin of Chemi-cal Reaction Engineering & Catalysis, 10 (2, 104-110. (doi:10.9767/bcrec.10.2.6682.104-110Permalink/DOI: http://dx.doi.org/10.9767/bcrec.10.2.6682.104-110 

Multi-criteria thermal evaluation of wall enclosures of high-rise buildings insulated products based on modified fibers

Science.gov (United States)

Pavlov, Alexey; Pavlova, Larisa; Pavlova, Lyudmila

2018-03-01

In article results of research of versions of offered types of heaters on the basis of products from the modified fibers for designing energy efficient building enclosures residential high-rise buildings are presented. Traditional building materials (reinforced concrete, brick, wood) are not able to provide the required value of thermal resistance in areas with a temperate and harsh Russia climate in a single-layered enclosing structure. It can be achieved in a multi-layered enclosing structure, where the decisive role is played by new insulating materials with high thermal properties. In general, modern design solutions for external walls are based on the use of new effective thermal insulation materials with the use of the latest technology. The relevance of the proposed topic is to research thermoinsulation properties of new mineral heaters. Theoretical researches of offered heaters from mineral wool on slime-colloidal binder, bentocolloid and microdispersed binders are carried out. In addition, theoretical studies were carried out with several types of facade systems. Comprehensive studies were conducted on the resistance to heat transfer, resistance to vapor permeation and air permeability. According to the received data, recommendations on the use of insulation types depending on the number of storeys of buildings are proposed.

Environmental safety providing during heat insulation works and using thermal insulation materials

Directory of Open Access Journals (Sweden)

Velichko Evgeny

2017-01-01

Full Text Available This article considers the negative effect of thermal insulating materials and products on human health and environment pollution, particularly in terms of the composition of environmentally hazardous construction products. The authors have analyzed the complex measures for providing ecological safety, sanitary and epidemiological requirements, rules and regulations both during thermal insulation works and throughout the following operation of buildings and premises. The article suggests the protective and preventive measures to reduce and eliminate the negative impact of the proceeding of thermal insulation works on the natural environment and on human health.

Thermal insulating system particularly adapted for building construction

International Nuclear Information System (INIS)

Dyar, H.G.

1985-01-01

This disclosure relates to an insulating system which is particularly adapted for insulating the walls, floors, ceilings and like structure of buildings and includes a panel having a hollow chamber or interior under negative pressure (vacuum) and being of a variety of external peripheral sizes and shapes to fit within areas defined by wall and/or floor and/or ceiling studs, beams, or the like, a plurality of springs, chains or the like for supporting the panel in generally spaced relationship to an associated building wall, ceiling, floor or like structure, and a plurality of pin-like elements of relatively small cross-sectional configuration normally spaced from the exterior surface of the panel for contacting a limited exterior surface area of the panel only upon the springs, chains or the like becoming inoperative which would in the absence of the pin-like elements result in direct contact between the panel and the associated building wall, ceiling, floor or like structure and thus reduce the insulating efficiency thereof

Vacuum insulation panels for building applications: A review and beyond

Energy Technology Data Exchange (ETDEWEB)

Baetens, Ruben [Department of Building Materials and Structures, SINTEF Building and Infrastructure, NO-7465 Trondheim (Norway); Department of Civil and Transport Engineering, Norwegian University of Science and Technology (NTNU), NO-7491 Trondheim (Norway); Laboratory of Building Physics, Department of Civil Engineering, Catholic University of Leuven (KUL), BE-3001 Heverlee (Belgium); Jelle, Bjoern Petter [Department of Building Materials and Structures, SINTEF Building and Infrastructure, NO-7465 Trondheim (Norway); Department of Civil and Transport Engineering, Norwegian University of Science and Technology (NTNU), NO-7491 Trondheim (Norway); Thue, Jan Vincent [Department of Civil and Transport Engineering, Norwegian University of Science and Technology (NTNU), NO-7491 Trondheim (Norway); Tenpierik, Martin J. [Faculty of Architecture, Urbanism and Building Sciences, Delft University of Technology, Julianalaan 134, 2628 BL Delft (Netherlands); Grynning, Steinar; Uvsloekk, Sivert [Department of Building Materials and Structures, SINTEF Building and Infrastructure, NO-7465 Trondheim (Norway); Gustavsen, Arild [Department of Architectural Design, History and Technology, Norwegian University of Science and Technology (NTNU), NO-7491 Trondheim (Norway)

2010-02-15

Vacuum insulation panels (VIPs) are regarded as one of the most promising high performance thermal insulation solutions on the market today. Thermal performances three to six times better than still-air are achieved by applying a vacuum to an encapsulated micro-porous material, resulting in a great potential for combining the reduction of energy consumption in buildings with slim constructions. However, thermal bridging due to the panel envelope and degradation of thermal performance through time occurs with current technology. Furthermore, VIPs cannot be cut on site and the panels are fragile towards damaging. These effects have to be taken into account for building applications as they may diminish the overall usability and thermal performance. This paper is as far as the authors know the first comprehensive review on VIPs. Properties, requirements and possibilities of foil encapsulated VIPs for building applications are studied based on available literature, emphasizing thermal bridging and degradation through time. An extension is made towards gas-filled panels and aerogels, showing that other high performance thermal insulation solutions do exist. Combining the technology of these solutions and others may lead to a new leap forward. Feasible paths beyond VIPs are investigated and possibilities such as vacuum insulation materials (VIMs) and nano insulation materials (NIMs) are proposed. (author)

High performance thermal insulation systems (HiPTI). Vacuum insulated products (VIP). Proceedings of the international conference and workshop

Energy Technology Data Exchange (ETDEWEB)

Zimmermann, M.; Bertschinger, H.

2001-07-01

These are the proceedings of the International Conference and Workshop held at EMPA Duebendorf, Switzerland, in January 2001. The papers presented at the conference's first day included contributions on the role of high-performance insulation in energy efficiency - providing an overview of available technologies and reviewing physical aspects of heat transfer and the development of thermal insulation as well as the state of the art of glazing technologies such as high-performance and vacuum glazing. Also, vacuum-insulated products (VIP) with fumed silica, applications of VIP systems in technical building systems, nanogels, VIP packaging materials and technologies, measurement of physical properties, VIP for advanced retrofit solutions for buildings and existing and future applications for advanced low energy building are discussed. Finally, research and development concerning VIP for buildings are reported on. The workshops held on the second day covered a preliminary study on high-performance thermal insulation materials with gastight porosity, flexible pipes with high performance thermal insulation, evaluation of modern insulation systems by simulation methods as well as the development of vacuum insulation panels with a stainless steel envelope.

Optimization of thermal insulation to achieve energy savings in low energy house (refurbishment)

International Nuclear Information System (INIS)

Bojić, Milorad; Miletić, Marko; Bojić, Ljubiša

2014-01-01

Highlights: • For buildings that require heating, a thickness of their thermal insulation is optimized. • The objective was to improve energy efficiency of the building. • The optimization is performed by using EnergyPlus and Hooke–Jeeves method. • The embodied energy of thermal insulation and the entire life cycle of the house are taken into account. - Abstract: Due to the current environmental situation, saving energy and reducing CO 2 emission have become the leading drive in modern research. For buildings that require heating, one of the solutions is to optimize a thickness of their thermal insulation and thus improve energy efficiency and reduce energy needs. In this paper, for a small residential house in Serbia, an optimization in the thickness of its thermal insulation layer is investigated by using EnergyPlus software and Hooke–Jeeves direct search method. The embodied energy of thermal insulation is taken into account. The optimization is done for the entire life cycle of thermal insulation. The results show the optimal thickness of thermal insulation that yields the minimum primary energy consumption

Tubular House - Form Follows Technology, Concrete Shell Structure with Inner Thermal Insulation

Science.gov (United States)

Idem, Robert; Kleczek, Paweł; Pawłowski, Krzysztof; Chudoba, Piotr

2017-10-01

The aim of this paper is the theoretical analysis of the possibilities and limitations of using an unconventional technology and the original architectural form stemming from it - the building with external construction and internal insulation. In Central European climatic conditions, the traditional solution for the walls of heated buildings relies on using external thermal insulation. This stems from building physics: it prevents interstitial condensation of water vapour in the wall. Internal insulation is used exceptionally. This is done e.g. in historical buildings undergoing thermal modernization (due to the impossibility of interfering with facade). In such cases, a thermal insulation layer is used on the internal wall surface, along with an additional layer of vapour barrier. The concept of building concerns the intentional usage of an internal insulation. In this case, the construction is a tight external reinforced concrete shell. The architectural form of such building is strongly interrelated with the technology, which was used to build it. The paper presents the essence of this concept in descriptive and drawing form. The basic elements of such building are described (the external construction, the internal insulation and ventilation). As a case study, authors present a project of a residential building along with the description of the applied materials and installation solutions, and the results obtained from thermal, humidity and energetic calculations. The discussion presents the advantages and disadvantages of the proposed concept. The basic advantage of this solution is potentially low building cost. This stems from minimizing the ground works, the simplicity of the joints and the outer finish, as well as from the possibility of prefabrication of the elements. The continuity of the thermal insulation allows to reduce the amount of thermal bridges. The applied technology and form are applicable most of all for small buildings, due to limited

Thermal insulation of buildings classified as historical monuments with particular emphasis on moisture protection; Hygrisch motivierter Waermeschutz von Altbauten mit denkmalgeschuetzter Fassade

Energy Technology Data Exchange (ETDEWEB)

Haeupl, P.; Martin, R.; Fechner, H.; Neue, J. [Technische Univ. Dresden (Germany). Inst. fuer Bauklimatik

1997-12-31

Buildings classified as historical must not be fitted with external thermal insulation elements. This project investigates a `gentle` type of an internal thermal insulation system with capillary activity permitting diffusion. A 120-year-old building with a historical house-front was thermally insulated at the inside using a 30-millimetre-thick calcium silicate plate with embedded fibres having capillary activity. The paper discusses the heat flow densities between the internal thermal insulation and the original part of the structure. Moisture fields in the wall in the case of mineral wool insulation and internal thermal insulation with capillary activity are compared. Moisture distribution in the area of the juncture between masonry and window and in the area of the beam head is shown by means of diagrams. (MSK) [Deutsch] Weil bei denkmalgeschuetzten Fassanden ein aussen angebrachtes Thermoverbundsystem nicht moeglich ist, wird in diesem Projekt eine sanfte kapillaraktive, diffusionsoffene Innendaemmung untersucht. Als Referenzobjekt wurde ein etwa 120 Jahre altes Gruenderzeithaus mit denkmalgeschuetzter Fassade mit einer 30mm dicken faserdotierten kapillaraktiven Calciumsilikatplatte innenseitig gedaemmt. Im Folgenden werden die Waermestromdichten zwischen Innendaemmung und Altkonstruktion erlaeutert. Die Feuchtefelder in der Wand bei Mineralwolleindaemmung und bei kapillaraktiver Innendaemmung werden verglichen. Die Feuchteverteilung im Bereich des Fenteranschlusses und des Balkenkopfes wird in Diagrammen dargestellt.

Competitive landscape of the EU’s insulation materials industry for energy-efficient buildings

OpenAIRE

PAVEL CLAUDIU; BLAGOEVA DARINA

2017-01-01

Insulation materials could contribute significantly to improving the overall energy efficiency and sustainability of the buildings, especially by reducing the energy losses through the building envelope (walls, roofs, floors, etc.). The global demand for thermal insulation materials in building applications is projected to increase at a CAGR of 4.5 % between 2016 and 2027. In the EU the demand for thermal insulation materials is estimated at 3.48 % (2015-2027). Wool minerals (glass and stone ...

Evaluation of mechanical and thermal properties of insulation materials for HTS power devices at liquid nitrogen temperature

Energy Technology Data Exchange (ETDEWEB)

Shin, Hyung Seop; Diaz, Mark Angelo [Dept. of Mechanical Design Engineering, Andong National University, Andong (Korea, Republic of)

2017-06-15

In superconducting power devices including power cables in which high temperature superconducting (HTS) tapes are utilized, a reliable electrical insulation should be achieved for its maximum performance. For an efficient design of HTS superconducting devices, a comparative evaluation of the mechanical and thermal propperties for various insulation materials at cryogenic temperatures is required. Especially, in the process of the property evaluation of the sheet-shaped insulation materials, anisotropy according to the machining direction should be considered because the mechanical and thermal properties are significantly influenced by the sample orientation. In this study, the cryogenic thermal and mechanical properties of various insulation material sheets such as PPLP, Cryoflex, Teflon, and Kapton were determined considering sample orientation. All samples tested at cryogenic temperature showed significantly higher tensile strength as compared with that of room temperature. The ultimate tensile strength at both temperature conditions significantly depended upon the sample orientation. The thermal properties of the insulation materials exhibited a slight difference among samples depending on the orientation: for the PPLP and Cryoflex, the CD orientation showed larger thermal contraction up to 77 K as compared to the MD one. MD samples in PPLP and Cryoflex showed a lower CTE and thermal contraction which made it more promising as an insulation material due to its comparable CTE with HTS CC tapes.

Growing and testing mycelium bricks as building insulation materials

Science.gov (United States)

Xing, Yangang; Brewer, Matthew; El-Gharabawy, Hoda; Griffith, Gareth; Jones, Phil

2018-02-01

In order to improve energy performance of buildings, insulation materials (such as mineral glass and rock wools, or fossil fuel-based plastic foams) are being used in increasing quantities, which may lead to potential problem with materials depletions and landfill disposal. One sustainable solution suggested is the use of bio-based, biodegradable materials. A number of attempts have been made to develop biomaterials, such as sheep wood, hemcrete or recycled papers. In this paper, a novel type of bio insulation materials - mycelium is examined. The aim is to produce mycelium materials that could be used as insulations. The bio-based material was required to have properties that matched existing alternatives, such as expanded polystyrene, in terms of physical and mechanical characteristics but with an enhanced level of biodegradability. The testing data showed mycelium bricks exhibited good thermal performance. Future work is planned to improve growing process and thermal performance of the mycelium bricks.

Handleable shapes of thermal insulation material

Energy Technology Data Exchange (ETDEWEB)

Hughes, J. T.

1989-01-17

Handleable and machineable shapes of thermal insulation material are made by compacting finely divided thermal insulation material into the cells of a reinforcing honeycomb insulation material into the cells of a reinforcing honeycomb structure. The finely divided thermal insulation material may be, for example, silica aerogel, pyrogenic silica, carbon black, silica gel, volatilised silica, calcium silicate, vermiculate or perlite, or finely divided metal oxides such as alumina or titania. The finely divided thermal insulation material may include an infra-red opacifier and/or reinforcing fibres. The reinforcing honeycomb structure may be made from, for example, metals such as aluminium foil, inorganic materials such as ceramics, organic materials such as plastics materials, woven fabrics or paper. A rigidiser may be employed. The shapes of thermal insulation material are substantially rigid and may be machines, for example by mechanical or laser cutting devices, or may be formed, for example by rolling, into curved or other shaped materials. 12 figs.

Effect of thermal-treatment sequence on sound absorbing and mechanical properties of porous sound-absorbing/thermal-insulating composites

Directory of Open Access Journals (Sweden)

Huang Chen-Hung

2016-01-01

Full Text Available Due to recent rapid commercial and industrial development, mechanical equipment is supplemented massively in the factory and thus mechanical operation causes noise which distresses living at home. In livelihood, neighborhood, transportation equipment, jobsite construction noises impact on quality of life not only factory noise. This study aims to preparation technique and property evaluation of porous sound-absorbing/thermal-insulating composites. Hollow three-dimensional crimp PET fibers blended with low-melting PET fibers were fabricated into hollow PET/low-melting PET nonwoven after opening, blending, carding, lapping and needle-bonding process. Then, hollow PET/low-melting PET nonwovens were laminated into sound-absorbing/thermal-insulating composites by changing sequence of needle-bonding and thermal-treatment. The optimal thermal-treated sequence was found by tensile strength, tearing strength, sound-absorbing coefficient and thermal conductivity coefficient tests of porous composites.

Thermal insulation

International Nuclear Information System (INIS)

Aspden, G.J.; Howard, R.S.

1988-01-01

The patent concerns high temperature thermal insulation of large vessels, such as the primary vessel of a liquid metal cooled nuclear reactor. The thermal insulation consists of multilayered thermal insulation modules, and each module comprises a number of metal sheet layers sandwiched between a back and front plate. The layers are linked together by straps and clips to control the thickness of the module. (U.K.)

Energy savings due to building insulation of different thickness

Directory of Open Access Journals (Sweden)

Orzechowski Tadeusz

2017-01-01

Full Text Available In the plans of thermo-modernisation of historic buildings, strict requirements on energy performance are often relaxed. Detailed analyses are performed to select thermal upgrading technology that would ensure maximum environmental benefits while preserving the historic value of the building. The analysis of the costs of thermal upgrading with the use of heat-preserving plasters having different insulation properties is made for a coal-fired boiler plant. Optimal and advantageous ranges of insulation materials application are shown in reference to coal savings in boilers with variable and constant efficiency. Climatic conditions and environmental benefits are indicated.

Foam/Aerogel Composite Materials for Thermal and Acoustic Insulation and Cryogen Storage

Science.gov (United States)

Williams, Martha K. (Inventor); Smith, Trent M. (Inventor); Fesmire, James E. (Inventor); Weiser, Erik S. (Inventor); Sass, Jared P. (Inventor)

2011-01-01

The invention involves composite materials containing a polymer foam and an aerogel. The composite materials have improved thermal insulation ability, good acoustic insulation, and excellent physical mechanical properties. The composite materials can be used, for instance, for heat and acoustic insulation on aircraft, spacecraft, and maritime ships in place of currently used foam panels and other foam products. The materials of the invention can also be used in building construction with their combination of light weight, strength, elasticity, ability to be formed into desired shapes, and superior thermal and acoustic insulation power. The materials have also been found to have utility for storage of cryogens. A cryogenic liquid or gas, such as N.sub.2 or H.sub.2, adsorbs to the surfaces in aerogel particles. Thus, another embodiment of the invention provides a storage vessel for a cryogen.

Thermal Insulating Concrete Wall Panel Design for Sustainable Built Environment

Science.gov (United States)

Zhou, Ao; Wong, Kwun-Wah

2014-01-01

Air-conditioning system plays a significant role in providing users a thermally comfortable indoor environment, which is a necessity in modern buildings. In order to save the vast energy consumed by air-conditioning system, the building envelopes in envelope-load dominated buildings should be well designed such that the unwanted heat gain and loss with environment can be minimized. In this paper, a new design of concrete wall panel that enhances thermal insulation of buildings by adding a gypsum layer inside concrete is presented. Experiments have been conducted for monitoring the temperature variation in both proposed sandwich wall panel and conventional concrete wall panel under a heat radiation source. For further understanding the thermal effect of such sandwich wall panel design from building scale, two three-story building models adopting different wall panel designs are constructed for evaluating the temperature distribution of entire buildings using finite element method. Both the experimental and simulation results have shown that the gypsum layer improves the thermal insulation performance by retarding the heat transfer across the building envelopes. PMID:25177718

Facility for endurance tests of thermal insulations

International Nuclear Information System (INIS)

Mauersberger, R.

1984-01-01

In the following report the design and construction of an experimental facility for endurance tests of thermal insulations is presented. It's name in abbreviation is 'ADI' standing for the German words A nlage zum Dauertest von Isolierungen . This test facility was build by HRB in order to investigate the performance of thermal insulation systems of hot gas ducts for the process heat-reactor-project. The tests are intended to simulate the conditions of reactor operation. They include short-time experiments for selection of insulation-concepts and in a second step long-time experiments as performance tests. During these tests are measured the effective heat conductivity the local heat losses the temperature profiles of the insulation, of the fixing elements and along the wall of the duct. The design-data required to perform all these tasks are shown in the first picture: The gas-atmosphere must be Helium in tests like in reactor with regard to the special thermal and hydraulic properties of Helium and to the influence of Helium on mechanic friction and wear. The hot gas temperature in the PNP-reactor will be 950 deg. C and should be equal in the experiments. The temperature on the cold side of the insulation has to be adjustable from 50 deg. C up to 300 deg. C. The Helium pressure in the hot gas ducts of a HTR-plant is about 42 bar. The ADI was laid out for 70 bar to cover the hole range of interest. A Helium mass flow has to stream through the insulated test duct in order to realize equal temperatures on the hot side of the insulation. A flow rate of 4,5 kg/s is sufficient for this requirement. The axial pressure gradient along the insulation must be the same as in the reactor, because this has an essential influence on the heat losses. This pressure gradient is about 40 Pa/m

Simulation of energy- efficient building prototype using different insulating materials

Science.gov (United States)

Ouhaibi, Salma; Belouaggadia, Naoual; Lbibb, Rachid; Ezzine, Mohammed

2018-05-01

The objective of this work is to analyze the energetic efficiency of an individual building including an area of 130 m2 multi-zone, located in the region of FEZ which is characterized by a very hot and dry climate in summer and a quite cold one in winter, by incorporating insulating materials. This study was performed using TRNSYS V16 simulation software during a typical year of the FEZ region. Our simulation consists in developing a comparative study of two types of polystyrene and silica-aerogel insulation materials, in order to determine the best thermal performance. The results show that the thermal insulation of the building envelope is among the most effective solutions that give a significant reduction in energy requirements. Similarly, the use of silica-aerogels gives a good thermal performance, and therefore a good energy gain.

Layered Thermal Insulation Systems for Industrial and Commercial Applications

Science.gov (United States)

Fesmire, James E.

2015-01-01

From the high performance arena of cryogenic equipment, several different layered thermal insulation systems have been developed for industrial and commercial applications. In addition to the proven areas in cold-work applications for piping and tanks, the new Layered Composite Insulation for Extreme Environments (LCX) has potential for broader industrial use as well as for commercial applications. The LCX technology provides a unique combination of thermal, mechanical, and weathering performance capability that is both cost-effective and enabling. Industry applications may include, for example, liquid nitrogen (LN2) systems for food processing, liquefied natural gas (LNG) systems for transportation or power, and chilled water cooling facilities. Example commercial applications may include commercial residential building construction, hot water piping, HVAC systems, refrigerated trucks, cold chain shipping containers, and a various consumer products. The LCX system is highly tailorable to the end-use application and can be pre-fabricated or field assembled as needed. Product forms of LCX include rigid sheets, semi-flexible sheets, cylindrical clam-shells, removable covers, or flexible strips for wrapping. With increasing system control and reliability requirements as well as demands for higher energy efficiencies, thermal insulation in harsh environments is a growing challenge. The LCX technology grew out of solving problems in the insulation of mechanically complex cryogenic systems that must operate in outdoor, humid conditions. Insulation for cold work includes equipment for everything from liquid helium to chilled water. And in the middle are systems for LNG, LN2, liquid oxygen (LO2), liquid hydrogen (LH2) that must operate in the ambient environment. Different LCX systems have been demonstrated for sub-ambient conditions but are capable of moderately high temperature applications as well.

Effect of thermal insulation on the electrical characteristics of NbOx threshold switches

Science.gov (United States)

Wang, Ziwen; Kumar, Suhas; Wong, H.-S. Philip; Nishi, Yoshio

2018-02-01

Threshold switches based on niobium oxide (NbOx) are promising candidates as bidirectional selector devices in crossbar memory arrays and building blocks for neuromorphic computing. Here, it is experimentally demonstrated that the electrical characteristics of NbOx threshold switches can be tuned by engineering the thermal insulation. Increasing the thermal insulation by ˜10× is shown to produce ˜7× reduction in threshold current and ˜45% reduction in threshold voltage. The reduced threshold voltage leads to ˜5× reduction in half-selection leakage, which highlights the effectiveness of reducing half-selection leakage of NbOx selectors by engineering the thermal insulation. A thermal feedback model based on Poole-Frenkel conduction in NbOx can explain the experimental results very well, which also serves as a piece of strong evidence supporting the validity of the Poole-Frenkel based mechanism in NbOx threshold switches.

Thermal insulation properties of walls

Directory of Open Access Journals (Sweden)

Zhukov Aleksey Dmitrievich

2014-05-01

Full Text Available Heat-protective qualities of building structures are determined by the qualities of the used materials, adequate design solutions and construction and installation work of high quality. This rule refers both to the structures made of materials similar in their structure and nature and mixed, combined by a construction system. The necessity to ecaluate thermal conductivity is important for a product and for a construction. Methods for evaluating the thermal protection of walls are based on the methods of calculation, on full-scale tests in a laboratory or on objects. At the same time there is a reason to believe that even deep and detailed calculation may cause deviation of the values from real data. Using finite difference method can improve accuracy of the results, but it doesn’t solve all problems. The article discusses new approaches to evaluating thermal insulation properties of walls. The authors propose technique of accurate measurement of thermal insulation properties in single blocks and fragments of walls and structures.

An experimental study on thermal properties of composite insulation

Energy Technology Data Exchange (ETDEWEB)

Choi, Gyoung-Seok [Building and Urban Research Department, Korea Institute of Construction Technology, 2311 Daehwa-Dong, Ilsanseo-Gu, Goyang-Si, Gyeonggi-Do 411-712 (Korea); College of Architecture, Hanyang University, 17, Hangdang-Dong, Sungdong-Gu, Seoul 133-791 (Korea); Kang, Jae-Sik; Jeong, Young-Sun; Lee, Seung-Eon [Building and Urban Research Department, Korea Institute of Construction Technology, 2311 Daehwa-Dong, Ilsanseo-Gu, Goyang-Si, Gyeonggi-Do 411-712 (Korea); Sohn, Jang-Yeul [College of Architecture, Hanyang University, 17, Hangdang-Dong, Sungdong-Gu, Seoul 133-791 (Korea)

2007-04-01

In accordance with the insulation standards reinforced since 2001 and the compulsory standards on floor impact sound insulation that have been enforced since 2004, insulation materials for actual buildings have been converted to composite materials and new insulation materials have been released in the market. However, Korea is lagging behind the world in fundamental experimental studies and resources. In case of some composite insulation materials, there also have been problems of distorted performance occurring as a result of tests being conducted without having verification and evaluation on the accuracy and inaccuracy of such tests. Therefore, this study grasped the thermal properties of composite insulation materials using thermal conductivity test equipment by heat flux method, and performed quantitative evaluation on the measurement precision and uncertainty of composite materials. (author)

Thermal insulation

International Nuclear Information System (INIS)

Pinsky, G.P.

1977-01-01

Thermal insulation for vessels and piping within the reactor containment area of nuclear power plants is disclosed. The thermal insulation of this invention can be readily removed and replaced from the vessels and piping for inservice inspection, can withstand repeated wettings and dryings, and can resist high temperatures for long periods of time. 4 claims, 3 figures

Thermal insulation performance of green roof systems

Energy Technology Data Exchange (ETDEWEB)

Celik, Serdar; Morgan, Susan; Retzlaff, William; Once, Orcun [southern Illinois University (United States)], e-mail: scelik@siue.edu, e-mail: smorgan@siue.edu, e-mail: wretzla@siue.edu, e-mail: oonce@siue.edu

2011-07-01

With the increasing costs of energy, good building insulation has become increasingly important. Among existing insulation techniques is the green roof system, which consists of covering the roof of a building envelop with plants. The aim of this paper is to assess the impact of vegetation type and growth media on the thermal performance of green roof systems. Twelve different green roof samples were made with 4 different growth media and 3 sedum types. Temperature at the sample base was recorded every 15 minutes for 3 years; the insulation behavior was then analysed. Results showed that the insulation characteristics were achieved with a combination of haydite and sedum sexangulare. This study demonstrated that the choice of growth media and vegetation is important to the green roof system's performance; further research is required to better understand the interactions between growth media and plant roots.

Economically optimal thermal insulation

Energy Technology Data Exchange (ETDEWEB)

Berber, J.

1978-10-01

Exemplary calculations to show that exact adherence to the demands of the thermal insulation ordinance does not lead to an optimal solution with regard to economics. This is independent of the mode of financing. Optimal thermal insulation exceeds the values given in the thermal insulation ordinance.

Survey of thermal insulation systems

International Nuclear Information System (INIS)

Kinoshita, Izumi

1983-01-01

Better thermal insulations have been developed to meet the growing demands of industry, and studies on thermal insulation at both high temperature and low temperature have been widely performed. The purpose of this survey is to summarize data on the performances and characteristics of thermal insulation materials and thermal insulation structures (for instance, gas cooled reactors, space vehicles and LNG storage tanks), and to discuss ravious problems regarding the design of thermal insulation structures of pool-type LMFBRs. (author)

Passive Collecting of Solar Radiation Energy using Transparent Thermal Insulators, Energetic Efficiency of Transparent Thermal Insulators

Directory of Open Access Journals (Sweden)

Smajo Sulejmanovic

2014-11-01

Full Text Available This paper explains passive collection of solar radiation energy using transparent thermal insulators. Transparent thermal insulators are transparent for sunlight, at the same time those are very good thermal insulators. Transparent thermal insulators can be placed instead of standard conventional thermal insulators and additionally transparent insulators can capture solar radiation, transform it into heat and save heat just as standard insulators. Using transparent insulators would lead to reduce in usage of fossil fuels and would help protection of an environment and reduce effects of global warming, etc.

Characterization of systems for external insulation and retrofitting with emphasis on the thermal performance

DEFF Research Database (Denmark)

Rudbeck, Claus; Rose, Jørgen

1999-01-01

During the last decade retrofitting of buildings has received increased attention not only in northern Europe but throughout the world. Retrofitting of buildings is usually performed to solve one or more of the following problems: poor indoor climate, excessive heat losses, insufficient durability...... a building designer with such a choice, key parameters for insulation systems are described in a uniform manner stating their performance with regards to aesthetics, heat transfer, moisture, durability, fire and economy. Parameters given for the total insulation capability enable the building designer...... to include the effect of thermal bridges by performing simple calculations, a task which normally requires the use of numerical models. The results show that thermal bridges in external insulation systems may decrease their thermal resistance by more than 25%.Key parameters was calculated by the use...

Carbon footprint of a reflective foil and comparison with other solutions for thermal insulation in building envelope

International Nuclear Information System (INIS)

Proietti, Stefania; Desideri, Umberto; Sdringola, Paolo; Zepparelli, Francesco

2013-01-01

Highlights: ► Environmental and energy assessment of thermal insulating materials in building envelope. ► Carbon footprint of a reflective foil, conceived and produced by an Italian company. ► Study conducted according to principles of LCA – Life Cycle Assessment. ► Identification of main impacting processes and measures for reducing emissions. ► Comparison with traditional insulating materials (EPS and rockwool). - Abstract: The present study aims at assessing environmental and energy compatibility of different solutions of thermal insulation in building envelope. In fact a good insulation results in a reduction of heating/cooling energy consumptions; on the other hand construction materials undergo production, transformation and transport processes, whose energy and resources consumptions may lead to a significant decrease of the environmental benefits. The paper presents a detailed carbon footprint of a product (CFP, defined as the sum of greenhouse gas emissions and removals of a product system, expressed in CO 2 equivalents), which is a reflective foil conceived and produced by an Italian company. CFP can be seen as a Life Cycle Assessment with climate change as the single impact category; it does not assess other potential social, economic and environmental impacts arising from the provision of products. The analysis considers all stages of the life cycle, from the extraction of raw materials to the product’s disposal, i.e. “from cradle to grave”; it was carried out according to UNI EN ISO 14040 and 14044, and LCA modelling was performed using SimaPro software tool. On the basis of obtained results, different measures have been proposed in order to reduce emissions in the life cycle and neutralize residual carbon footprint. The results allowed to make an important comparison concerning the environmental performance of the reflective foil in comparison with other types of insulating materials

Thermal properties of a sandwich construction insulated with Polyurethane (DC-System)

DEFF Research Database (Denmark)

Jensen, Rasmus Lund; Dreau, Jerome Le

Rigid polyurethane foam (PUR) is a good thermal insulation product for buildings, mainly due to its low thermal conductivity (λ ≈ 20 mW/m.K), low permeability to water and stability over time. The other types of insulation products available on the market have a significantly higher thermal...... conductivity: + 50% for expanded polystyrene (λ ≈ 30 mW/m.K), + 75% for mineral wools (λ ≈ 35 mW/m.K), etc. Despite its low thermal conductivity, polyurethane foam (PUR) is not much used as insulation material for walls because of its low resistance to fire. The most common PUR boards are classified C-s2-d0...

Characterization and comparative investigation of thermally insulating layers for the turbine and engine construction

International Nuclear Information System (INIS)

Steffens, H.D.; Fischer, U.

1987-01-01

The aim of the research project was to subject commercially produced thermal insulation layer systems, the use of which seems promising for engine and turbine construction, to standardized characterisation, testing and comparison. Suitable methods and procedures for this had to be developed, in order to be able to derive instructions for optimisation guidelines for the production of improved thermal insulation systems from the results of investigations. In the context of the research project, a computer-controlled thermal shock test rig was first developed, designed and built. This test rig was designed so that important test conditions, such as the heating and cooling speed could be varied reproducibly over wide ranges. Methods and procedures were worked out, which permit a comparative qualitative and quantitative characterisation of layers of thermal insulation. From metallographic investigations, the layer build-up, layer structure, porosity and crack morphology of the layers in the delivered state and after testing could be assessed and compared. X-ray fine structure investigations gave information on the type and quantity of the phases occurring in the ceramic layers. The results of thermal shock tests which were done at different temperature intervals depending on the substrate, could be correlated with the build-up of layers and supplied information on damage mechanisms and the course of failure. (orig.) With 57 figs., 16 tabs., 89 refs [de

Thermal resistances of air in cavity walls and their effect upon the thermal insulation performance

Energy Technology Data Exchange (ETDEWEB)

Bekkouche, S.M.A.; Cherier, M.K.; Hamdani, M.; Benamrane, N. [Application of Renewable Energies in Arid and Semi Arid Environments /Applied Research Unit on Renewable Energies/ EPST Development Center of Renewable Energies, URAER and B.P. 88, ZI, Gart Taam Ghardaia (Algeria); Benouaz, T. [University of Tlemcen, BP. 119, Tlemcen R.p. 13000 (Algeria); Yaiche, M.R. [Development Center of Renewable Energies, CDER and B.P 62, 16340, Route de l' Observatoire, Bouzareah, Algiers (Algeria)

2013-07-01

The optimum thickness in cavity walls in buildings is determined under steady conditions; the heat transfer has been calculated according to ISO 15099:2003. Two forms of masonry units are investigated to conclude the advantage of high thermal emissivity. The paper presents also some results from a study of the thermal insulation performance of air cavities bounded by thin reflective material layer 'eta = 0.05'. The results show that the most economical cavity configuration depends on the thermal emissivity and the insulation material used.

Thermal Insulation System for Non-Vacuum Applications Including a Multilayer Composite

Science.gov (United States)

Fesmire, James E. (Inventor)

2017-01-01

The thermal insulation system of the present invention is for non-vacuum applications and is specifically tailored to the ambient pressure environment with any level of humidity or moisture. The thermal insulation system includes a multilayered composite including i) at least one thermal insulation layer and at least one compressible barrier layer provided as alternating, successive layers, and ii) at least one reflective film provided on at least one surface of the thermal insulation layer and/or said compressible barrier layer. The different layers and materials and their combinations are designed to provide low effective thermal conductivity for the system by managing all modes of heat transfer. The thermal insulation system includes an optional outer casing surrounding the multilayered composite. The thermal insulation system is particularly suited for use in any sub-ambient temperature environment where moisture or its adverse effects are a concern. The thermal insulation system provides physical resilience against damaging mechanical effects including compression, flexure, impact, vibration, and thermal expansion/contraction.

Improved Thermal-Insulation Systems for Low Temperatures

Science.gov (United States)

Fesmire, James E.; Augustynowicz, Stanislaw D.

2003-01-01

Improved thermal-insulation materials and structures and the techniques for manufacturing them are undergoing development for use in low-temperature applications. Examples of low-temperature equipment for which these thermal insulation systems could provide improved energy efficiency include storage tanks for cryogens, superconducting electric-power-transmission equipment, containers for transport of food and other perishable commodities, and cold boxes for low-temperature industrial processes. These systems could also be used to insulate piping used to transfer cryogens and other fluids, such as liquefied natural gas, refrigerants, chilled water, crude oil, or low-pressure steam. The present thermal-insulation systems are layer composites based partly on the older class of thermal-insulation systems denoted generally as multilayer insulation (MLI). A typical MLI structure includes an evacuated jacket, within which many layers of radiation shields are stacked or wrapped close together. Low-thermal-conductivity spacers are typically placed between the reflection layers to keep them from touching. MLI can work very well when a high vacuum level (less than 10(exp-4) torr) is maintained and utmost care is taken during installation, but its thermal performance deteriorates sharply as the pressure in the evacuated space rises into the soft vacuum range [pressures greater than 0.1 torr (greater than 13 Pa)]. In addition, the thermal performance of MLI is extremely sensitive to mechanical compression and edge effects and can easily decrease from one to two orders of magnitude from its ideal value even when the MLI is kept under high vacuum condition. The present thermal-insulation systems are designed to perform well under soft vacuum level, in particular the range of 1 to 10 torr. They are also designed with larger interlayer spacings to reduce vulnerability to compression (and consequent heat leak) caused by installation and use. The superiority of these systems is the

Foundation heat transfer analysis for buildings with thermal piles

International Nuclear Information System (INIS)

Almanza Huerta, Luis Enrique; Krarti, Moncef

2015-01-01

Highlights: • A numerical transient thermal model for thermo-active foundations is developed. • Thermal interactions between thermal piles and building foundations are evaluated. • A simplified analysis method of thermal interactions between thermal piles and building foundations is developed. - Abstract: Thermal piles or thermo-active foundations utilize heat exchangers embedded within foundation footings to heat and/or cool buildings. In this paper, the impact of thermal piles on building foundation heat transfer is investigated. In particular, a simplified analysis method is developed to estimate the annual ground-coupled foundation heat transfer when buildings are equipped with thermal piles. First, a numerical analysis of the thermal performance of thermo-active building foundations is developed and used to assess the interactions between thermal piles and slab-on-grade building foundations. The impact of various design parameters and operating conditions is evaluated including foundation pile depth, building slab width, foundation insulation configuration, and soil thermal properties. Based on the results of a series of parametric analyses, a simplified analysis method is presented to assess the impact of the thermal piles on the annual heat fluxes toward or from the building foundations. A comparative evaluation of the predictions of the simplified analysis method and those obtained from the detailed numerical analysis indicated good agreement with prediction accuracy lower than 5%. Moreover, it is found that thermal piles can affect annual building foundation heat loss/gain by up to 30% depending on foundation size and insulation level

Utilization of Baggase Waste Based Materials as Improvement for Thermal Insulation of Cement Brick

Directory of Open Access Journals (Sweden)

Aminudin Eeydzah

2017-01-01

Full Text Available Building materials having low thermal load and low thermal conductivity will provide thermal comforts to the occupants in building. In an effort to reduce the use of high energy and waste products from the agricultural industry, sugarcane bagasse and banana bagasse has been utilize as an additive in the manufacture of cement brick. The aim of this study is to investigate the insulation and mechanical properties of brick that has been mixed with bagasse and its effectiveness as thermal insulation using heat flow meter. Waste bagasse is being treated using sodium hydroxide (NaOH and is characterized using SEM and XRF. The samples produced with two different dimensions of 50 mm × 50 mm × 50 mm and 215mm × 102.5mm × 65mm for thermal conductivity test. Next, the sample varies from 0% (control sample, 2%, 4%, 6%, 8% and 10% in order to determine the best mix proportion. The compressive strength is being tested for 7, 14 and 28 days of water curing. Results showed that banana bagasse has lower thermal conductivity compared to sugarcane bagasse used, with compressive strength of 15.6MPa with thermal conductivity 0.6W/m.K.

Transparent thermal insulation - new developments in the field of building technology?; Transparente Waermedaemmung - neue Trends in der Gebaeudetechnik?

Energy Technology Data Exchange (ETDEWEB)

Bieler, P.

1995-12-31

In chapter 10 of the anthology about building control transparent thermal insulation is described as a possible new trend in the field of building technology. An answer is given to the question to which extent facades can be applied as technical building equipment. Furthermore the passive use of solar energy is discussed and the measuring results of a test cell building are presented. (BWI) [Deutsch] Kapitel 10 des Sammelbandes ueber Building Control stellt die transparente Waermedaemmung als moeglichen neuen Trend der Gebaeudetechnik vor. In diesem Zusammenhang wird die Frage aufgeworfen, inwieweit Fassaden als Technische Gebaeudeausruestung eingesetzt und angesehen werden koennen. Ferner werden die passive Solarenergienutzungen angesprochen und Messergebnisse eines Testzellengebaeudes vorgestellt. (BWI)

Effect of Thermal Environment on the Mechanical Behaviors of Building Marble

Directory of Open Access Journals (Sweden)

Haijian Su

2018-01-01

Full Text Available High temperature and thermal environment can influence the mechanical properties of building materials worked in the civil engineering, for example, concrete, building rock, and steel. This paper examines standard cylindrical building marble specimens (Φ50 × 100 mm that were treated with high temperatures in two different thermal environments: vacuum (VE and airiness (AE. Uniaxial compression tests were also carried out on those specimens after heat treatment to study the effect that the thermal environment has on mechanical behaviors. With an increase in temperature, the mechanical behavior of marble in this study indicates a critical temperature of 600°C. Both the peak stress and elasticity modulus were larger for the VE than they were for the AE. The thermal environment has an obvious influence on the mechanical properties, especially at temperatures of 450∼750°C. The failure mode of marble specimens under uniaxial compression is mainly affected by the thermal environment at 600°C.

A New Generation of Building Insulation by Foaming Polymer Blend Materials with CO₂

Energy Technology Data Exchange (ETDEWEB)

Yang, Arthur [Industrial Science & Technology Network, Inc., Lancaster, PA (United States); Domszy, Roman [Industrial Science & Technology Network, Inc., Lancaster, PA (United States); Yang, Jeff [Industrial Science & Technology Network, Inc., Lancaster, PA (United States)

2016-03-30

Advanced thermal insulation is among the most effective technologies in transforming our nation’s energy system and contributing to DOE’s stated goal of 50% less building energy consumption by 2030. The installation of an advanced thermal insulation would prevent energy waste without the need for any maintenance, and ISTN conservatively estimates that the commercialization of such a new technology would contribute to annual U.S. energy savings of 0.361 Quads and $8 billion in annual economic savings. The key challenge to improving building insulation is to maintain and surpass the industry standard of R-5 per inch insulation value in a cost-competitive manner. Improvements in R-value without cost-efficiency are not likely to impact the market given the cost-sensitive nature of the construction industry (insulation is already the lowest-cost component of the building envelope). However, significantly higher insulating value at competitive costs is extremely appealing to the market given the greater potential to save on energy consumption and costs over the long-term. Thus, our goal is to develop a super-thermal insulation with 50% greater insulation value (R-9 to R-10 per inch) and manufacturing costs that are equal on a per-R-value basis (< $0.70/ft²).

HiPTI - High Performance Thermal Insulation, Annex 39 to IEA/ECBCS-Implementing Agreement. Vacuum insulation in the building sector. Systems and applications

Energy Technology Data Exchange (ETDEWEB)

Binz, A.; Moosmann, A.; Steinke, G.; Schonhardt, U.; Fregnan, F. [Fachhochschule Nordwestschweiz (FHNW), Muttenz (Switzerland); Simmler, H.; Brunner, S.; Ghazi, K.; Bundi, R. [Swiss Federal Laboratories for Materials Testing and Research (EMPA), Duebendorf (Switzerland); Heinemann, U.; Schwab, H. [ZAE Bayern, Wuerzburg (Germany); Cauberg, H.; Tenpierik, M. [Delft University of Technology, Delft (Netherlands); Johannesson, G.; Thorsell, T. [Royal Institute of Technology (KTH), Stockholm (Sweden); Erb, M.; Nussbaumer, B. [Dr. Eicher und Pauli AG, Basel and Bern (Switzerland)

2005-07-01

This final report on vacuum insulation panels (VIP) presents and discusses the work done under IEA/Energy Conservation in Buildings and Community Systems (ECBCS) Annex 39, subtask B on the basis of a wide selection of reports from practice. The report shows how the building trade deals with this new material today, the experience gained and the conclusions drawn from this work. As well as presenting recommendations for the practical use of VIP, the report also addresses questions regarding the effective insulation values to be expected with current VIP, whose insulation performance is stated as being a factor of five to eight times better than conventional insulation. The introduction of this novel material in the building trade is discussed. Open questions and risks are examined. The fundamentals of vacuum insulation panels are discussed and the prerequisites, risks and optimal application of these materials in the building trade are examined.

Determination of the Thermal Insulation for the Model Building Approach and the Global Effects in Turkey

Directory of Open Access Journals (Sweden)

Cenk Onan

2014-08-01

Full Text Available One of the most important considerations to be considered in the design of energy efficient buildings is the thickness of the insulation to be applied to the building. In this study the existing building stock in Turkey has been investigated depending on parameters such as the height and the area. A model building has been created covering all of these buildings. Fuel emission reduction of combustion system was calculated in the case of insulation applied to this model building. Heat loss of the existing building stock and exhaust emissions and the contribution to the country's economy with the model building methodology are also determined. The results show that the optimum insulation thicknesses vary between 3.21 and 7.12 cm, the energy savings vary between 9.23 US$/m2 and43.95 US$/m2, and the payback periods vary between 1 and 8.8 years depending on the regions. As a result of the study when the optimum insulation thickness is applied in the model building, the total energy savings for the country are calculated to be 41.7 billion US$. And also total CO2 emissions for the country are calculated to be 57.2 billion kg CO2 per year after insulation.

The efficacy of a highly insulated building in KwaZulu-Natal

CSIR Research Space (South Africa)

Van Wyk, Llewellyn V

2013-10-01

Full Text Available The CSIR undertook an energy and thermal performance research project in 2011 on a house constructed with the Imison 3 Building System. The purpose was to analyse the energy and thermal performance of a highly insulated house in Pretoria. The scope...

The impact of thermal bridges on the energy demand of buildings with double brick wall constructions

Energy Technology Data Exchange (ETDEWEB)

Theodosiou, T.G. [Department of Engineering and Management of Energy Resources, University of Western Macedonia, GR-50100 Kozani (Greece); Papadopoulos, A.M. [Laboratory of Heat Transfer and Environmental Engineering, Department of Mechanical Engineering, Aristotle University Thessaloniki, GR-54124 Thessaloniki (Greece)

2008-07-01

The implementation of the European Directive on the Energy Performance of Buildings (EPBD) is a milestone towards the improvement of energy efficiency in the building sector. However, even in cases where impressive measures can be implemented in the densely built urban environment, the less glamorous measure of building's envelope thermal insulation remains a prerequisite towards the improvement of the building's energy efficiency. Despite the insulation requirements specified by national regulations, thermal bridges in the building's envelope remain a weak spot in the constructions. Moreover, in many countries construction practices tend to implement only partially the insulation measures foreseen by regulations. As a result, thermal losses are in practice greater than those predicted during the design stage. This paper presents a study on representative wall thermal insulation configurations used in Greek buildings, in order to investigate the impact of the thermal bridges on the energy consumption. The double wall construction, used widely in Greece and not only there, is rather susceptible to the occurrence of thermal bridges, in contrast to a typical thermal insulating facade, like the one applied in Central Europe. The analysis of the thermal bridges' impact will in that sense also highlight the potential for energy renovation measures in older buildings. (author)

Thermal insulation

International Nuclear Information System (INIS)

Durston, J.G.; Birch, W.; Facer, R.I.; Stuart, R.A.

1977-01-01

Reference is made to liquid metal cooled nuclear reactors. In the arrangement described the reactor vessel is clad with thermal insulation comprising a layer of insulating blocks spaced from the wall and from each other; each block is rigidly secured to the wall, and the interspaces are substantially closed against convectional flow of liquid by resilient closure members. A membrane covering is provided for the layer of blocks, with venting means to allow liquid from the reactor vessel to penetrate between the covering and the layer of blocks. The membrane covering may comprise a stainless steel sheet ribbed in orthogonal pattern to give flexibility for the accommodation of thermal strain. The insulating blocks may be comprised of stainless steel or cellular or porous material and may be hollow shells containing ceramic material or gas fillings. (U.K.)

Local Thermal Insulating Materials For Thermal Energy Storage ...

African Journals Online (AJOL)

Thermal insulation is one of the most important components of a thermal energy storage system. In this paper the thermal properties of selected potential local materials which can be used for high temperature insulation are presented. Thermal properties of seven different samples were measured. Samples consisted of: ...

Thermally insulating and fire-retardant lightweight anisotropic foams based on nanocellulose and graphene oxide

Science.gov (United States)

Wicklein, Bernd; Kocjan, Andraž; Salazar-Alvarez, German; Carosio, Federico; Camino, Giovanni; Antonietti, Markus; Bergström, Lennart

2015-03-01

High-performance thermally insulating materials from renewable resources are needed to improve the energy efficiency of buildings. Traditional fossil-fuel-derived insulation materials such as expanded polystyrene and polyurethane have thermal conductivities that are too high for retrofitting or for building new, surface-efficient passive houses. Tailored materials such as aerogels and vacuum insulating panels are fragile and susceptible to perforation. Here, we show that freeze-casting suspensions of cellulose nanofibres, graphene oxide and sepiolite nanorods produces super-insulating, fire-retardant and strong anisotropic foams that perform better than traditional polymer-based insulating materials. The foams are ultralight, show excellent combustion resistance and exhibit a thermal conductivity of 15 mW m-1 K-1, which is about half that of expanded polystyrene. At 30 °C and 85% relative humidity, the foams retained more than half of their initial strength. Our results show that nanoscale engineering is a promising strategy for producing foams with excellent properties using cellulose and other renewable nanosized fibrous materials.

Development of fly ash boards with thermal, acoustic and fire insulation properties.

Science.gov (United States)

Leiva, C; Arenas, C; Vilches, L F; Alonso-Fariñas, B; Rodriguez-Galán, M

2015-12-01

This paper presents an experimental analysis on a new board composed of gypsum and fly ashes from coal combustion, which are mutually compatible. Physical and mechanical properties, sound absorption coefficient, thermal properties and leaching test have been obtained. The mechanical properties showed similar values to other commercial products. As far as the acoustic insulation characteristics are concerned, sound absorption coefficients of 0.3 and 0.8 were found. The board presents a low thermal conductivity and a fire resistance higher than 50 min (for 4 cm of thickness). The leaching of trace elements was below the leaching limit values. These boards can be considered as suitable to be used in building applications as partitions. Copyright © 2015 Elsevier Ltd. All rights reserved.

Design and testing of botanical thermotropic actuator mechanisms in thermally adaptive building coverings

Science.gov (United States)

Barrett, Ronald M.; Barrett, Ronald P.; Barrett, Cassandra M.

2017-09-01

This paper lays out the inspiration, operational principles, analytical modeling and coupon testing of a new class of thermally adaptive building coverings. The fundamental driving concepts for these coverings are derived from various families of thermotropic plant structures. Certain plant cellular structures like those in Mimosa pudica (Sensitive Plant), Rhododendron leaves or Albizia julibrissin (Mimosa Tree), exhibit actuation physiology which depends on changes in cellular turgor pressures to generate motion. This form of cellular action via turgor pressure manipulation is an inspiration for a new field of thermally adaptive building coverings which use various forms of cellular foam to aid or enable actuation much like plant cells are used to move leaves. When exposed to high solar loading, the structures use the inherent actuation capability of pockets of air trapped in closed cell foam as actuators to curve plates upwards and outwards. When cold, these same structures curve back towards the building forming large convex pockets of dead air to insulate the building. This paper describes basic classical laminated plate theory models comparing theory and experiment of such coupons containing closed-cell foam actuators. The study concludes with a global description of the effectiveness of this class of thermally adaptive building coverings.

Properties of Agro-Industrial Aerated Concrete as Potential Thermal Insulation for Building

Directory of Open Access Journals (Sweden)

Aminudin Eeydzah

2016-01-01

Full Text Available The present paper is aiming to provide an actual state of the development of non autoclaved Agro-Industrial aerated concrete by using multiple ashes as improvement of thermal behavior for building. The feasibility of Agro-Industrial wastes as lightweight concrete by utilizing the Palm Oil Fuel Ash (POFA as binder replacement and bottom ash as fine aggregate was investigated in this paper. Portland cement, bottom ash, aluminum powder and lime (Ca(OH2 were used in this study. The POFA was used to replace Portland cement and Hydrated Lime at 0%, 5%, 10% and 15% by weight and aluminum powder was added at 0.75% dry weight in order to form bubbles. The compressive strength, water absorption, porosity and the thermal conductivity test were carried out after the concrete were water cured for 7 days and later being exposed to the air and water until 28days. The results show that the 20% replacements give the optimum strength of 7.143MPa and 30% give the best thermal conductivity with 0.48W/mK. Hence, this study aim, was to develop an agro-industrial aerated concrete good in insulation but having an optimum strength. Hence, it has been found that the more the percentage of POFA is added the lower the thermal conductivity since the pore structure is increasing and by the optimization done, 30% replacement has been chosen as the best mix design for Agro-Industrial Aerated Concrete.

Experimental performance evaluation of solid concrete and dry insulation materials for passive buildings in hot and humid climatic conditions

International Nuclear Information System (INIS)

Rehman, Hassam Ur

2017-01-01

Highlights: • Experimental investigation of building insulation materials in UAE from 2012–2014. • Four same calorimeters with different south walls were built in open air laboratory. • Heat flux was reduced by 22–75% in steady state analysis during summer by insulation. • Hence, energy consumption for cooling was reduced by an average 7.6–25.3%. • Heat flow was steady in free floating analysis in winter through insulated walls. - Abstract: It is known that enhancement of building energy efficiency can help in reducing energy consumption. The use of the solar insulating materials are the most efficient and cost effective passive methods for reducing the cooling requirements of the buildings. Apart from theoretical studies, no detailed experimental studies were performed in the UAE on energy savings by using solar insulation materials on buildings. Four (3 m × 3 m × 3 m) solar calorimeters were built in RAK, UAE in order to perform an open air outdoor test for energy savings obtained with solar insulating materials. The design is aimed to determine the heat flux reduction and the energy savings achieved with and without different solar insulating materials, mounted at the south wall of solar calorimeters with similar indoor and ambient conditions. Experimental results are discussed to evaluate the thermal performance during high temperature conditions in summer’s period when cooling demand of the building is at its peak and also in winters when there is no cooling demand. The test is from 2012 to 2014. The controlled-temperature experimental study at a set point of 24 °C showed that if the standard building material, i.e. solid concrete, is retrofitted with polyisocyanurate (PIR) and reflective coatings or completely replaced with energy-efficient dry insulation material walls such as exterior insulation finishing system (EIFS), energy savings up to an average of 7.6–25.3% can be achieved. This is due to the reduction of heat flux by an

Wood moisture monitoring during log house thermal insulation mounting

Directory of Open Access Journals (Sweden)

Pavla Kotásková

2011-01-01

Full Text Available The current designs of thermal insulation for buildings concentrate on the achievement of the required heat transmission coefficient. However, another factor that cannot be neglected is the assessment of the possible water vapour condensation inside the construction. The aim of the study was to find out whether the designed modification of the cladding structure of an existing log house will or will not lead to a risk of possible water vapour condensation in the walls after an additional thermal insulation mounting. The condensation could result in the increase in moisture of the walls and consequently the constructional timber, which would lead to the reduction of the timber construction strength, wood degradation by biotic factors – wood-destroying insects, mildew or wood-destroying fungi. The main task was to compare the theoretically established values of moisture of the constructional timber with the values measured inside the construction using a specific example of a thermal insulated log house. Three versions of thermal insulation were explored to find the solution of a log house reconstruction which would be the optimum for living purposes. Two versions deal with the cladding structure with the insulation from the interior, the third version deals with an external insulation.In a calculation model the results can be affected to a great degree by input values (boundary conditions. This especially concerns the factor of vapour barrier diffusion resistance, which is entered in accordance with the producer’s specifications; however, its real value can be lower as it depends on the perfectness and correctness of the technological procedure. That is why the study also includes thermal technical calculations of all designed insulation versions in the most unfavourable situation, which includes the degradation of the vapour barrier down to 10% efficiency, i.e. the reduction of the diffusion resistance factor to 10% of the original value

Lightweight, Thermally Insulating Structural Panels

Science.gov (United States)

Eisen, Howard J.; Hickey, Gregory; Wen, Liang-Chi; Layman, William E.; Rainen, Richard A.; Birur, Gajanana C.

1996-01-01

Lightweight, thermally insulating panels that also serve as structural members developed. Honeycomb-core panel filled with low-thermal-conductivity, opacified silica aerogel preventing convection and minimizes internal radiation. Copper coating on face sheets reduces radiation. Overall thermal conductivities of panels smaller than state-of-art commercial non-structurally-supporting foam and fibrous insulations. On Earth, panels suitable for use in low-air-pressure environments in which lightweight, compact, structurally supporting insulation needed; for example, aboard high-altitude aircraft or in partially evacuated panels in refrigerators.

Animal thermoregulation: a review of insulation, physiology and behaviour relevant to temperature control in buildings.

Science.gov (United States)

McCafferty, D J; Pandraud, G; Gilles, J; Fabra-Puchol, M; Henry, P-Y

2017-12-28

Birds and mammals have evolved many thermal adaptations that are relevant to the bioinspired design of temperature control systems and energy management in buildings. Similar to many buildings, endothermic animals generate internal metabolic heat, are well insulated, regulate their temperature within set limits, modify microclimate and adjust thermal exchange with their environment. We review the major components of animal thermoregulation in endothermic birds and mammals that are pertinent to building engineering, in a world where climate is changing and reduction in energy use is needed. In animals, adjustment of insulation together with physiological and behavioural responses to changing environmental conditions fine-tune spatial and temporal regulation of body temperature, while also minimizing energy expenditure. These biological adaptations are characteristically flexible, allowing animals to alter their body temperatures to hourly, daily, or annual demands for energy. They exemplify how buildings could become more thermally reactive to meteorological fluctuations, capitalising on dynamic thermal materials and system properties. Based on this synthesis, we suggest that heat transfer modelling could be used to simulate these flexible biomimetic features and assess their success in reducing energy costs while maintaining thermal comfort for given building types.

The Effect of Mechanical Load on the Thermal Conductivity of Building Materials

Directory of Open Access Journals (Sweden)

J. Toman

2000-01-01

Full Text Available The effect of mechanical load on the thermal conductivity of building materials in the design of envelope parts of building structures is studied. A typical building material is chosen in the practical investigation of this effect, namely the cement mortar. It is concluded that in the range of hygroscopic moisture content, lower levels of mechanical load, typically up to 90 % of compressive strength (CS, are not dangerous from the point of view of worsening the designed thermal properties, but in the overhygroscopic region, the load as low as 57 % of CS may be dangerous. The higher levels of loading are found to be always significant because they lead to marked increase of thermal conductivity which is always a negative information for a building designer.

Exploration of porous SiC nanostructures as thermal insulator with high thermal stability and low thermal conductivity

Institute of Scientific and Technical Information of China (English)

Peng; WAN; Jingyang; WANG

2016-01-01

The crucial challenge for current nanoscale thermal insulation materials,such as Al2O3 and SiO2 aerogel composites,is to solve the trade-off between extremely low thermal conductivity and unsatisfied thermal stability.Typical high-temperature ceramic SiC possesses excellent mechanical properties and

Thermal insulating panel

Energy Technology Data Exchange (ETDEWEB)

Hughes, J.T.

1985-09-11

A panel of thermal insulation material has at least one main portion which comprises a dry particulate insulation material compressed within a porous envelope so that it is rigid or substantially rigid and at least one auxiliary portion which is secured to and extends along at least one of the edges of the main portions. The auxiliary portions comprise a substantially uncompressed dry particulate insulation material contained within an envelope. The insulation material of the auxiliary portion may be the same as or may be different from the insulation material of the main portion. The envelope of the auxiliary portion may be made of a porous or a non-porous material. (author).

Vacuum Insulation Panels (VIPs) for building construction industry - A review of the contemporary developments and future directions

International Nuclear Information System (INIS)

Alam, M.; Singh, H.; Limbachiya, M.C.

2011-01-01

Highlights: → Vacuum Insulation Panels (VIP), a high thermal resistance building insulation. → Review of research into VIPs for building applications. → High cost and uncertainty of service life are two barriers for VIP use in buildings. → SiO 2 /SiN x coated PET laminate- candidate for high barrier VIP envelope. → The optimum combination of VIP core and envelope yet to be determined. -- Abstract: Demand for energy efficient buildings has increased drastically in recent years and this trend will continue in the future. Insulating building elements will play a key role in meeting this demand by reducing heat losses through the building fabric. Due to their higher thermal resistance, Vacuum Insulation Panels (VIPs) would be a more energy efficient alternative to conventional building insulation materials. Thus, efforts to develop VIPs with characteristics suitable for applications to new and existing buildings are underway. This paper provides a review of important contemporary developments towards producing VIPs using various materials such as glass fibre, foams, perlite and fibre/powder composites. The limitations of the materials currently used to fabricate VIPs have not been emphasised in detail in previous review papers published. Selection criteria, methods to measure important properties of VIPs and analytical and numerical models presented in the past have been detailed. Limitations of currently employed design tools along with potential future materials such as Nano/microcellular foams and SiO x /SiN x coatings for use in VIPs are also described.

Thermal-Insulation Properties of Multilayer Textile Packages

Directory of Open Access Journals (Sweden)

Matusiak Małgorzata

2014-12-01

Full Text Available Thermal-insulation properties of textile materials play a significant role in material engineering of protective clothing. Thermal-insulation properties are very important from the point of view of thermal comfort of the clothing user as well as the protective efficiency against low or high temperature. Thermal protective clothing usually is a multilayer construction. Its thermal insulation is a resultant of a number of layers and their order, as well as the thermalinsulation properties of a single textile material creating particular layers. The aim of the presented work was to investigate the relationships between the thermal-insulation properties of single materials and multilayer textile packages composed of these materials. Measurement of the thermal-insulation properties of single and multilayer textile materials has been performed with the Alambeta. The following properties have been investigated: thermal conductivity, resistance and absorptivity. Investigated textile packages were composed of two, three and four layers made of woven and knitted fabrics, as well as nonwovens. On the basis of the obtained results an analysis has been carried out in order to assess the dependency of the resultant values of the thermal-insulation properties of multilayer packages on the appropriate values of particular components.

Optimum Insulation Thickness for Walls and Roofs for Reducing Peak Cooling Loads in Residential Buildings in Lahore

Directory of Open Access Journals (Sweden)

SIBGHA SIDDIQUE SIDDIQUE

2016-10-01

Full Text Available Thermal insulation is the most effective energy saving measure for cooling in buildings. Therefore, the main subject of many engineering investigations is the selection and determination of the optimum insulation thickness. In the present study, the optimum insulation thickness on external walls and roofs is determined based on the peak cooling loads for an existing residential building in Lahore, Pakistan. Autodesk® Revit 2013 is used for the analysis of the building and determination of the peak cooling loads. The analysis shows that the optimum insulation thickness to reduce peak cooling loads up to 40.1% is 1 inch for external walls and roof respectively.

Optimum Insulation Thickness for Walls and Roofs for Reducing Peak Cooling Loads in Residential Buildings in Lahore

International Nuclear Information System (INIS)

Siddique, S.; Arif, S.; Khan, A.; Alam, A.T.

2016-01-01

Thermal insulation is the most effective energy saving measure for cooling in buildings. Therefore, the main subject of many engineering investigations is the selection and determination of the optimum insulation thickness. In the present study, the optimum insulation thickness on external walls and roofs is determined based on the peak cooling loads for an existing residential building in Lahore, Pakistan. Autodesk at the rate Revit 2013 is used for the analysis of the building and determination of the peak cooling loads. The analysis shows that the optimum insulation thickness to reduce peak cooling loads up to 40.1 percent is 1 inch for external walls and roof respectively. (author)

Parametric fuselage design : Integration of mechanics and acoustic & thermal insulation

NARCIS (Netherlands)

Krakers, L.A.

2009-01-01

Designing a fuselage is a very complex process, which involves many different aspects like strength and stability, fatigue, damage tolerance, fire resistance, thermal and acoustic insulation but also inspection, maintenance, production and repair aspects. It is difficult to include all design

Interior insulation – Experimental investigation of hygrothermal conditions and damage evaluation of solid masonry façades in a listed building

DEFF Research Database (Denmark)

Odgaard, Tommy; Bjarløv, Søren Peter; Rode, Carsten

2018-01-01

Exterior walls in historic multi-storey buildings compared to walls in modern buildings have low thermal resistance, resulting in high energy loss and cold surfaces/floors in cold climates. When restrictions regarding alteration of the exterior appearance exist, interior insulation might be the o......Exterior walls in historic multi-storey buildings compared to walls in modern buildings have low thermal resistance, resulting in high energy loss and cold surfaces/floors in cold climates. When restrictions regarding alteration of the exterior appearance exist, interior insulation might...... be the only possibility to increase occupant comfort. This paper describes an investigation of the hygrothermal influence when applying 100 mm of diffusion open interior insulation to a historic multi-storey solid masonry spandrel. The dormitory room with the insulated spandrel had a normal indoor climate...... showed no risk of damage from the changed hygrothermal conditions when applying interior insulation to a solid masonry spandrel....

Integrating a vented airspace into a spray-foam insulated solid masonry historic building in a cold climate: a case study

Energy Technology Data Exchange (ETDEWEB)

Tzekova, Ekaterina; Pressnail, K.D.; Binkley, Clarissa [Department of Civil Engineering, University of Toronto (Canada); Pearson, Nastassja [Halsall Associates Limited (Canada); Pasqualini, Paul [Engineering Link Inc (Canada); Aikin, Craig [Halcrow Yolles (Canada)

2011-07-01

Thermal insulation was not included during the construction of historic brick buildings in Canada. Although thermal retrofits can improve building energy performance and occupant comfort, heritage requirements restrict the use of internal insulation. This paper presents an innovative Vented Masonry Retrofit (VMR), which consists of creating a vented airspace by incorporating Mortairvent between the insulation and the masonry. A numerical model and a field trial involving a three-storey heritage building were performed to compare the hygrothermal performance of the VMR with that of standard interior insulation. Temperature and relative humidity were collected during the winter months in foam-insulated, side-by-side wall assemblies along the east and south facing walls using both approaches. Modeling results predicted that using VMR assemblies would reduce the moisture content in both east and south elevations to below that obtained with standard insulation. However, the field trial showed improvement only along the south facade. Long term performance evaluation is required far a better evaluation of the VMR approach.

Vacuum Insulation Panels - Study on VIP-components and panels for service life prediction of VIP in building applications (Subtask A)

Energy Technology Data Exchange (ETDEWEB)

Simmler, H.; Brunner, S. [Swiss Federal Laboratories for Materials Testing and Research (EMPA), Duebendorf (Switzerland); Heinemann, U.; Schwab, H. [Bavarian Centre for Applied Energy Research (ZAE Bayern), Garching (Germany); Kumaran, K.; Mukhopadhyaya, P. [National Research Council, Institute for Research in Construction (NRC-IRC), Ottawa (Canada); Quenard, D.; Sallee, H. [Scientific and Technical Centre for Construction (CSTB), Marne la Vallee (France); Noller, K.; Kuecuekpinar-Niarchos, E.; Stramm, C. [Fraunhofer Institute for Process Engineering and Packaging (IVV), Freising (Germany); Tenpierik, M.; Cauberg, H. [Technical University of Delft, Delft (Netherlands); Erb, M. [Dr. Eicher und Pauli AG (Switzerland)

2005-09-15

This comprehensive paper takes a look at the properties of vacuum insulation panels (VIP) and was presented as a contribution to the IEA's ECBCS (Energy Conservation in Buildings and Community Systems) Annex 39. The various institutions in Switzerland, Germany, Canada, France, Sweden and the Netherlands participating in the task and their activities are listed. The paper describes the concept of vacuum insulation for buildings and examines the physics involved and core materials that can be used. The physical, mechanical and thermal properties of the core materials are examined and the requirements placed on the envelope of the panels are looked at. Tests made on materials as well as on the complete vacuum insulation panels are described in detail. The results obtained are presented and reviewed. Service-life and quality assurance aspects are also discussed. A comprehensive appendix completes the report.

Heat-insulating mortars for older buildings. Problem solutions for all kinds of building materials. Waermedaemmputze in der Altbausanierung. Problemloesungen auf allen Untergruenden

Energy Technology Data Exchange (ETDEWEB)

Bresch, C M

1988-01-01

The book is a guideline for the renovation and sanitation of outer walls with improved thermal insulation. Heat-insulating mortars are described, and machines and equipment for efficient roughcasting are listed. Subjects: Heat-insulating mortars; protective cover and thermal insulation; surfaces to be plastered (old brick walls, house fronts, wall cracks); renovation or sanitation; colours and structures; manual and mechanized roughcasting; calculations; an exemplary case of sanitation, solutions for constructional details; light-weight mortar; heat-insulating mortars in Austria. (HWJ).

Use of XPS thermal insulator boards in design of educational spaces

African Journals Online (AJOL)

Heating and cooling equipment capacity becomes smaller than half after proper implementation of thermal insulation. As air conditioning equipment becomes small, implementation of optimization not only becomes free but also reduces the overall cost of construction. Keywords: School, modern materials, Building and ...

Modeling of Dynamic Responses in Building Insulation

Directory of Open Access Journals (Sweden)

Anna Antonyová

2015-10-01

Full Text Available In this research a measurement systemwas developedfor monitoring humidity and temperature in the cavity between the wall and the insulating material in the building envelope. This new technology does not disturb the insulating material during testing. The measurement system can also be applied to insulation fixed ten or twenty years earlier and sufficiently reveals the quality of the insulation. A mathematical model is proposed to characterize the dynamic responses in the cavity between the wall and the building insulation as influenced by weather conditions.These dynamic responses are manifested as a delay of both humidity and temperature changes in the cavity when compared with the changes in the ambient surrounding of the building. The process is then modeled through numerical methods and statistical analysis of the experimental data obtained using the new system of measurement.

Thermal dynamic simulation of wall for building energy efficiency under varied climate environment

Science.gov (United States)

Wang, Xuejin; Zhang, Yujin; Hong, Jing

2017-08-01

Aiming at different kind of walls in five cities of different zoning for thermal design, using thermal instantaneous response factors method, the author develops software to calculation air conditioning cooling load temperature, thermal response factors, and periodic response factors. On the basis of the data, the author gives the net work analysis about the influence of dynamic thermal of wall on air-conditioning load and thermal environment in building of different zoning for thermal design regional, and put forward the strategy how to design thermal insulation and heat preservation wall base on dynamic thermal characteristic of wall under different zoning for thermal design regional. And then provide the theory basis and the technical references for the further study on the heat preservation with the insulation are in the service of energy saving wall design. All-year thermal dynamic load simulating and energy consumption analysis for new energy-saving building is very important in building environment. This software will provide the referable scientific foundation for all-year new thermal dynamic load simulation, energy consumption analysis, building environment systems control, carrying through farther research on thermal particularity and general particularity evaluation for new energy -saving walls building. Based on which, we will not only expediently design system of building energy, but also analyze building energy consumption and carry through scientific energy management. The study will provide the referable scientific foundation for carrying through farther research on thermal particularity and general particularity evaluation for new energy saving walls building.

Quantitative analysis of thermal insulation coatings

DEFF Research Database (Denmark)

Kiil, Søren

2014-01-01

This work concerns the development of simulation tools for mapping of insulation properties of thermal insulation coatings based on selected functional filler materials. A mathematical model, which includes the underlying physics (i.e. thermal conductivity of a heterogeneous two-component coating...

Effect of highly reflective roofing sheet on building thermal loads for a school in Osaka

Directory of Open Access Journals (Sweden)

Yuan Jihui

2017-01-01

Full Text Available Currently, urban heat island (UHI phenomenon and building energy consumptions are becoming serious. Strategies to mitigate UHI and reduce building energy consumptions are implemented worldwide. In Japan, as an effective means of mitigating UHI and saving energy of buildings, highly reflective (HR and green roofs are increasingly used. In order to evaluate the effect of roofs with high reflection and thermal insulation on the energy conservation of buildings, we investigated the roof solar reflectivity of the subject school in Osaka, in which the HR roofing sheet was installed on the roof from 2010. Thermal loads, including cooling and heating loads of the top floor of school, were calculated using the thermal load calculation software, New HASP/ACLD-β. Comparing the thermal loads after HR roofing sheet installation to previous, the annual thermal load decreased about 25 MJ/m2-year and the cooling load decreased about 112 MJ/m2-year. However, the heating load increased about 87 MJ/m2-year in winter. To minimize the annual thermal load, thermal insulation of the roof was also considered be used together with HR roofing sheet in this study. The results showed that the combination of HR roofing sheet and high thermal insulation is more effective to reduce the annual thermal load.

Sprayable Aerogel Bead Compositions With High Shear Flow Resistance and High Thermal Insulation Value

Science.gov (United States)

Ou, Danny; Trifu, Roxana; Caggiano, Gregory

2013-01-01

A sprayable aerogel insulation has been developed that has good mechanical integrity and lower thermal conductivity than incumbent polyurethane spray-on foam insulation, at similar or lower areal densities, to prevent insulation cracking and debonding in an effort to eliminate the generation of inflight debris. This new, lightweight aerogel under bead form can be used as insulation in various thermal management systems that require low mass and volume, such as cryogenic storage tanks, pipelines, space platforms, and launch vehicles.

Building thermal loads: A case study for David Hellen Petta public secondary school

CSIR Research Space (South Africa)

Kumirai, T

2013-03-01

Full Text Available This chapter assesses the impact of appropriate passive interventions on building thermal loads. The passive interventions investigated are ceiling insulation, wall insulation, attic ventilation, natural ventilation and roof absorptance and also...

Temperature and press load stimulation on thermal transport in fibrous and porous composite insulators

International Nuclear Information System (INIS)

Rehman, M.A.; Maqsood, A.

2006-01-01

Thermal transport properties of synthetic pliable insulators are measured as a function of applied pressure at constant temperatures. Advantageous Transient Plane Source (ATPS) method is used for the simultaneous measurement of thermal conductivity and thermal diffusivity of these materials and heat capacity per unit volume is then calculated. Three samples namely foam, closed cell foam and fiber glass are subjected to press load, taking into account the flexibility and sustainability of the samples and the requirements of the technique used. The thermal data of the samples were determined within the temperature range (300-414K) and pressure range (Normal -15kPa). These materials are used for thermal insulation and temperature control of air-conditioned space, acoustic and sound insulation, agriculture and fishery, sports and leisure goods, building and civil engineering, industrial packaging cold storage ware house, boiler work and other electric appliances, so they are helpful in reducing energy losses. (author)

Performance investigation of heat insulation solar glass for low-carbon buildings

International Nuclear Information System (INIS)

Cuce, Erdem; Young, Chin-Huai; Riffat, Saffa B.

2014-01-01

Highlights: • U-value of HISG is found to be 1.10 W/m 2 K. • Maximum temperature difference is achieved by HISG with 12.70 °C. • HISG provides two times better insulation than standard double glazed windows. • HISG generates over 40 W electricity from a glazing surface of 0.66 m 2 . • 100% of UV in incoming solar radiation is absorbed by HISG. - Abstract: Heat insulation solar glass (HISG), which has been recently developed by Professor Chin-Huai Young in Taiwan is an extraordinary glazing technology for low/zero carbon buildings. HISG differs from traditional glazing technologies with its ability of producing electricity. It also offers some additional features such as thermal insulation, sound insulation, self-cleaning and energy saving. In this work, thermal insulation, power generation and optical performance of HISG are experimentally investigated. Thermal insulation performance of HISG is analysed through standardized co-heating test methodology, and the results are compared with different traditional double glazed window samples. For the power generation and optical performance of HISG, two samples (air filled HISG and Argon filled HISG) are experimentally investigated in real and simulated operating conditions. The results indicate that both configurations show similar performance in terms of power generation. Under a solar intensity of 850 W/m 2 , over 40 W electrical power is achieved from HISG samples with a glazing area of 0.66 m 2 . Performance of samples under solar simulator is not found to be promising due to the absence of UV and IR parts in the artificial light source. In terms of thermal insulation ability, HISG is also found to be attractive. The average U-value of HISG is determined to be 1.10 W/m 2 K, which is two times better than standard double glazed windows. Some simulation results for two different cities (Taipei, Taiwan and Nottingham, UK) demonstrating the energy saving potential of HISG are also presented

Design and assembly technology for the thermal insulation of the W7-X cryostat

Energy Technology Data Exchange (ETDEWEB)

Risse, K., E-mail: konrad.risse@ipp.mpg.de [Max-Planck-Institut fuer Plasmaphysik (IPP), Euratom Association, Wendelsteinstrasse 1, D-17491 Greifswald (Germany); Nagel, M.; Pietsch, M.; Braatz, A. [Max-Planck-Institut fuer Plasmaphysik (IPP), Euratom Association, Wendelsteinstrasse 1, D-17491 Greifswald (Germany); Binni, A. [MAN Diesel and Turbo SE, Dpt. OSA, Werftstrasse 17, D-94469 Deggendorf (Germany); Posselt, H. [Linde AG Engineering Div., Dr.-Carl-von-Linde-Strasse 6-14, D-82049 Hoellriegelskreuth (Germany)

2011-10-15

The Max-Planck-Institut fuer Plasmaphysik in Greifswald is building up the stellarator fusion experiment Wendelstein 7-X (W7-X). To operate the superconducting magnet system the vacuum and the cold structures are protected by a thermal insulated cryostat. The plasma vessel forms the inner cryostat wall, the outer wall is realised by a thermal insulated outer vessel. In addition 254 thermal insulated ports are fed through the cryogenic vacuum to allow the access to the plasma vessel for heating systems, supply lines or plasma diagnostics. The thermal insulation is being manufactured and assembled by MAN Diesel and Turbo SE (Germany). It consists of a multi-layer insulation (MLI) made of aluminized Kapton with a silk like fibreglass spacer and a thermal shield covering the inner cryostat surfaces. The shield on the plasma vessel is made of fibreglass reinforced epoxy resin with integrated copper meshes. The outer vessel insulation is made of brass panels with an average size of 3.3 x 2.0 m{sup 2}. Cooling loops made of stainless steel are connected via copper strips to the brass panels. Especially the complex 3 D shape of the plasma vessel, the restricted space inside the cryostat and the consideration of the operational component movements influenced the design work heavily. The manufacturing and the assembly has to fulfil stringent geometrical tolerances e.g. for the outer vessel panels +3/-2 mm.

Design and assembly technology for the thermal insulation of the W7-X cryostat

International Nuclear Information System (INIS)

Risse, K.; Nagel, M.; Pietsch, M.; Braatz, A.; Binni, A.; Posselt, H.

2011-01-01

The Max-Planck-Institut fuer Plasmaphysik in Greifswald is building up the stellarator fusion experiment Wendelstein 7-X (W7-X). To operate the superconducting magnet system the vacuum and the cold structures are protected by a thermal insulated cryostat. The plasma vessel forms the inner cryostat wall, the outer wall is realised by a thermal insulated outer vessel. In addition 254 thermal insulated ports are fed through the cryogenic vacuum to allow the access to the plasma vessel for heating systems, supply lines or plasma diagnostics. The thermal insulation is being manufactured and assembled by MAN Diesel and Turbo SE (Germany). It consists of a multi-layer insulation (MLI) made of aluminized Kapton with a silk like fibreglass spacer and a thermal shield covering the inner cryostat surfaces. The shield on the plasma vessel is made of fibreglass reinforced epoxy resin with integrated copper meshes. The outer vessel insulation is made of brass panels with an average size of 3.3 x 2.0 m 2 . Cooling loops made of stainless steel are connected via copper strips to the brass panels. Especially the complex 3 D shape of the plasma vessel, the restricted space inside the cryostat and the consideration of the operational component movements influenced the design work heavily. The manufacturing and the assembly has to fulfil stringent geometrical tolerances e.g. for the outer vessel panels +3/-2 mm.

Artificial heart system thermal insulation component development

International Nuclear Information System (INIS)

Svedberg, R.C.; Buckman, R.W. Jr.

1975-01-01

A concentric cup vacuum multifoil insulation system has been selected by virtue of its size, weight, and thermal performance to insulate the hot radioisotope portion of the thermal converter of an artificial implantable heart system. A factor of 2 improvement in thermal performance, based on the heat loss per number of foil layers (minimum system weight and volume) has been realized over conventional spiral wrapped multifoil vacuum insulation. This improvement is the result of the concentric cup construction to maintain a uniform interfoil spacing and the elimination of corner heat losses. Based on external insulation system dimensions (surface area in contact with host body), heat losses of 0.019 W/ cm 2 at 1140 0 K (1600 0 F) and 0.006 W/cm 2 at 920 0 K (1200 0 F) have been achieved. Factors which influence thermal performance of the nickel foil concentric cup insulation system include the number of cups, configuration and method of application of zirconia (ZrO 2 ) spacer material, system pressure, emittance of the cups, and operating temperature

Transparent thermal insulation for prefabricated school buildings; Einsatz transparenter Waermedaemmung an Schulgebaeuden in praefabrizierter Bauweise

Energy Technology Data Exchange (ETDEWEB)

Russ, C. [Fraunhofer-Institut fuer Solare Energiesysteme (ISE), Freiburg im Breisgau (Germany). Gruppe Solares Bauen; Buchmann, R. [Leipzigprojekt GmbH, Leipzig (Germany); Duesterhoeft, A. [Holz- und Leichtmetallbau GmbH, Leipzig (Germany)

1997-12-31

The existing schools in the new federal states built from prefabricated elements need to be modernized in order to reduce their energy demand. Fitting some 300 square metres of transparent thermal insulation to the south side of a house front may lead to a cut in its thermal energy demand by 74 per cent. This energy consumption is by 12 kWh per square metre lower than the one obtained with opaque thermal insulation. The results of the first demonstration project are described. (MSK) [Deutsch] Die in den neuen Bundeslaendern vorhandenen Schulen in vorgefertigter Bauweise sind energetisch sanierungsbeduerftig. Werden im Rahmen einer Sanierung ca. 300qm transparente Waermedaemmung an der suedorientierten Fassade eingesetzt, so kann der Heizwaermebedarf um 74% herabgesetzt werden. Das sind 12 kWh/qm weniger als bei dem vergleichsweisen Einsatz einer opaken Waermedaemmung. Im Folgenden werden die Ergebnisse des ersten Demonstrationsprojekts beschrieben.

Study of thermal conductivity of multilayer insulation

International Nuclear Information System (INIS)

Dutta, D.; Sundaram, S.; Nath, G.K.; Sethuram, N.P.; Chandrasekharan, T.; Varadarajan, T.G.

1994-01-01

This paper presents experimental determination of the apparent thermal conductivity of multilayer insulation for a cryogenic system. The variation of thermal conductivity with residual gas pressure is studied and the optimum vacuum for good insulating performance is determined. Evaporation loss technique for heat-inleak determination is employed. (author)

Concrete elements with better insulation and less thermal bridge effect; Betonelementer med bedre isolering og mindre kuldebroer

Energy Technology Data Exchange (ETDEWEB)

Monefeldt Tommerup, H

2000-09-01

In this project new concrete sandwich panel solutions with better thermal properties have been developed, usable for highly-insulated buildings, responding to the needs that occur when the demands to the permissible energy consumption for heating is further increased. This is expected to happen in 2005. The improved thermal properties have been obtained without increasing the costs more than of the extra insulation. Removing concrete ribs at window reveals and at horizontal joints enables a thermal improvement as well as reduced costs due to simpler manufacturing of the panel. A natural grouping of concrete sandwich panels into two categories formed the basis of the work. One is panels with covering concrete reveals as typically used in residential housing and office buildings. The other is about panels with load bearing ribs serving as columns, typically used in industrial and commercial building. Of course there are panels that are a combination of the two categories, but this fact has not been crucial for the analyses. (au)

Method of manufacturing a thermally insulating body

Energy Technology Data Exchange (ETDEWEB)

McWilliams, J.A.; Morgan, D.E.; Jackson, J.D.

1988-10-11

A method of manufacturing a microporous thermally insulating body comprises mixing together a finely divided microporous insulating material such as silica aerogel or pyrogenic silica and a solid ammonia-generating compound in particulate form, and compressing the mixture to form a thermally insulating body. The ammonia-generating compound is dispersed evenly throughout the insulating material and may comprise, for example, ammonium carbonate, ammonium acetate or urea. Preferably, the ammonia-generating compound comprises a mixture of about one third by weight of ammonium carbonate and about two thirds by weight of ammonium bicarbonate together with a small proportion of magnesium oxide. Experiments are described which illustrate the manufacturing process. 6 tabs.

Study of thermal conductivity of multilayer insulation

Energy Technology Data Exchange (ETDEWEB)

Dutta, D; Sundaram, S; Nath, G K; Sethuram, N P; Chandrasekharan, T; Varadarajan, T G [Heavy Water Division, Bhabha Atomic Research Centre, Mumbai (India)

1994-06-01

This paper presents experimental determination of the apparent thermal conductivity of multilayer insulation for a cryogenic system. The variation of thermal conductivity with residual gas pressure is studied and the optimum vacuum for good insulating performance is determined. Evaporation loss technique for heat-inleak determination is employed. (author). 3 refs., 3 figs.

Thermal insulation coating based on water-based polymer dispersion

Directory of Open Access Journals (Sweden)

Panchenko Iuliia

2018-01-01

Full Text Available For Russia, due to its long winter period, improvement of thermal insulation properties of envelope structures by applying thermal insulation paint and varnish coating to its inner surface is considered perspective. Thermal insulation properties of such coatings are provided by adding aluminosilicate microspheres and aluminum pigment to their composition. This study was focused on defining the effect of hollow aluminosilicate microspheres and aluminum pigment on the paint thermal insulation coating based on water-based polymer dispersion and on its optimum filling ratio. The optimum filling ratio was determined using the method of critical pigment volume concentration (CPVC. The optimum filling ratio was found equal to 55%.

Thermal-performance study of liquid metal fast breeder reactor insulation

International Nuclear Information System (INIS)

Shiu, K.K.

1980-09-01

Three types of metallic thermal insulation were investigated analytically and experimentally: multilayer reflective plates, multilayer honeycomb composite, and multilayer screens. Each type was subjected to evacuated and nonevacuated conditions, where thermal measurements were made to determine thermal-physical characteristics. A variation of the separation distance between adjacent reflective plates of multilayer reflective plates and multilayer screen insulation was also experimentally studied to reveal its significance. One configuration of the multilayer screen insulation was further selected to be examined in sodium and sodium oxide environments. The emissivity of Type 304 stainless steel used in comprising the insulation was measured by employing infrared technology. A comprehensive model was developed to describe the different proposed types of thermal insulation. Various modes of heat transfer inherent in each type of insulation were addressed and their relative importance compared. Provision was also made in the model to allow accurate simulation of possible sodium and sodium oxide contamination of the insulation. The thermal-radiation contribution to heat transfer in the temperature range of interest for LMFBR's was found to be moderate, and the suppression of natural convection within the insulation was vital in preserving its insulating properties. Experimental data were compared with the model and other published results. Moreover, the three proposed test samples were assessed and compared under various conditions as viable LMFBR thermal insulations

Thermal insulator made of ultra fine particles of silica. Chobiryushi silica kei dannetsuzai

Energy Technology Data Exchange (ETDEWEB)

Eguchi, T.

1991-05-30

An overview was presented of properties and applications of thermal insulator made of ultra fine powder of silica, MICROTHERM. The thermal conductivity of MICROTHERM is as low as (1/3) - (1/4) of that of conventional thermal insulator, because it is mainly composed of fumed silica or aero gel and formed into porous structure. In addition, metal oxide of special particle size is added to it in order to reject the radiative heat. The thermal insulation property and the mechanical strength of MICROTHERM is not affected by a sudden change in temperature and moisture. The standard type of MICROTHERM can be used at a temperature up to 950 {degree}C, while the high temperature type MICROTHERM can stand a high temperature up to 1025 {degree}C for long period of time. The thickness of insulator can be reduced markedly by using MICROTHERM as compared with the use of conventional insulating materials. Many new products in which MICROTHERM is used came into market. New type kilt, Semi-cylindrical block, Super high temperature MICROTHERM are just a few examples. Variety of application and energy saving effect are attracting public attention. 11 figs.

Needle-Bonded Electromagnetic Shielding Thermally Insulating Nonwoven Composite Boards: Property Evaluations

Directory of Open Access Journals (Sweden)

Jia-Horng Lin

2016-10-01

Full Text Available Complicated environmental problems inevitably arise when technology advances. One major environmental problem is the presence of electromagnetic radiation. Long-term exposure to electromagnetic radiation can damage people’s health in many ways. Therefore, this study proposes producing composite boards with electromagnetic shielding effectiveness and thermal insulation by utilizing the structures and properties of materials. Different combinations of flame-retardant polyester fiber (FR fiber, recycled far-infrared polyester fiber (FI fiber, and 4D low-melting-point fibers (LM fiber were made into flame-retardant and thermally insulating matrices. The matrices and carbon fiber (CF woven fabric in a sandwich-structure were needle-punched in order to be tightly compact, and then circularly heat dried in order to have a heat set and reinforced structure. The test results indicate that Polyester (PET/CF composite boards are mechanically strong and have thermal insulation and electromagnetic shielding effectiveness at a frequency between 0.6 MHz and 3 GHz.

Thermal insulation of high temperature reactors

International Nuclear Information System (INIS)

Cornille, Y.

1975-01-01

Operating conditions of HTR thermal insulation are given and heat insulators currently developed are described (fibers kept in position by metallic structures). For future applications and higher temperatures, research is directed towards solutions using ceramics or associating fibers and ceramics [fr

Insulation systems of the building construtions

Directory of Open Access Journals (Sweden)

Rumiantcev Boris

2016-01-01

Full Text Available Constructions of the exterior insulation and decoration combines materials of different functionality and constructive solutions allows to these materials to demonstrate their efficiency to the great extent. Fire safety of buildings is mandatory requirement for building systems. Some insulating material may belong to the group of combustible, but their use in structures so as to minimize the risk of fire. On the other hand, there are special designs, in which non-flammable insulation acts as a flame retardant barrier. In the article carried systematization of construction systems used in the flat and pitched roof during the insulation and wall covering and facades. Taking into account the experience of leading firms were considered the application features of using exterior finish systems: construction solutions, requirements for materials and recommendations about the installation these systems.The article deals with the construction ventilated roofing system of two types: flat roof and pitched roof seam. In the first case, the ventilation system is created using milled insulation boards in the second - by a ventilated gap. In both cases the natural convection of air in the air cavities. Ensuring operational stability insulation is laid on the stages of production of heat-insulating materials. It is important: firstly responsible execution of all process operations associated with providing regulatory properties of materials and secondly, the performance of additional operations associated with the produc-tion of materials, working in a specific design. An example of a material whose properties can modify for a particular application, are milled mineral wool (with air channels for systems of ventilated flat roof.

Integration of thermal insulation coating and moving-air-cavity in a cool roof system for attic temperature reduction

International Nuclear Information System (INIS)

Yew, M.C.; Ramli Sulong, N.H.; Chong, W.T.; Poh, S.C.; Ang, B.C.; Tan, K.H.

2013-01-01

Highlights: • A novel integrated cool roof system for attic temperature reduction is introduced. • 13 °C temperature reduction achieved due to its efficient heat transfer mechanism. • Aluminium tube cavity of the roof is able to reduce the attic temperature. • This positive result is due to its efficient heat reflection and hot air rejection. • Thermal insulation coating incorporates the usage of eggshell waste as bio-filler. - Abstract: Cool roof systems play a significant role in enhancing the comfort level of occupants by reducing the attic temperature of the building. Heat transmission through the roof can be reduced by applying thermal insulation coating (TIC) on the roof and/or installing insulation under the roof of the attic. This paper focuses on a TIC integrated with a series of aluminium tubes that are installed on the underside of the metal roof. In this study, the recycled aluminium cans were arranged into tubes that act as a moving-air-cavity (MAC). The TIC was formulated using titanium dioxide pigment with chicken eggshell (CES) waste as bio-filler bound together by a polyurethane resin binder. The thermal conductivity of the thermal insulation paint was measured using KD2 Pro Thermal Properties Analyzer. Four types of cool roof systems were designed and the performances were evaluated. The experimental works were carried out indoors by using halogen light bulbs followed by comparison of the roof and attic temperatures. The temperature of the surrounding air during testing was approximately 27.5 °C. The cool roof that incorporated both TIC and MAC with opened attic inlet showed a significant improvement with a reduction of up to 13 °C (from 42.4 °C to 29.6 °C) in the attic temperature compared to the conventional roof system. The significant difference in the results is due to the low thermal conductivity of the thermal insulation paint (0.107 W/mK) as well as the usage of aluminium tubes in the roof cavity that was able to transfer

Thermal protection and refurbishment of an old building. Lectures; Waermeschutz und Altbausanierung. Vortraege

Energy Technology Data Exchange (ETDEWEB)

NONE

2011-07-01

Within the 22nd Hanseatic Reconstruction Symposium at the Baltic Seaside Heringsdorf/Usedom (Federal Republic of Germany) from 3rd to 5th November 2011, the following lectures were held: (1) Energetic refurbishment possibilities for building within existing properties by means of representative examples (F. Deitschum); (2) Constructional thermal insulation and indoor climate - for the good of the environment? (S. Groer); (3) Innovative insulating materials for the structural refurbishment? (O. Fechner); (4) Energetic half-timbering refurbishment (K. Lissner); (5) Wooden solar facades for existing buildings (U. Schwarz); (6) Timber beam bowls in a historic brickwork (U. Mueller); (7) Timber beam bowls and interior insulation (U. Ruisinger); (8) Innovative solutions for cavity filling insulations (A. Stefenelli); (9) Thermal insulating plaster - also for historical buildings (T. Stahl); (10) Experimental tension analysis of the structural behaviour of historical cross vaults (A.-J. Petereit); (10) Investigation of the increase of the flexural strength of stonework constructions with self-compacting steel fibre reinforced concrete (D. Haessler); (11) Dry and dense - the modified WTA leaflet 4-6, 'Subsequent sealing of components in contact with soil' - Content and innovations (R. Spirgatis); (12) What does the new standard DIN 68800 hold? (H. Willeitner); (13) News from the standard DIN 18195 waterproofing of buildings (H.-P. Sommer); (14) Liability of planning of the offering entrepreneur (H. Immoor); (15) Climate change and preservation of structures (W. Zillig); (16) Typical problems and deficiencies of the energetic refurbishment of old store buildings (H. Boehmer); (17) When do ex post horizontal sealings with injection agents make sense - Fundamentals for evaluation, planning and execution (F.-J. Hoelzen); (18) Drying up behaviour of stonework of different quality and at different variants of insulation (F. Antretter).

Thermal comfort optimisation of vernacular rural buildings: passive solutions to retrofit a typical farmhouse in central Italy

Directory of Open Access Journals (Sweden)

Maria Elena Menconi

2017-06-01

Full Text Available An adequate retrofitting of traditional rural buildings requires to preserve their formal characteristics and to understand the constructive elements that compose them and which are different in different geographical areas. This paper analyses the typical farmhouses in central Italy. Starting from the definition of a vernacular building model, the paper analyses its performance in terms of thermal comfort and energy efficiency. The methodology involves the use of energy dynamic simulations coupled with optimisation techniques aimed to identify the best combinations of insulating materials in terms of choice of material and its optimal location in the envelope. The paper demonstrates the good thermal and energy performance of farmhouses in central Italy. The results of the optimisation process showed that in these buildings, with the addition of insulation materials with low conductivity the perceived discomfort in the inhabited areas of the building can be reduced by 79% and the energy consumption related to heating can be reduced by 77%. The level of insulation of the pavement that separates the ground and first floor needs to be more moderate to promote the heat flow between floors during summer. The sensitivity analysis shows that the most influential component for thermal comfort is the roof insulation.

Overview of thermal conductivity models of anisotropic thermal insulation materials

Science.gov (United States)

Skurikhin, A. V.; Kostanovsky, A. V.

2017-11-01

Currently, the most of existing materials and substances under elaboration are anisotropic. It makes certain difficulties in the study of heat transfer process. Thermal conductivity of the materials can be characterized by tensor of the second order. Also, the parallelism between the temperature gradient vector and the density of heat flow vector is violated in anisotropic thermal insulation materials (TIM). One of the most famous TIM is a family of integrated thermal insulation refractory material («ITIRM»). The main component ensuring its properties is the «inflated» vermiculite. Natural mineral vermiculite is ground into powder state, fired by gas burner for dehydration, and its precipitate is then compressed. The key feature of thus treated batch of vermiculite is a package structure. The properties of the material lead to a slow heating of manufactured products due to low absorption and high radiation reflection. The maximum of reflection function is referred to infrared spectral region. A review of current models of heat propagation in anisotropic thermal insulation materials is carried out, as well as analysis of their thermal and optical properties. A theoretical model, which allows to determine the heat conductivity «ITIRM», can be useful in the study of thermal characteristics such as specific heat capacity, temperature conductivity, and others. Materials as «ITIRM» can be used in the metallurgy industry, thermal energy and nuclear power-engineering.

Thermal insulation layer for the vacuum containers of a thermonuclear device

International Nuclear Information System (INIS)

Nishikawa, Masana; Yamada, Masao; Kameari, Akihisa; Niikura, Setsuo.

1980-01-01

Purpose: To prevent temperature rise of a thermal insulation layer for a vacuum container of a thermonuclear device higher than allowable value when irradiated by neutron by constructing the layer of a cooling unit in thermal insulation material. Constitution: A metal plate attached with cooling pipes is buried in a thermal insulation material forming a thermal insulation layer to form the layer provided between a vacuum container of a thermonuclear device and a shield. (Yoshihara, H.)

Soup Cooking by Thermal Insulation Method

OpenAIRE

佐藤, 辰江; 根本, 勢子; サトウ, タツエ; ネモト, セイコ; TATSUE, SATO; SEIKO, NEMOTO

1992-01-01

In order to examine the thermal insulation method of soup cooking, we cooked two kinds of soup. The soup cooked by thermal insulation method was compared with the soup cooked by standard boiling method. ln sensory test, it was more aromatic and palatable than the soup by boiling, and some panels commented that it was rather mild. The measured values of pH, specific gravity, acidity and amount of dry weight of souble solids, total-N, formal-N of the soup cooked by the two methods mentioned abo...

Parametric study of the thermal performance of a typical administrative building in the six thermal zones according to the RTCM, using TRNSYS

Directory of Open Access Journals (Sweden)

Abdelghafour LAMRANI

2018-01-01

Full Text Available In this work, we present a parametric study of a new administrative building, located in El-Ksar El Kebir region (Morocco. In order to have a building that complies with the RTCM in a technically and economically sound manner, we have carried out a number of interventions to insulate the components of the building, namely external walls, exposed roofs and openings. In this perspective, we have modelled the building envelope as a multi-zone building in TRNSYS and we have adopted an occupation scenario for this type of building. After determining the optimal insulation solutions, we simulated the administrative building in the five other thermal zones, to determine its feasibility in the latter.

Estimation of thermal insulation performance in multi-layer insulator for liquid helium pipe

International Nuclear Information System (INIS)

Shibanuma, Kiyoshi; Kuriyama, Masaaki; Shibata, Takemasa

1991-01-01

For a multi-layer insulator around the liquid helium pipes for cryopumps of JT-60 NBI, a multi-layer insulator composed of 10 layers, which can be wound around the pipe at the same time and in which the respective layers are in concentric circles by shifting them in arrangement, has been developed and tested. As the result, it was shown that the newly developed multi-layer insulator has better thermal insulation performance than the existing one, i.e. the heat load of the newly developed insulator composed of 10 layers was reduced to 1/3 the heat load of the existing insulator, and the heat leak at the joint of the insulator in longitudinal direction of the pipe was negligible. In order to clarify thermal characteristics of the multi-layer insulator, the heat transfer through the insulator has been analyzed considering the radiation heat transfer by the netting spacer between the reflectors, and the temperature dependence on the emissivities and the heat transmission coefficients of these two components of the insulator. The analytical results were in good agreements with the experimental ones, so that the analytical method was shown to be valid. Concerning the influence of the number of layers and the layer density on the insulation performance of the insulator, analytical results showed that the multi-layer insulator with the number of layer about N = 20 and the layer density below 2.0 layer/mm was the most effective for the liquid helium pipe of a JT-60 cryopump. (author)

On the Effects of Variation of Thermal Conductivity in Buildings in the Italian Construction Sector

Directory of Open Access Journals (Sweden)

Umberto Berardi

2018-04-01

Full Text Available Stationary and dynamic heat and mass transfer analyses of building components are an essential part of energy efficient design of new and retrofitted buildings. Generally, a single constant thermal conductivity value is assumed for each material layer in construction components. However, the variability of thermal conductivity may depend on many factors; temperature and moisture content are among the most relevant ones. A linear temperature dependence of thermal conductivity has been found experimentally for materials made of inorganic fibers such as rockwool or fiberglass, showing lower thermal conductivities at lower temperatures. On the contrary, a nonlinear temperature dependence has been found for foamed insulation materials like polyisocyanurate, with a significant deviation from linear behavior. For this reason, thermal conductivity assumptions used in thermal calculations of construction components and in whole-building performance simulations have to be critically questioned. This study aims to evaluate how temperature affects thermal conductivity of materials in building components such as exterior walls and flat roofs in different climate conditions. Therefore, experimental conductivities measured for four common insulation materials have been used as a basis to simulate the behavior of typical construction components in three different Italian climate conditions, corresponding to the cities of Turin, Rome, and Palermo.

Investigation of the Mechanical Properties of Hybrid Carbon-Hemp Laminated Composites Used as Thermal Insulation for Different Industrial Applications

Directory of Open Access Journals (Sweden)

M. L. Scutaru

2014-04-01

Full Text Available Carbon-hemp composite laminate provides good thermal properties. For this reason this type of material is presently being used for various applications like insulator for airplanes, spaceships, nuclear reactors, and so forth. Unfortunately their mechanical properties are less studied. These characteristics are very important since they should be guaranteed also for important mechanical stress in addition to the thermal one. The present paper presents a study regarding the impact testing of some hybrid composite laminate panels based on polyester resin reinforced with both carbon and hemp fabric. The effects of different impact speeds on the mechanical behavior of these panels have been analyzed. The paper lays stress on the characterization of this hybrid composite laminate regarding the impact behavior of these panels by dropping a weight with low velocity.

Experiment on thermal insulation and sodium deposition of shield plug

International Nuclear Information System (INIS)

Hashiguchi, K.; Honda, M.; Shiratori, H.; Ozaki, O.; Suzuki, M.

1986-01-01

A series of experiments on temperature distribution and thermal insulation characteristics was conducted using a reduced scale model of LMFBR shield plug. Observation and measurement of sodium deposition were also conducted on the model after the experiment. The effect of annulus natural convection was clarified for temperature and the thermal insulation characteristics from evaluating the result. Temperature distribution analysis was conducted successfully by combining the general purpose structural analysis program NASTRAN and vertical annulus natural convection analysis program VANAC. Moreover, significant effect was substantiated for the annulus convection barrier to increase the thermal insulation performance, narrow horizontal gap structure to prevent sodium deposition and thermal insulation plates. (author)

Thermal insulation product for insulation, especially in nuclear power engineering, and method of its production

International Nuclear Information System (INIS)

Veselovsky, P.; Zink, S.; Balacek, P.; Mares, I.

1989-01-01

The insulation consists of a sewn fabric cover made of inorganic fibers, in which the fiber filling is reinforced mechanically by dense point interweaving. The inorganic fibers, 1 to 5 μm in diameter, consist of min. 97 wt.% mixture of aluminium and silicon oxides in the vitreous state. The fibers making up the cover consist of min. 95% silicon, aluminium, calcium, magnesium and boron oxides in the vitreous state; the rest can consist of alloy steel fibres. The bulk density of the insulation is 70 to 150 kg/m 3 . The product is highly resistant to temperature and to the action of chemicals, water, and acid and alkaline deactivation solutions. Its manufacture is fast and undemanding. It is designed for thermal insulation of pipes, tanks and valves in nuclear power plants. (M.D.). 2 figs

5th Duisburg thermal insulation days. Fuenfte Duisburger Waermedaemm-Tage

Energy Technology Data Exchange (ETDEWEB)

Agst, J. (ed.)

1989-01-01

This volume contains 18 specialist lectures mainly about the problems of thermal insulation in industrial furnaces and facility engineering. Among the subjects are: formed parts, monolithic lining materials and fillers of vermiculite; pyro-block-modular systems for furnaces (of the company DYKO-Morgan Fasertechnik); microporous insulating materials (KAOWOOL); properties of lightweight refractory bricks; thermal insulation in induction furnaces; vacuum moulded parts in electric furnace engineering; high temperature insulating materials with ceramic fibres; microtherm insulating materials. (MM).

Mechanical, Thermal and Functional Properties of Green Lightweight Foamcrete

Directory of Open Access Journals (Sweden)

Md Azree Othuman Mydin

2012-09-01

Full Text Available In recent times, the construction industry has revealed noteworthy attention in the use of lightweight foamcrete as a building material due to its many favourable characteristics such as lighter weight, easy to fabricate, durable and cost effective. Foamcrete is a material consisting of Portland cement paste or cement filler matrix (mortar with a homogeneous pore structure created by introducing air in the form of small bubbles. With a proper control in dosage of foam and methods of production, a wide range of densities (400 – 1600 kg/m 3 of foamcrete can be produced thus providing flexibility for application such as structural elements, partition, insulating materials and filling grades. Foamcrete has so far been applied primarily as a filler material in civil engineering works. However, its good thermal and acoustic performance indicates its strong potential as a material in building construction. The focus of this paper is to classify literature on foamcrete in terms of its mechanical, thermal and functional properties.

Correlations in hydrothermal properties of building insulation

International Nuclear Information System (INIS)

Antonyová, A

2013-01-01

The contribution comprises analysis that is based on scientific work as a part of participation on the international research project carried out at the University of Prešov in Prešov and Vienna University of Technology entitled 'Detection and Management of Risk Processes in Building Insulation' and numbered SRDA SK-AT-0008-10. Statistical approach with correlations among humidity, time and temperature values in the space between the wall and building insulation uses the set of data obtained during the measurement series as testing using a new technology with equipment that does not influence the environment properties in the space. Therefore such real mapping can bring a real picture of possible condensation as a risk process in the building envelope.

Nuclear reactor vessel fuel thermal insulating barrier

Science.gov (United States)

Keegan, C. Patrick; Scobel, James H.; Wright, Richard F.

2013-03-19

The reactor vessel of a nuclear reactor installation which is suspended from the cold leg nozzles in a reactor cavity is provided with a lower thermal insulating barrier spaced from the reactor vessel that has a hemispherical lower section that increases in volume from the center line of the reactor to the outer extent of the diameter of the thermal insulating barrier and smoothly transitions up the side walls of the vessel. The space between the thermal insulating harrier and the reactor vessel forms a chamber which can be flooded with cooling water through passive valving to directly cool the reactor vessel in the event of a severe accident. The passive inlet valve for the cooling water includes a buoyant door that is normally maintained sealed under its own weight and floats open when the cavity is Hooded. Passively opening steam vents are also provided.

INSUL, Calculation of Thermal Insulation of Various Materials Immersed in He

International Nuclear Information System (INIS)

Kinkead, A.N.; Pitchford, B.E.

1977-01-01

1 - Nature of the physical problem solved: Performance of thermal insulation immersed in helium. 2 - Method of solution: Mineral fibre, metal fibre and metallic multi-layer foils are studied. An approximate analysis for performance evaluation of multi-layer insulation in vertical gas spaces including the regime between fully suppressed natural convection and that for which an accepted power relationship applies is included

Model-based analysis of thermal insulation coatings

DEFF Research Database (Denmark)

Kiil, Søren

2014-01-01

Thermal insulation properties of coatings based on selected functional filler materials are investigated. The underlying physics, thermal conductivity of a heterogeneous two-component coating, and porosity and thermal conductivity of hollow spheres (HS) are quantified and a mathematical model for...

Thermal mass impact on energy performance of a low, medium and heavy mass building in Belgrade

Directory of Open Access Journals (Sweden)

Anđelković Bojan V.

2012-01-01

Full Text Available Heavy mass materials used in building structures and architecture can significantly affect building energy performance and occupant comfort. The purpose of this study was to investigate if thermal mass can improve the internal environment of a building, resulting in lower energy requirements from the mechanical systems. The study was focused on passive building energy performance and compared annual space heating and cooling energy requirements for an office building in Belgrade with several different applications of thermal mass. A three-dimensional building model was generated to represent a typical office building. Building shape, orientation, glazing to wall ratio, envelope insulation thickness, and indoor design conditions were held constant while location and thickness of building mass (concrete was varied between cases in a series of energy simulations. The results were compared and discussed in terms of the building space heating and cooling energy and demand affected by thermal mass. The simulation results indicated that with addition of thermal mass to the building envelope and structure: 100% of all simulated cases experienced reduced annual space heating energy requirements, 67% of all simulated cases experienced reduced annual space cooling energy requirements, 83% of all simulated cases experienced reduced peak space heating demand and 50% of all simulated cases experienced reduced peak space cooling demand. The study demonstrated that there exists a potential for reducing space heating and cooling energy requirements with heavy mass construction in the analyzed climate region (Belgrade, Serbia.

Thermal Transport in High-Strength Polymethacrylimide (PMI) Foam Insulations

Science.gov (United States)

Qiu, L.; Zheng, X. H.; Zhu, J.; Tang, D. W.; Yang, S. Y.; Hu, A. J.; Wang, L. L.; Li, S. S.

2015-11-01

Thermal transport in high-strength polymethacrylimide (PMI) foam insulations is described, with special emphasis on the density and temperature effects on the thermal transport performance. Measurements of the effective thermal conductivity are performed by a freestanding sensor-based 3ω method. A linear relationship between the density and the effective thermal conductivity is observed. Based on the analysis of the foam insulation morphological structures and the corresponding geometrical cell model, the quantitative contribution of the solid conductivity and the gas conductivity as well as the radiative conductivity to the total effective thermal conductivity as a function of the density and temperature is calculated. The agreement between the curves of the results from the developed model and experimental data indicate the model can be used for PMI foam insulating performance optimization.

Research on thermal insulation for hot gas ducts

International Nuclear Information System (INIS)

Broeckerhoff, P.

1984-01-01

The inner surfaces of prestressed reactor vessels and hot gas ducts of Gas Cooled High Temperature Reactors need internal thermal insulation to protect the pressure bearing walls from high temperatures. The design parameters of the insulation depend on the reactor type. In a PNP-plant temperature and pressure of the cooling medium helium are proposed to be 950 deg. C and 40 bars, respectively. The experimental work was started at KFA in 1971 for the HHT-project using three test facilities. At first metallic foil insulation and stuffed fibre insulating systems, the hot gas ducting shrouds of which were made of metal, have been tested. Because of the elevated helium temperature in case of PNP and the resulting lower strength of the metallic parts the interest was directed to rigid ceramic materials for the spacers and the inner shrouds. This led to modified structures designed by the INTERATOM company. Tests were performed at KFA. The main object of the investigations was to study the influence of temperature, pressure and axial pressure gradients on the thermal efficiency of the structures. Moreover, the temperatures within the insulation, at the pressure tube, and at the elements which bear the inner shrouds were measured. Thermal fluxes and effective thermal conductivities in axial and circumferential direction of the pressure tube are given, mainly for the INTERATOM-design with spherical spacers. (author)

Numerical analysis of the influence of thermal mass, phase change materials and furniture / indoor content on building energy flexibility (long abstract)

DEFF Research Database (Denmark)

Johra, Hicham

investigating the influence of the different types of thermal inertia on buildings energy flexibility. Although the insulation level and thermal mass of a building envelope are the dominant parameters, it appears that indoor content cannot be neglected for lightweight structure building simulations. Finally...

Improvement of methods for calculation of sound insulation in buildings

OpenAIRE

Mašović, Draško B.

2015-01-01

The main object of this work are the methods for calculation of sound insulation based on the classical model of sound propagation in buildings and single-number rating of sound insulation. The aim of the work is inspection of the possibilities for improvement of standard methods for quantification and calculation of sound insulation, in order to achieve higher accuracy of the obtained numerical values and their correlation with subjective impression of the acoustic comfort in buildings. Proc...

Surface Thermal Insulation and Pipe Cooling of Spillways during Concrete Construction Period

Directory of Open Access Journals (Sweden)

Wang Zhenhong

2014-01-01

Full Text Available Given that spillways adopt a hydraulic thin concrete plate structure, this structure is difficult to protect from cracks. The mechanism of the cracks in spillways shows that temperature stress is the major reason for cracks. Therefore, an effective way of preventing cracks is a timely and reasonable temperature-control program. Studies show that one effective prevention method is surface thermal insulation combined with internal pipe cooling. The major factors influencing temperature control effects are the time of performing thermal insulation and the ways of internal pipe cooling. To solve this problem, a spillway is taken as an example and a three-dimensional finite element program and pipe cooling calculation method are adopted to conduct simulation calculation and analysis on the temperature fields and stress fields of concretes subject to different temperature-control programs. The temperature-control effects are then compared. Optimization results show that timely and reasonable surface thermal insulation and water-flowing mode can ensure good temperature-control and anticrack effects. The method has reference value for similar projects.

Thermal analysis of building roof assisted with water heater and ...

Indian Academy of Sciences (India)

D Prakash

2018-03-14

Mar 14, 2018 ... Thermal analysis; building roof; solar water heating system; roof ... These solar collec- ... several benefits, such as its wide range of storage temper- ... rugated plate, rear plate and back insulation material [12]. ..... [7] Weiss W and Rommel M 2008 Process heat collectors. State of the art within Task 33/IV.

Space heating in buildings: thermal diagnosis of an industrial building; Chauffage des batiments: bilan thermique d`un batiment industriel

Energy Technology Data Exchange (ETDEWEB)

Brunet, R.

1996-12-31

The various heat transfer equations used for calculations in thermal diagnosis of an industrial building are reviewed: calculation of the heat losses through walls as a function of building materials, calculation of the energy consumption for heating fresh air (as a function of the air pollution rate in the building), calculation of the total heat losses, the heating energy demand and the annual energy consumption. Data concerning building materials characteristics, insulation and heating loads in the various regions of France, are also presented

Infrared survey of 50 buildings constructed during 100 years: thermal performances and damage conditions

Science.gov (United States)

Ljungberg, Sven-Ake

1995-03-01

Different building constructions and craftsmanship give rise to different thermal performance and damage conditions. The building stock of most industrial countries consists of buildings of various age, and constructions, from old historic buildings with heavy stone or wooden construction, to new buildings with heavy or light concrete construction, or modern steel or wooden construction. In this paper the result from a detailed infrared survey of 50 buildings from six Swedish military camps is presented. The presentation is limited to a comparison of thermal performance and damage conditions of buildings of various ages, functions, and constructions, of a building period of more than 100 years. The result is expected to be relevant even to civilian buildings. Infrared surveys were performed during 1992-1993, with airborne, and mobile short- and longwave infrared systems, out- and indoor thermography. Interpretation and analysis of infrared data was performed with interactive image and analyzing systems. Field inspections were carried out with fiber optics system, and by ocular inspections. Air-exchange rate was measured in order to quantify air leakages through the building envelope, indicated in thermograms. The objects studied were single-family houses, barracks, office-, service-, school- and exercise buildings, military hotels and restaurants, aircraft hangars, and ship factory buildings. The main conclusions from this study are that most buildings from 1880 - 1940 have a solid construction with a high quality of craftsmanship, relatively good thermal performance, due to extremely thick walls, and adding insulation at the attic floor. From about 1940 - 1960 the quality of construction, thermal performance and craftsmanship seem to vary a lot. Buildings constructed during the period of 1960 - 1990 have in general the best thermal performance due to a better insulation capacity, however, also one finds here the greatest variety of problems. The result from this

Effects of aging on the structural, mechanical, and thermal properties of the silicone rubber current transformer insulation bushing for a 500 kV substation.

Science.gov (United States)

Wang, Zhigao; Zhang, Xinghai; Wang, Fangqiang; Lan, Xinsheng; Zhou, Yiqian

2016-01-01

In order to analyze the cracking and aging reason of the silicone rubber current transformer (CT) insulation bushing used for 8 years from a 500 kV alternating current substation, characteristics including Fourier transform infrared (FTIR) spectroscopy, mechanical properties analysis, hardness, and thermo gravimetric analysis have been carried out. The FTIR results indicated that the external surface of the silicone rubber CT insulation bushing suffered from more serious aging than the internal part, fracture of side chain Si-C bond was much more than the backbone. Mechanical properties and thermal stability results illustrated that the main aging reasons were the breakage of side chain Si-C bond and the excessive cross-linking reaction of the backbone. This study can provide valuable basis for evaluating degradation mechanism and aging state of the silicone rubber insulation bushing in electric power field.

Multi-scale cellulose based new bio-aerogel composites with thermal super-insulating and tunable mechanical properties.

Science.gov (United States)

Seantier, Bastien; Bendahou, Dounia; Bendahou, Abdelkader; Grohens, Yves; Kaddami, Hamid

2016-03-15

Bio-composite aerogels based on bleached cellulose fibers (BCF) and cellulose nanoparticles having various morphological and physico-chemical characteristics are prepared by a freeze-drying technique and characterized. The various composite aerogels obtained were compared to a BCF aerogel used as the reference. Severe changes in the material morphology were observed by SEM and AFM due to a variation of the cellulose nanoparticle properties such as the aspect ratio, the crystalline index and the surface charge density. BCF fibers form a 3D network and they are surrounded by the cellulose nanoparticle thin films inducing a significant reduction of the size of the pores in comparison with a neat BCF based aerogel. BET analyses confirm the appearance of a new organization structure with pores of nanometric sizes. As a consequence, a decrease of the thermal conductivities is observed from 28mWm(-1)K(-1) (BCF aerogel) to 23mWm(-1)K(-1) (bio-composite aerogel), which is below the air conductivity (25mWm(-1)K(-1)). This improvement of the insulation properties for composite materials is more pronounced for aerogels based on cellulose nanoparticles having a low crystalline index and high surface charge (NFC-2h). The significant improvement of their insulation properties allows the bio-composite aerogels to enter the super-insulating materials family. The characteristics of cellulose nanoparticles also influence the mechanical properties of the bio-composite aerogels. A significant improvement of the mechanical properties under compression is obtained by self-organization, yielding a multi-scale architecture of the cellulose nanoparticles in the bio-composite aerogels. In this case, the mechanical property is more dependent on the morphology of the composite aerogel rather than the intrinsic characteristics of the cellulose nanoparticles. Copyright © 2015 Elsevier Ltd. All rights reserved.

Synergic effects of thermal mass and natural ventilation on the thermal behaviour of traditional massive buildings

Science.gov (United States)

Gagliano, A.; Nocera, F.; Patania, F.; Moschella, A.; Detommaso, M.; Evola, G.

2016-05-01

The energy policies about energy efficiency in buildings currently focus on new buildings and on existing buildings in case of energy retrofit. However, historic and heritage buildings, that are the trademark of numerous European cities, should also deserve attention; nevertheless, their energy efficiency is nowadays not deeply investigated. In this context, this study evaluates the thermal performance of a traditional massive building situated in a Mediterranean city. Dynamic numerical simulations were carried out on a yearly basis through the software DesignBuilder, both in free-running conditions and in the presence of an air-conditioning (AC) system. The results highlight that the massive envelope of traditional residential buildings helps in maintaining small fluctuations of the indoor temperature, thus limiting the need for AC in the mid-season and in summer. This feature is highly emphasised by exploiting natural ventilation at night, which allows reducing the building energy demand for cooling by about 30%.The research also indicates that, for Mediterranean climate, the increase in thermal insulation does not always induce positive effects on the thermal performance in summer, and that it might even produce an increase in the heat loads due to the transmission through the envelope.

Numerical Analysis of the Impact of Thermal Inertia from the Furniture / Indoor Content and Phase Change Materials on the Building Energy Flexibility

DEFF Research Database (Denmark)

Johra, Hicham; Heiselberg, Per Kvols; Le Dréau, Jérôme

investigating the influence of the different types of thermal inertia on buildings energy flexibility. Although the insulation level and thermal mass of a building envelope are the dominant parameters, it appears that indoor content cannot be neglected for lightweight structure building simulations. Finally...

Thermal insulation of the high-temperature helium-cooled reactors

International Nuclear Information System (INIS)

Kharlamov, A.G.; Grebennik, V.N.

1979-01-01

Unlike the well-known thermal insulation methods, development of high-temperature helium reactors (HTGR) raises quite new problems. To understand these problems, it is necessary to consider behaviour of thermal insulation inside the helium circuit of HTGR and requirements imposed on it. Substantiation of these requirements is given in the presented paper

Thermal performance of various multilayer insulation systems below 80K

International Nuclear Information System (INIS)

Boroski, W.N.; Nicol, T.H.; Schoo, C.J.

1992-04-01

The SSC collider dipole cryostat consists of a vacuum shell operating at room temperature, two thermal shields operating near 80K and 20K respectively, and the superconducting magnet assembly operating near 4K. The cryostat design incorporates multilayer insulation (MLI) blankets to limit radiant heat transfer into the 80K and 20K thermal shields. Also, an MLI blanket is used to impede heat transfer through residual gas conduction into the 4K superconducting magnet assembly. A measurement facility at Fermilab has been used to experimentally optimize the thermal insulation system for the dipole cryostat. Previous thermal measurements have been used to define the 80K MLI system configuration and verify system performance. With the 80K MLI system defined, the current effort has focused on experimentally defining the optimum insulation scheme for the 20K thermal shield. The SSC design specification requires that radiant heat transfer be limited to 0.093 W/m 2 at an insulating vacuum of 10 -6 torr

Thermal Transmittance and the Embodied Energy of Timber Frame Lightweight Walls Insulated with Straw and Reed

Science.gov (United States)

Miljan, M.; Miljan, J.

2015-11-01

Sustainable energy use has become topical in the whole world. Energy gives us comfort we are used to. EU and national regulations determine energy efficiency of the buildings. This is one side of the problem - energy efficiency of houses during exploitation. But the other side is primary energy content of used materials and more rational use of resources during the whole life cycle of a building. The latter value constitutes about 8 - 20% from the whole energy content. Calculations of energy efficiency of materials lead us to energy efficiency of insulation materials and to comparison of natural and industrial materials taking into account their thermal conductivity as well as their primary energy content. Case study of the test house (built in 2012) insulated with straw bales gave the result that thermal transmittance of investigated straw bale walls was according to the minimum energy efficiency requirements set in Estonia U = 0.12 - 0.22 W/m2K (for walls).

Exterior Insulation Implications for Heating and Cooling Systems in Cold Climates

Energy Technology Data Exchange (ETDEWEB)

Herk, Anastasia [IBACOS Inc., Pittsburgh, PA (United States); Poerschke, Andrew [IBACOS Inc., Pittsburgh, PA (United States)

2015-04-09

The New York State Energy Research and Development Authority (NYSERDA) is interested in finding cost-effective solutions for deep energy retrofits (DERs) related to exterior wall insulation in a cold climate, with targets of 50% peak load reduction and 50% space conditioning energy savings. The U.S. Department of Energy Building America team, IBACOS, in collaboration with GreenHomes America, Inc. (GHA), was contracted by NYSERDA to research exterior wall insulation solutions. In addition to exterior wall insulation, the strategies included energy upgrades where needed in the attic, mechanical and ventilation systems, basement, band joist, walls, and floors. Under Building America, IBACOS is studying the impact of a “thermal enclosure” DER on the sizing of the space conditioning system and the occupant comfort if the thermal capacity of the heating and cooling system is dramatically downsized without any change in the existing heating and cooling distribution system (e.g., size, tightness and supply outlet configurations).

Exterior Insulation Implications for Heating and Cooling Systems in Cold Climates

Energy Technology Data Exchange (ETDEWEB)

Herk, Anastasia; Poerschke, Andrew

2015-04-01

The New York State Energy Research and Development Authority (NYSERDA) is interested in finding cost-effective solutions for deep energy retrofits (DERs) related to exterior wall insulation in a cold climate, with targets of 50% peak load reduction and 50% space conditioning energy savings. The U.S. Department of Energy Building America team, IBACOS, in collaboration with GreenHomes America, Inc. (GHA), was contracted by NYSERDA to research exterior wall insulation solutions. In addition to exterior wall insulation, the strategies included energy upgrades where needed in the attic, mechanical and ventilation systems, basement, band joist, walls, and floors. Under Building America, IBACOS is studying the impact of a “thermal enclosure” DER on the sizing of the space conditioning system and the occupant comfort if the thermal capacity of the heating and cooling system is dramatically downsized without any change in the existing heating and cooling distribution system (e.g., size, tightness and supply outlet configurations).

The Wick-Concept for Thermal Insulation of Cold Piping

DEFF Research Database (Denmark)

Koverdynsky, Vit; Korsgaard, Vagn; Rode, Carsten

2006-01-01

the wick-concept in either of two variations: the self-drying or the self-sealing system. Experiments have been carried out using different variations of the two systems to investigate the conditions for exploiting the drying capabilities of the systems, and the results are presented. The results show......The wick-concept for thermal insulation of cold piping is based on capillary suction of a fiber fabric to remove excess water from the pipe surface by transporting it to the outer surface of the insulation. From the surface of the insulation jacket, the water will evaporate to the ambient air....... This will prevent long-term accumulation of moisture in the insulation material. The wick keeps the hydrophobic insulation dry, allowing it to maintain its thermal performance. The liquid moisture is kept only in the wick fabric. This article presents the principle of operation of cold pipe insulation using...

A Facile Approach to Evaluate Thermal Insulation Performance of Paper Cups

Directory of Open Access Journals (Sweden)

Yudi Kuang

2015-01-01

Full Text Available Paper cups are ubiquitous in daily life for serving water, soup, coffee, tea, and milk due to their convenience, biodegradability, recyclability, and sustainability. The thermal insulation performance of paper cups is of significance because they are used to supply hot food or drinks. Using an effective thermal conductivity to accurately evaluate the thermal insulation performance of paper cups is complex due to the inclusion of complicated components and a multilayer structure. Moreover, an effective thermal conductivity is unsuitable for evaluating thermal insulation performance of paper cups in the case of fluctuating temperature. In this work, we propose a facile approach to precisely analyze the thermal insulation performance of paper cups in a particular range of temperature by using an evaluation model based on the MISO (Multiple-Input Single-Output technical theory, which includes a characterization parameter (temperature factor and a measurement apparatus. A series of experiments was conducted according to this evaluation model, and the results show that this evaluation model enables accurate characterization of the thermal insulation performance of paper cups and provides an efficient theoretical basis for selecting paper materials for paper cups.

Large displacement spring-like electro-mechanical thermal actuators with insulator constraint beams

Science.gov (United States)

Luo, J. K.; Fu, Y. Q.; Flewitt, A. J.; Spearing, S. M.; Fleck, N. A.; Milne, W. I.

2005-07-01

A number of in-plane spring-like micro-electro-thermal-actuators with large displacements were proposed. The devices take the advantage of the large difference in the thermal expansion coefficients between the conductive arms and the insulator clamping beams. The constraint beams in one type (the spring) of these devices are horizontally positioned to restrict the expansion of the active arms in the x-direction, and to produce a displacement in the y-direction only. In other two types of actuators (the deflector and the contractor), the constraint beams are positioned parallel to the active arms. When the constraint beams are on the inside of the active arms, the actuator produces an outward deflection in the y-direction. When they are on the outside of the active arms, the actuator produces an inward contraction. Analytical model and finite element analysis were used to simulate the performances. It showed that at a constant temperature, analytical model is sufficient to predict the displacement of these devices. The displacements are all proportional to the temperature and the number of the chevron sections. A two-mask process is under development to fabricate these devices, using Si3N4 as the insulator beams, and electroplated Ni as the conductive beams.

Effect of Nanoclay on Mechanical Properties and Ablation Behavior of a Nitrile-Based Heat Insulator

Directory of Open Access Journals (Sweden)

Fatemeh Arabgol

2013-02-01

Full Text Available Thermal insulation of rocket motor chamber is one of the most important functions of elastomeric ablative material. Combustion of solid rocket motor propellant produces turbulent media containing gases with a velocity more than 1000 m/s, temperature and pressure more than 3000°C and 10 MPa, respectively,which destroys all metallic alloys. Elastomeric nanocomposite heat insulators are more attractive subjects in comparison to their non-elastomeric counterparts, due to their excellent thermal stresses and larger deformation bearing capacity. Nitrile rubber with high thermal properties is a proper candidate in such applications. Development in ablation performance of these heat shields is considered as an important challenge nowadays. A few works have been recently carried out using organoclay to enhancethe ablation and mechanical properties of heat insulators. In this work, an elastomeric heat insulator with superior ablative and mechanical properties was presented using nanotechnology. The results showed that an elastomeric nanocomposite heat insulator containing 15 wt% organoclay exhibits superior characteristics compared to its composite counterpart such as: 46% more tensile strength, 60% more elongationat-break, 1.7 times higher modulus (at 100% strain, 62% higher “insulating index number” and 36% lower mass ablation and erosion rates under a standard test with a heat flux of 2500 kW/m2 for 15 s.

Standard Practice for Evaluating Thermal Insulation Materials for Use in Solar Collectors

CERN Document Server

American Society for Testing and Materials. Philadelphia

1994-01-01

1.1 This practice sets forth a testing methodology for evaluating the properties of thermal insulation materials to be used in solar collectors with concentration ratios of less than 10. Tests are given herein to evaluate the pH, surface burning characteristics, moisture adsorption, water absorption, thermal resistance, linear shrinkage (or expansion), hot surface performance, and accelerated aging. This practice provides a test for surface burning characteristics but does not provide a methodology for determining combustibility performance of thermal insulation materials. 1.2 The tests shall apply to blanket, rigid board, loose-fill, and foam thermal insulation materials used in solar collectors. Other thermal insulation materials shall be tested in accordance with the provisions set forth herein and should not be excluded from consideration. 1.3 The assumption is made that elevated temperature, moisture, and applied stresses are the primary factors contributing to the degradation of thermal insulation mat...

Thermal transport across metal–insulator interface via electron–phonon interaction

International Nuclear Information System (INIS)

Zhang, Lifa; Wang, Jian-Sheng; Li, Baowen; Lü, Jing-Tao

2013-01-01

The thermal transport across a metal–insulator interface can be characterized by electron–phonon interaction through which an electron lead is coupled to a phonon lead if phonon–phonon coupling at the interface is very weak. We investigate the thermal conductance and rectification between the electron part and the phonon part using the nonequilibrium Green’s function method. It is found that the thermal conductance has a nonmonotonic behavior as a function of average temperature or the coupling strength between the phonon leads in the metal part and the insulator part. The metal–insulator interface shows a clear thermal rectification effect, which can be reversed by a change in average temperature or the electron–phonon coupling. (paper)

Sprayable Thermal Insulation for Cryogenic Tanks, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — The Sprayable Thermal Insulation for Cryogenic Tanks (STICT) is a thermal management system applied by either an automated or manual spraying process with less...

Influence of light masonry mortar on the thermal insulation of a solid brick wall

Energy Technology Data Exchange (ETDEWEB)

Kupke, C

1980-12-01

For calculations of the thermal insulation of structural components according to DIN 4108 and to the Thermal Insulation Ordinance, characteristic data of thermal conductivity are used which are contained in DIN 4108 and in the Bundesanzeiger in Supplements to the publication of material characteristics for the calculation of thermal insulation according to the Thermal Insulation Ordinance. For masonry, this value is equivalent to the thermal conductivity of the bricks, including mortar joints. The mortar considered is standard mortar, group II, according to DIN 1053. In the last few years, in order to improve the thermal insulation, mortars of low thermal conductivity and low volume weight - so-called light masonry mortars - have been used to an increasing extent. The improvement in thermal conductivity as compared with standard mortar is referred to as ..delta..lambda; it depends mostly on the thermal conductivity of the light mortar and the bricks. In the article, the laws governing the influence of light masonry mortar on the thermal insulation of masonry of solid bricks and solid blocks are reviewed.

Determination of Optimum Thermal Insulation Thicknesses for External Walls Considering the Heating, Cooling and Annual Energy Requirement

Directory of Open Access Journals (Sweden)

Ömer KAYNAKLI

2016-06-01

Full Text Available In this study, optimization of thermal insulation thickness applied to the external walls of buildings has been carried out comparatively based on the seasonal (space-heating and cooling and the annual energy requirements considering solar radiation effect. This study has been performed for four degree-day regions of Turkey, namely, Iskenderun (in the first region, Istanbul (in the second region, Ankara (in the third region and Ardahan (in the fourth region. By determining the sol-air temperatures for each region and maximizing the present worth value of seasonal and annual energy savings, the optimum thermal insulation thicknesses have been calculated. The effects of solar radiation on heating-cooling energy requirements, the variation of optimum insulation thicknesses and payback periods with respect to degree-day regions, the differences between the analyses based on seasonal and annual have been presented in tabular and graphical form.

A protocol for lifetime energy and environmental impact assessment of building insulation materials

International Nuclear Information System (INIS)

Shrestha, Som S.; Biswas, Kaushik; Desjarlais, Andre O.

2014-01-01

This article describes a proposed protocol that is intended to provide a comprehensive list of factors to be considered in evaluating the direct and indirect environmental impacts of building insulation materials, as well as detailed descriptions of standardized calculation methodologies to determine those impacts. The energy and environmental impacts of insulation materials can generally be divided into two categories: (1) direct impact due to the embodied energy of the insulation materials and other factors and (2) indirect or environmental impacts avoided as a result of reduced building energy use due to addition of insulation. Standards and product category rules exist, which provide guidelines about the life cycle assessment (LCA) of materials, including building insulation products. However, critical reviews have suggested that these standards fail to provide complete guidance to LCA studies and suffer from ambiguities regarding the determination of the environmental impacts of building insulation and other products. The focus of the assessment protocol described here is to identify all factors that contribute to the total energy and environmental impacts of different building insulation products and, more importantly, provide standardized determination methods that will allow comparison of different insulation material types. Further, the intent is not to replace current LCA standards but to provide a well-defined, easy-to-use comparison method for insulation materials using existing LCA guidelines. - Highlights: • We proposed a protocol to evaluate the environmental impacts of insulation materials. • The protocol considers all life cycle stages of an insulation material. • Both the direct environmental impacts and the indirect impacts are defined. • Standardized calculation methods for the ‘avoided operational energy’ is defined. • Standardized calculation methods for the ‘avoided environmental impact’ is defined

Evaluating in situ thermal transmittance of green buildings masonries—A case study

Directory of Open Access Journals (Sweden)

Francesco Asdrubali

2014-01-01

The paper presents the results of a measurement campaign of in situ thermal transmittance, performed in some buildings in the Umbria Region (Italy, designed implementing bio-architecture solutions. The analyzed walls were previously monitored with thermographic surveys in order to assess the correct application of the sensors. Results of the investigation show that in situ thermal transmittance measurements and theoretical calculated U-value are not in perfect agreement. The mismatch becomes important for monolithic structures such as walls made of thermal blocks without insulating layers.

State of the art on historic building insulation materials and retrofit strategies

DEFF Research Database (Denmark)

Blumberga, Andra; Kass, Kristaps; Kamendere, Edite

2016-01-01

This report provides an analysis and evaluation of a state-of-the-art of internal insulation materials and methods for application in historic buildings, and review on methods, tools and guidelines used as decision making tools for implementation of internal insulation in historic buildings. Hist...

Improving the energy performance of historic buildings with architectural and cultural values

DEFF Research Database (Denmark)

Hansen, Ernst Jan de Place

2017-01-01

The thermal performance of solid walls of historic buildings can be improved by external or internal insulation. External insulation is preferred from a technical perspective, but is often disregarded as many such buildings have architectural or cultural values leaving internal insulation.......g. improvement of thermal indoor climate. The paper discusses different motivating factors for improving the thermal performance of solid walls in historic buildings with architectural and cultural values. It is argued that internal insulation, provided that it can be done without resulting in critical moisture...... as the only possible solution. As internal insulation is considered a risky way of improving the thermal performance from a moisture perspective, technically feasible solutions are needed. Further, other arguments than energy saving could convince a building owner to carry out internal insulation, e...

Cladding Attachment Over Thick Exterior Insulating Sheathing

Energy Technology Data Exchange (ETDEWEB)

Baker, P. [Building Science Corporation, Somerville, MA (United States); Eng, P. [Building Science Corporation, Somerville, MA (United States); Lepage, R. [Building Science Corporation, Somerville, MA (United States)

2014-01-01

The addition of insulation to the exterior of buildings is an effective means of increasing the thermal resistance of both wood framed walls as well as mass masonry wall assemblies. For thick layers of exterior insulation (levels greater than 1.5 inches), the use of wood furring strips attached through the insulation back to the structure has been used by many contractors and designers as a means to provide a convenient cladding attachment location (Straube and Smegal 2009, Pettit 2009, Joyce 2009, Ueno 2010). The research presented in this report is intended to help develop a better understanding of the system mechanics involved and the potential for environmental exposure induced movement between the furring strip and the framing. BSC sought to address the following research questions: 1. What are the relative roles of the mechanisms and the magnitudes of the force that influence the vertical displacement resistance of the system? 2. Can the capacity at a specified deflection be reliably calculated using mechanics based equations? 3. What are the impacts of environmental exposure on the vertical displacement of furring strips attached directly through insulation back to a wood structure?

Design Considerations for Thermally Insulating Structural Sandwich Panels for Hypersonic Vehicles

Science.gov (United States)

Blosser, Max L.

2016-01-01

Simplified thermal/structural sizing equations were derived for the in-plane loading of a thermally insulating structural sandwich panel. Equations were developed for the strain in the inner and outer face sheets of a sandwich subjected to uniaxial mechanical loads and differences in face sheet temperatures. Simple equations describing situations with no viable solution were developed. Key design parameters, material properties, and design principles are identified. A numerical example illustrates using the equations for a preliminary feasibility assessment of various material combinations and an initial sizing for minimum mass of a sandwich panel.

A Network Model for the Effective Thermal Conductivity of Rigid Fibrous Refractory Insulations

Science.gov (United States)

Marschall, Jochen; Cooper, D. M. (Technical Monitor)

1995-01-01

A procedure is described for computing the effective thermal conductivity of a rigid fibrous refractory insulation. The insulation is modeled as a 3-dimensional Cartesian network of thermal conductance. The values and volume distributions of the conductance are assigned to reflect the physical properties of the insulation, its constituent fibers, and any permeating gas. The effective thermal conductivity is computed by considering the simultaneous energy transport by solid conduction, gas conduction and radiation through a cubic volume of model insulation; thus the coupling between heat transfer modes is retained (within the simplifications inherent to the model), rather than suppressed by treating these heat transfer modes as independent. The model takes into account insulation composition, density and fiber anisotropy, as well as the geometric and material properties of the constituent fibers. A relatively good agreement, between calculated and experimentally derived thermal conductivity values, is obtained for a variety of rigid fibrous insulations.

RESEARCHES REGARDING USE OF TEXTILE MATERIALS FOR THERMAL INSULATION AT NEGATIVE TEMPERATURES

Directory of Open Access Journals (Sweden)

IOSUB Andrei

2014-05-01

Full Text Available Using thermal insulation in negative temperature acts to reduce heat flow to the cooled space or to objects that have a temperature below ambient temperature. To achieve economic operation of the space to be cooled insulation thickness and quality is an important factor. In this article we want to compare three products used in thermal insulation at negative temperatures: expanded polystyrene, non-woven and wool coats. The materials will be tested with a mechanical vapor compression refrigerator capable of producing temperatures in the range +4 .. -35 ° C, managed by a programmer Dixel capable of recording values between +40. .. -60 °C. Refrigeration insulation enclosure was made with 100 mm expanded polystyrene. On one side of the enclosure will be a cut of 250 * 250 mm, chosen in a central position where the material will be introduced to be tested. The dimensions of the samples are 250 * 250 * 60 mm. To check the insulation properties of materials it will be used a temperature logger capable of recording with two probes temperatures between +125...-40° C. One of the probes will be inserted inside the refrigerator and the second probe will be positioned to the outside of the test material adhered to an aluminum plate, in order to read a average temperature. The difference in thickness of the insulation shall be filled with non-woven material. Hardening the assembly will be made using a 6 mm thick OSB board. The materials will be tested in an identical ambient temperature and humidity.

Effect of the insulation materials filling on the thermal performance of sintered hollow bricks under the air-conditioning intermittent operation

Directory of Open Access Journals (Sweden)

Chaoping Hou

2018-06-01

Full Text Available Wall insulation performance is an important factor affecting building energy consumption and indoor comfortable level. This study proposes that the insulation materials are filled into the cavities of the sintered hollow brick to replace the single insulation layer. The physical models of typical walls were built by the hollow bricks filled with expanding polystyrene board (EPS in cavities and wall thermal performance is numerically analyzed by the Finite Volume Method under air-conditioning intermittent operation, which conforms to the actual operation rules of air-conditioning. Results show that filling EPS in cavities is beneficial to improve the thermal performance of the bricks, and the larger the EPS filling ratio, the higher the thermal performance improvement. The EPS filling ratio increase has the higher sensitivity on inner surface heat flow under the low EPS filling ratio, and filling EPS in the external cavities is optimum with the decrement rate 5.92% higher than filling EPS in internal cavities for the EPS filling ratio of 20%, while filling EPS in internal and external cavities simultaneously is optimum with decrement rate 2.45%–6.87% higher than that with filling EPS in the internal cavities for the EPS filling ratio of 40%–80%. Keywords: Insulation filling ratio, Insulation filling location, Thermal performance, Sintered hollow bricks

CO2 Insulation for Thermal Control of the Mars Science Laboratory

Science.gov (United States)

Bhandari, Pradeep; Karlmann, Paul; Anderson, Kevin; Novak, Keith

2011-01-01

The National Aeronautics and Space Administration (NASA) is sending a large (>850 kg) rover as part of the Mars Science Laboratory (MSL) mission to Mars in 2011. The rover's primary power source is a Multi-Mission Radioisotope Thermoelectric Generator (MMRTG) that generates roughly 2000 W of heat, which is converted to approximately 110 W of electrical power for use by the rover electronics, science instruments, and mechanism-actuators. The large rover size and extreme thermal environments (cold and hot) for which the rover is designed for led to a sophisticated thermal control system to keep it within allowable temperature limits. The pre-existing Martian atmosphere of low thermal conductivity CO2 gas (8 Torr) is used to thermally protect the rover and its components from the extremely cold Martian environment (temperatures as low as -130 deg C). Conventional vacuum based insulation like Multi Layer Insulation (MLI) is not effective in a gaseous atmosphere, so engineered gaps between the warm rover internal components and the cold rover external structure were employed to implement this thermal isolation. Large gaps would lead to more thermal isolation, but would also require more of the precious volume available within the rover. Therefore, a balance of the degree of thermal isolation achieved vs. the volume of rover utilized is required to reach an acceptable design. The temperature differences between the controlled components and the rover structure vary from location to location so each gap has to be evaluated on a case-by-case basis to arrive at an optimal thickness. For every configuration and temperature difference, there is a critical thickness below which the heat transfer mechanism is dominated by simple gaseous thermal conduction. For larger gaps, the mechanism is dominated by natural convection. In general, convection leads to a poorer level of thermal isolation as compared to conduction. All these considerations play important roles in the

Thermal characteristic of insulation for optimum design of RI transport package

International Nuclear Information System (INIS)

Lee, J. C.; Bang, K. S.; Seo, K. S.

2002-01-01

A package to transport the high level radioactive materials in required to withstand the hypothetical accident conditions as well as normal transport conditions according to IAEA and domestic regulations. The regulations require that the package should maintain the shielding, thermal and structural integrities to release no radioactive material. Thermal characteristics of insulations were evaluated and optimum insulation thickness was deduced for RI transport package. The package has a maximum capacity of 600 Curies for Ir-192 sealed source. The insulation thickness was decided with 10 mm of polyurethane form to maintain the thermal safety under fire accident condition. Thermal analysis was carried out for RI transport package, and it was shown that the thermal integrity of the package was maintained. The results obtained this study will be applied to a basic data for design of RI transport cask

A metric for characterizing the effectiveness of thermal mass in building materials

International Nuclear Information System (INIS)

Talyor, Robert A.; Miner, Mark

2014-01-01

Highlights: • Proposes a metric for interior thermal mass materials (floors, walls, counters). • Simple, yet effective, metric composed of easily calculated ‘local’ and ‘global’ variables. • Like Energy Star, the proposed metric gives a single number to aid consumer choice. • The metric is calculated and compared for selected, readily available data. • Drywall, concrete flooring, and wood paneling are quite effective thermal mass. - Abstract: Building energy use represents approximately 25% of the average total global energy consumption (for both residential and commercial buildings). Heating, ventilation, and air conditioning (HVAC) – in most climates – embodies the single largest draw inside our buildings. In many countries around the world a concerted effort is being made towards retrofitting existing buildings to improve energy efficiency. Better windows, insulation, and ducting can make drastic differences in the energy consumption of a building HVAC system. Even with these improvements, HVAC systems are still required to compensate for daily and seasonal temperature swings of the surrounding environment. Thermal mass inside the thermal envelope can help to alleviate these swings. While it is possible to add specialty thermal mass products to buildings for this purpose, commercial uptake of these products is low. Common building interior building materials (e.g. flooring, walls, countertops) are often overlooked as thermal mass products, but herein we propose and analyze non-dimensional metrics for the ‘benefit’ of selected commonly available products. It was found that location-specific variables (climate, electricity price, material price, insolation) can have more than an order of magnitude influence in the calculated metrics for the same building material. Overall, this paper provides guidance on the most significant contributors to indoor thermal mass, and presents a builder- and consumer-friendly metric to inform decisions about

Technology of Double Thermal Insulation for the Repair and Energy Optimization of Existing Thermal Insulation Composite Systems

Science.gov (United States)

Belániová, Barbora; Antošová, Naďa

2017-06-01

The theme of improvement thermal proprieties of external cladding according to the New EU Directive is still a hot topic, which needs to be answered necessarily till December 2020. Maintenance and repair of existing ETICS became to also an actual open theme in search solutions for existing constructions. The aim of the research in this review is to analyze influence of layers the alternative thermal materials in technology "double thermal insulation". Humidity and temperature conditions will be further examined in connection with the development and colonization of microorganisms on surface construction.

External insulation with cellular plastic materials

DEFF Research Database (Denmark)

Sørensen, Lars Schiøtt; Nielsen, Anker

2014-01-01

External thermal insulation composite systems (ETICS) can be used as extra insulation of existing buildings. The system can be made of cellular plastic materials or mineral wool. There is a European Technical guideline, ETAG 004, that describe the tests that shall be conducted on such systems....... This paper gives a comparison of systems with mineral wool and cellular plastic, based on experience from practice and literature. It is important to look at the details in the system and at long time stability of the properties such as thermal insulation, moisture and fire. Investigation of fire properties...

Thermal performance measurement and application of a multilayer insulator for emergency architecture

International Nuclear Information System (INIS)

Salvalai, Graziano; Imperadori, Marco; Scaccabarozzi, Diego; Pusceddu, Cristina

2015-01-01

Lightness coupled with a quick assembly method is crucial for emergency architecture in post-disaster area where accessibility and action time play a huge barer to rescue people. In this prospective, the following work analyses the potentiality (technological and thermal performances) of multilayer insulator for a new shelter envelope able to provide superior thermal comfort for the users. The thermal characteristics are derived experimentally by means of a guard ring apparatus under different working temperatures. Tests are performed on the multilayer insulator itself and on a composite structure, made of the multilayer insulator and two air gaps wrapped by a polyester cover, which is the core of a new lightweight emergency architecture. Experimental results show good agreement with literature data, providing a thermal conductivity and transmittance of about 0.04 W/(m °C) and 1.6 W/(m 2  °C) for the tested multilayer. The composite structure called Thermo Reflective Multilayer System (TRMS) shows better insulation performances, providing a thermal transmittance set to 0.85 W/(m 2  °C). A thermal model of an emergency tent based on the new insulating structure (TRMS) has been developed and its thermal performances have been compared with those of a UNHCR traditional emergency shelter. The shelter model was simulated (Trnsys v.17 environment) in the winter season considering the climate of Belgrade and using only the casual gains from occupant and solar radiation through opaque wall. Numerical simulations evidenced that the new insulating composite envelope reduces required heating load of about two and four times with respect to the traditional insulation. The study sets a starting point to develop a lightweight emergency architecture made with a combination between multilayer, air, polyester and vulcanized rubber. - Highlights: • Multilayer insulator tested by means of a guard ring apparatus. • Thermo reflective multilayer system (TRMS) development

Thermal insulation of fuel elements

International Nuclear Information System (INIS)

Dubrovcak, P.; Pec, V.; Pitonak, J.

1978-01-01

The claim of the invention concerns thermal insulation of fuel elements heated for measurement of uranium fuel physical properties. For this, layers of aluminium film and of glass fibre are wound onto the inner tube of the element cladding. The space between the inner and the outer tubes is evacuated and the tubes are spaced using spacer wires. (M.S.)

Preliminary data evaluation for thermal insulation characterization testing

International Nuclear Information System (INIS)

DeClue, J.F.; Moses, S.D.; Tollefson, D.A.

1991-01-01

The purpose of Thermal Insulation Characterization Testing is to provide physical data to support certain assumptions and calculational techniques used in the criticality safety calculations in Section 6 of the Safety Analysis Reports for Packaging (SARPs) for drum-type packaging for Department of Energy's (DOE) Oak Ridge Y-12 Plant, managed by Martin Marietta Energy Systems, Inc. Results of preliminary data evaluation regarding the fire-test condition reveal that realistic weight loss consideration and residual material characterization in developing calculational models for the hypothetical accident condition is necessary in order to prevent placement of unduly conservative restrictions on shipping requirements as a result of overly conservative modeling. This is particularly important for fast systems. Determination of the geometric arrangement of residual material is of secondary importance. Both the methodology used to determine the minimum thermal insulation mass remaining after the fire test and the treatment of the thermal insulation in the criticality safety calculational models requires additional evaluation. Specific testing to be conducted will provide experimental data with which to validate the mass estimates and calculational modeling techniques for extrapolation to generic drum-type containers

Safety distance for preventing hot particle ignition of building insulation materials

OpenAIRE

Jiayun Song; Supan Wang; Haixiang Chen

2014-01-01

Trajectories of flying hot particles were predicted in this work, and the temperatures during the movement were also calculated. Once the particle temperature decreased to the critical temperature for a hot particle to ignite building insulation materials, which was predicted by hot-spot ignition theory, the distance particle traveled was determined as the minimum safety distance for preventing the ignition of building insulation materials by hot particles. The results showed that for sphere ...

Thermal and Economic Analysis of Renovation Strategies for a Historic Building in Mediterranean Area

Directory of Open Access Journals (Sweden)

Simona Cirami

2017-07-01

Full Text Available Around 30% of the European building stock was built before 1950, when no regulations about energy efficiency were in force. Since only a small part of them has been renovated by now, the energy performance of this building stock is on average quite poor, resulting in a significant impact on the energy balance of European countries, as confirmed by data published by ISTAT (Italian National Statistical Institute. However, energy retrofit in historic edifices is a quite demanding issue as any intervention must take into account the need to preserve existing building materials and appearances while also allowing reversibility and low invasiveness. As an example, in these buildings it is not possible to apply an ETICS (External Thermal Insulation Composite System, since this would alter the historic and architectural value of the façade. On the other hand, internal insulation would have the drawback of reducing the net useful floor area, which also implies a loss of economic value. Moreover, internal insulation may induce overheating risks and mold formation. In this paper, all these issues are investigated with reference to an existing historic building located in southern Italy, showing that a retrofit strategy aimed at energy savings and cost-effectiveness is still possible if suitable materials and solutions are adopted.

Thermal support elements (TTE) made of high-tensile fibre-reinforced material and integrated vacuum-insulation panels (VIP) - Final report; Thermotragelemente (TTE) aus hochfestem Faserverbundstoff und integrierten Vakuumisolationspaneelen (VIP) - Schlussbericht

Energy Technology Data Exchange (ETDEWEB)

Motavalli, M.; Ghazi Wakili, K.; Gsell, D.; Herwig, A.

2008-07-01

In this project, the static and thermal characteristics of the balcony connection element TTE (load carrying thermo-element) of the Hitek Construction Company AG were investigated. The TTE is an innovative element, which minimises thermal bridges that always exist in the vicinity of balcony connections. The concept of the element relies of the ability of fibre reinforced composites with superior thermal and mechanical characteristics to transfer the high mechanical loads from the balcony, through the layer of insulation, to the building. From a mechanical point-of-view, only very limited use of fibre reinforced composites has been seen for this type of construction application, therefore necessitating a detailed investigation of the element. In a first step, component tests of the individual load carrying elements were carried out, in which the elements showed an entirely satisfactory short-term behaviour. Furthermore, several assembly tests were carried out whereby parts of the balcony were reproduced, loaded and observed over longer term. During the investigations it was seen that very high stresses occur in the compression zone of the concrete deck and that the element must be modified in the future. From a thermal point-of-view, the TTE element offers a considerable improvement as compared with concrete decks without a thermal discontinuity. The thermal properties of the TTE element can be considered similar to or slightly better than other thermally discontinuous systems with the same load carrying capacity. This is understandable, since a thicker insulating layer with a thermal resistance of 2.5 m{sup 2} K/W was partially replaced through a thinner, yet more efficient insulation with a thermal resistance of 1.9 m{sup 2} K/W. Moreover, the glass fibre reinforced polymer has a larger thermal resistance than steel. The results obtained from the mechanical and thermal tests point to the need for further optimisation of the TTE element. It has been seen, however

Design of the Building Envelope: A Novel Multi-Objective Approach for the Optimization of Energy Performance and Thermal Comfort

Directory of Open Access Journals (Sweden)

Fabrizio Ascione

2015-08-01

Full Text Available According to the increasing worldwide attention to energy and the environmental performance of the building sector, building energy demand should be minimized by considering all energy uses. In this regard, the development of building components characterized by proper values of thermal transmittance, thermal capacity, and radiative properties is a key strategy to reduce the annual energy need for the microclimatic control. However, the design of the thermal characteristics of the building envelope is an arduous task, especially in temperate climates where the energy demands for space heating and cooling are balanced. This study presents a novel methodology for optimizing the thermo-physical properties of the building envelope and its coatings, in terms of thermal resistance, capacity, and radiative characteristics of exposed surfaces. A multi-objective approach is adopted in order to optimize energy performance and thermal comfort. The optimization problem is solved by means of a Genetic Algorithm implemented in MATLAB®, which is coupled with EnergyPlus for performing dynamic energy simulations. For demonstration, the methodology is applied to a residential building for two different Mediterranean climates: Naples and Istanbul. The results show that for Naples, because of the higher incidence of cooling demand, cool external coatings imply significant energy savings, whereas the insulation of walls should be high but not excessive (no more than 13–14 cm. The importance of high-reflective coating is clear also in colder Mediterranean climates, like Istanbul, although the optimal thicknesses of thermal insulation are higher (around 16–18 cm. In both climates, the thermal envelope should have a significant mass, obtainable by adopting dense and/or thick masonry layers. Globally, a careful design of the thermal envelope is always necessary in order to achieve high-efficiency buildings.

The roles of thermal insulation and heat storage in the energy performance of the wall materials: a simulation study.

Science.gov (United States)

Long, Linshuang; Ye, Hong

2016-04-07

A high-performance envelope is the prerequisite and foundation to a zero energy building. The thermal conductivity and volumetric heat capacity of a wall are two thermophysical properties that strongly influence the energy performance. Although many case studies have been performed, the results failed to give a big picture of the roles of these properties in the energy performance of an active building. In this work, a traversal study on the energy performance of a standard room with all potential wall materials was performed for the first time. It was revealed that both heat storage materials and insulation materials are suitable for external walls. However, the importances of those materials are distinct in different situations: the heat storage plays a primary role when the thermal conductivity of the material is relatively high, but the effect of the thermal insulation is dominant when the conductivity is relatively low. Regarding internal walls, they are less significant to the energy performance than the external ones, and they need exclusively the heat storage materials with a high thermal conductivity. These requirements for materials are consistent under various climate conditions. This study may provide a roadmap for the material scientists interested in developing high-performance wall materials.

Investigation of cryogenic irradiation influence on mechanical and physical properties of ITER magnetic system insulation materials

International Nuclear Information System (INIS)

Kozlov, A.V.; Scherbacov, E.N.; Dudchenko, N.A.; Shihalev, V.S.; Bedin, V.V.; Paltusov, N.A.; Korsunskiy, V.E.

1998-01-01

A set of methods of cryogenic irradiation influence test on mechanical and physical properties of insulation of ITER magnetic system are presented in this paper. Investigations are carried out without intermediate warming up of samples. A Russian insulating composite material was irradiated in the IVV-2M reactor. The ratio of energy absorbed by insulation materials from neutron irradiation to that from gamma irradiation can be varied from ∝(25:75)% to ∝(50:50)% in the reactor. The test results on the thermal expansion, thermal conductivity and gas evolution of the above material are presented. It was shown, that cryogenic irradiation up to the fluence ∝2 x 10 22 n/m 2 (E ≥ 0.1 MeV) leads to 0.27% linear size changes along layers of fiber-glass, the thermal conductivity coefficient is decreased on 15% at 100 k in perpendicular direction to fiber-glass plane, and thermal coefficient of linear expansion (TCLE) has anomalous temperature dependence. (orig.)

Economic and Environmental Optimization of an Airport Terminal Building’s Wall and Roof Insulation

Directory of Open Access Journals (Sweden)

Mehmet Kadri Akyüz

2017-10-01

Full Text Available HVAC systems use the largest share of energy consumption in airport terminal buildings. Thus, the efficiency of the HVAC system and the performance of the building envelope have great importance in reducing the energy used for heating and cooling purposes. In this study, the application of thermal insulation on the walls and roof of the Hasan Polatkan Airport terminal building was investigated from energy, environment and cost aspects. This study determined the optimum insulation thickness and assessed its effects on environmental performance based on energy flows. Environmental payback periods were calculated depending on the optimum insulation thickness. The life cycle assessment (LCA method was used to assess whether the decrease in energy consumption after applying the insulation balanced the environmental effects during the period between the production and application of the thermal insulation material. The global warming potential (GWP based on IPCC100, and the effects on human health (HH, the ecosystem and natural resources were evaluated according to the ReCiPe method. LCA results were obtained by processing data taken from ecoinvent 3 database present in the Sima Pro 8.3.0.0 software. Applying thermal insulation on the walls and roof of the terminal building was found to decrease heat loss by 48% and 56%, respectively. In addition, the analyses showed that the environmental payback periods for the thermal insulation were shorter than the economic payback periods.

Improved thermal monitoring of rotating machine insulation

International Nuclear Information System (INIS)

Stone, G.C.; Sedding, H.G.; Bernstein, B.S.

1991-01-01

Aging of motor and generator insulation is most often induced as a result of operation at high temperatures. In spite of this knowledge, stator and rotor temperatures are only crudely monitored in existing machines. In EPRI project RP2577-1, three new means of detecting machine temperatures were successfully developed. Two of the techniques, the Electronic Rotor Temperature Sensor and the Passive Rotor Temperature Sensor, were specifically developed to give point temperature readings on turbine generator rotor windings. The Insulation Sniffer allows operators to determine when any electrical insulation in a motor is overheating. Another electronic device, called the Thermal Life Indicator, helps operators and maintenance personnel determine how accumulated operation has affected the remaining life of the insulation in rotating machines. These new devices permit nuclear station operators to avoid hazardous operating conditions and will help to determine priorities for maintenance and plant life extension programs

Cryogenic foam insulation: Abstracted publications

Science.gov (United States)

Williamson, F. R.

1977-01-01

A group of documents were chosen and abstracted which contain information on the properties of foam materials and on the use of foams as thermal insulation at cryogenic temperatures. The properties include thermal properties, mechanical properties, and compatibility properties with oxygen and other cryogenic fluids. Uses of foams include applications as thermal insulation for spacecraft propellant tanks, and for liquefied natural gas storage tanks and pipelines.

Thermal paint production: the techno-economic evaluation of muscovite as insulating additive.

Directory of Open Access Journals (Sweden)

Gabriela Fernandes Ribas

2016-09-01

Full Text Available Muscovite is known by its thermal and electrical insulating properties. Based on this, it was hypothesized that its addition on paints should increase the thermal resistance. The use of muscovite as mineral insulating is pointed out as advantageous due to its low cost compared to other materials used for this purpose, such as the ceramic microsphere. The use of a low cost material could open the access to the medium and low income families, implying two aspects: the life quality increase by thermal comfort and the increase of energy saving. Thus, this part of the population could open a new market to thermal paints. Aiming to contribute to this issue, this work evaluated the thermal insulation performance of commercial paints containing muscovite additions and determined the economic evaluation for its industrial production. The thermal paint was formulated by adding 10%, 20% and 40% of muscovite to the commercial paint. This was applied on steel reinforced mortar boards. Thermal insulation tests were carried out in bench scale using an adapted box. The economic evaluation of the industrial production of muscovite-based thermal paint was conducted, considering the Brazilian economic market in this activity. The results showed its ability as an insulating agent due to a reduction of 0.667 °C/mm board by the addition of 40% muscovite. The economic analysis also demonstrated the feasibility of the thermal paint industrial production. The payback is favorable to 5 years when compared to the Selic short-term lending rate, with 21.53% of internal rate return and a net present value of US$ 15,085.76.

Building America Case Study: Trade-Friendly Retrofit Insulated Panels for Existing Buildings, Albany, New York

Energy Technology Data Exchange (ETDEWEB)

2016-03-01

This project evaluated the effectiveness and affordability of integrating retrofit insulated panels into a re-siding project. The Partnership for Home Innovation (PHI) teamed with New York State Energy Research and Development Authority (NYSERDA), the Albany Housing Authority (AHA), and the New York State Weatherization Assistance Program (WAP) administered by Albany Community Action Partnership to demonstrate an energy retrofit and siding upgrade on a two-story, seven unit, multifamily building in Albany New York (CZ 5). The project focused on accomplishing three goals - doubling the existing wall thermal resistance (from approximately R-13 to a weighted average of R-27), reduction of building air leakage, and completion of the retrofit within a budget where the additional cost for upgrading wall's thermal resistance is equal to the cost of the standard re-siding effort (i.e., the total cost of the energy efficient re-siding scope of work is not more than double the cost of the standard re-siding effort). Lessons learned from the project strongly indicate that the retrofit panel technology can be installed using common installation practices and with minimal training. Other lessons learned include limitation on the use of standard air sealing materials during cold weather installations and the need to develop better installation guidance for trades working with the level of tolerances that may be present in the existing structure. This technology demonstration showed that exterior retrofit panels provide a viable and reasonable option for the siding trades to increase market opportunities and achieve synergistic benefits for aesthetic upgrades to a building's exterior.

Detection of insulation flaws and thermal bridges in insulated truck box panels

OpenAIRE

Lei, Lei; Bortolin, Alessandro; Bison, Paolo ©; Maldague, X.

2017-01-01

This paper focuses on the detection of defects and thermal bridges in insulated truck box panels, utilising infrared thermography. Unlike the traditional way in which passive thermography is applied, this research uses both heating and cooling methods in active thermography configurations. Lamp heating is used as the hot external stimulation, while a compressed air jet is applied as the cold external stimulation. A thermal camera captures the whole process. In addition, numerical simulations ...

Energy in buildings: Efficiency, renewables and storage

Science.gov (United States)

Koebel, Matthias M.

2017-07-01

This lecture summary provides a short but comprehensive overview on the "energy and buildings" topic. Buildings account for roughly 40% of the global energy demands. Thus, an increased adoption of existing and upcoming materials and solutions for the building sector represents an enormous potential to reduce building related energy demands and greenhouse gas emissions. The central question is how the building envelope (insulation, fenestration, construction style, solar control) affects building energy demands. Compared to conventional insulation materials, superinsulation materials such as vacuum insulation panels and silica aerogel achieve the same thermal performance with significantly thinner insulation layers. With low-emissivity coatings and appropriate filler gasses, double and triple glazing reduce thermal losses by up to an order of magnitude compared to old single pane windows, while vacuum insulation and aerogel filled glazing could reduce these even further. Electrochromic and other switchable glazing solutions maximize solar gains during wintertime and minimize illumination demands whilst avoiding overheating in summer. Upon integration of renewable energy systems into the building energy supply, buildings can become both producers and consumers of energy. Combined with dynamic user behavior, temporal variations in the production of renewable energy require appropriate storage solutions, both thermal and electrical, and the integration of buildings into smart grids and energy district networks. The combination of these measures allows a reduction of the existing building stock by roughly a factor of three —a promising, but cost intensive way, to prepare our buildings for the energy turnaround.

Simultaneous reconstruction of thermal degradation properties for anisotropic scattering fibrous insulation after high temperature thermal exposures

International Nuclear Information System (INIS)

Zhao, Shuyuan; Zhang, Wenjiao; He, Xiaodong; Li, Jianjun; Yao, Yongtao; Lin, Xiu

2015-01-01

To probe thermal degradation behavior of fibrous insulation for long-term service, an inverse analysis model was developed to simultaneously reconstruct thermal degradation properties of fibers after thermal exposures from the experimental thermal response data, by using the measured infrared spectral transmittance and X-ray phase analysis data as direct inputs. To take into account the possible influence of fibers degradation after thermal exposure on the conduction heat transfer, we introduced a new parameter in the thermal conductivity model. The effect of microstructures on the thermal degradation parameters was evaluated. It was found that after high temperature thermal exposure the decay rate of the radiation intensity passing through the material was weakened, and the probability of being scattered decreased during the photons traveling in the medium. The fibrous medium scattered more radiation into the forward directions. The shortened heat transfer path due to possible mechanical degradation, along with the enhancement of mean free path of phonon scattering as devitrification after severe heat treatment, made the coupled solid/gas thermal conductivities increase with the rise of heat treatment temperature. - Highlights: • A new model is developed to probe conductive and radiative properties degradation of fibers. • To characterize mechanical degradation, a new parameter is introduced in the model. • Thermal degradation properties are reconstructed from experiments by L–M algorithm. • The effect of microstructures on the thermal degradation parameters is evaluated. • The analysis provides a powerful tool to quantify thermal degradation of fiber medium

Thermal Properties of Algerian Diatomite, Study of the Possibility to Its Use in the Thermal Insulation

Science.gov (United States)

Hamdi, Boualem; Hamdi, Safia

The chemical and physical properties of a Algerian diatomite were given before and after heat treatment and chemical with an aim of a use in the heat insulation of constructions. The preliminary results obtained showed that this material is extremely porous (porosity >70 %), characterized of a low density and a very low thermal conductivity. These promising properties support the use of this local material in the thermal insulation.

Thermal studies on a mechanical prototype of A BIS MDT chamber

CERN Document Server

Petridou, C; Wotschack, J; Zisis, A

1998-01-01

The deformations of a BIS MDT chamber owing to temperature gradients between the two multilayers and between the two Faraday cages were studied on a mechanical prototype. The influence of thermal insulation on the thermal behaviour of the chamber is also reported.

Impact Verification of Aerogel Insulation Paint on Historic Brick Facades

Science.gov (United States)

Ganobjak, Michal; Kralova, Eva

2017-10-01

Increasing the sustainability of existing buildings is being motivated by reduction of their energy demands. It is the above all the building envelope and its refurbishment by substitution or addition of new materials that makes the opportunity for reduction of energy consumption. A special type of refurbishment is conservation of historical buildings. Preservation of historic buildings permits also application of innovative methods and materials in addition to the original materials if their effects are known and the gained experience ensures their beneficial effect. On the market, there are new materials with addition of silica aerogel in various forms of products. They are also potentially useful in conservation of monuments. However, the effects of aerogel application in these cases are not known. For refurbishment is commercially available additional transparent insulation paint - Nansulate Clear Coat which is containing aerogel and can be used for structured surfaces such as bricks. A series of experiments examined the thermo-physical manifestation of an ultra-thin insulation coating of Nansulate Clear Coat containing silica aerogel on a brick facade. The experiments of active and passive thermography have observed effects of application on the small-scale samples of the brick façade of a protected historical building. Through a series of experiments were measured thermal insulation effect and influence on the aesthetic characteristics such as change in colour and gloss. The treated samples were compared to a reference. Results have shown no thermal-insulating manifestation of the recommended three layers of insulation paint. The three layers recommended by the manufacturer did not significantly affect the appearance of the brick facade. Color and gloss were not significantly changed. Experiments showed the absence of thermal insulation effect of Nansulate transparent triple coating. The thermal insulation effect could likely be reached by more layers of

An Innovative Use of Renewable Ground Heat for Insulation in Low Exergy Building Systems

Directory of Open Access Journals (Sweden)

Hansjürg Leibundgut

2012-08-01

Full Text Available Ground heat is a renewable resource that is readily available for buildings in cool climates, but its relatively low temperature requires the use of a heat pump to extract it for heating. We developed a system that uses low temperature ground heat directly in a building wall to reduce transmission heat losses. The Active Low Exergy Geothermal Insulation Systems (ALEGIS minimizes exergy demand and maximizes the use of renewable geothermal heat from the ground. A fluid is pumped into a small pipe network in an external layer of a wall construction that is linked to a ground heat source. This decouples the building from the outside temperature, therefore eliminating large peak demands and reducing the primary energy demand. Our steady-state analysis shows that at a design temperature of −10 °C the 6 cm thick active insulation system has equivalent performance to 11 cm of passive insulation. Our comparison of heating performance of a building with our active insulation system versus a building with static insulation of the same thickness shows a 15% reduction in annual electricity demand, and thus exergy input. We present an overview of the operation and analysis of our low exergy concept and its modeled performance.

Minimization of thermal insulation thickness taking into account condensation on external walls

Directory of Open Access Journals (Sweden)

Nurettin Yamankaradeniz

2015-09-01

Full Text Available Condensation occurs in the inner layers of construction materials at whatever point the partial pressure of water vapor diffuses and reaches its saturation pressure. Condensation, also called sweating, damages materials, reduces thermal resistance, and by increasing the total heat transfer coefficient, results in unwanted events such as increased heat loss. This study applied minimization of thermal insulation thickness with consideration given to condensation in the external walls. The calculations of heat and mass transfers in the structure elements are expressed in a graphical form. While there was an increase in the required thermal insulation thickness subsequent to an increase in the internal environment’s temperature, relative humidity, and the external environment’s relative humidity, the required thickness decreased with an increase in the external environment’s temperature. The amount of water vapor transferred varied with internal or external conditions and the thickness of the insulation. A change in the vapor diffusion resistance of the insulation material can increase the risk of condensation on the internal or external surfaces of the insulation.

An experimental study on damping characteristics of thermal insulation

International Nuclear Information System (INIS)

Chiba, T.; Kobayashi, H.

1985-01-01

The damping ratio is one of the most important parameters in seismic analysis of nuclear power plant piping systems. Thermal Insulation is considered to contribute to the damping characteristics of piping systems. In the 6th SMiRT conference and 1983 ASME PVP, the damping effect and damping estimating formula was presented as a result of regression analysis from the component tests of 2'' , 4'', and 8'' diameter piping and the proof model test of 1'', 2'' and 4'' piping. In this study, in order to clarify the damping characteristics of larger diameter piping than 8'', the component test of 12'' and 20'' diameter piping with insulation was performed. From the results of these tests and the data survey of the previous papers it was found that the damping ratio of actual piping system with thermal insulation is at least 1% for all size diameter piping

The thermal insulation difference of clothing ensembles on the dry and perspiration manikins

International Nuclear Information System (INIS)

Xiaohong, Zhou; Chunqin, Zheng; Yingming, Qiang; Holmér, Ingvar; Gao, Chuansi; Kuklane, Kalev

2010-01-01

There are about a hundred manikin users around the world. Some of them use the manikin such as 'Walter' and 'Tore' to evaluate the comfort of clothing ensembles according to their thermal insulation and moisture resistance. A 'Walter' manikin is made of water and waterproof breathable fabric 'skin', which simulates the characteristics of human perspiration. So evaporation, condensation or sorption and desorption are always accompanied by heat transfer. A 'Tore' manikin only has dry heat exchange by conduction, radiation and convection from the manikin through clothing ensembles to environments. It is an ideal apparatus to measure the thermal insulation of the clothing ensemble and allows evaluation of thermal comfort. This paper compares thermal insulation measured with dry 'Tore' and sweating 'Walter' manikins. Clothing ensembles consisted of permeable and impermeable clothes. The results showed that the clothes covering the 'Walter' manikin absorbed the moisture evaporated from the manikin. When the moisture transferred through the permeable clothing ensembles, heat of condensation could be neglected. But it was observed that heavy condensation occurred if impermeable clothes were tested on the 'Walter' manikin. This resulted in a thermal insulation difference of clothing ensembles on the dry and perspiration manikins. The thermal insulation obtained from the 'Walter' manikin has to be modified when heavy condensation occurs. The modified equation is obtained in this study

Sprayable Thermal Insulation for Cryogenic Tanks, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — The innovation addressed in this proposal is Sprayable Thermal Insulation for Cryogenic Tanks, or STICT. This novel system could be applied in either an automated or...

Analyzing Design Heating Loads in Superinsulated Buildings

Energy Technology Data Exchange (ETDEWEB)

Arena, Lois [Consortium for Advanced Residential Buildings, Norwalk, CT (United States)

2015-06-01

Super-insulated homes offer many benefits including improved comfort, reduced exterior noise penetration, lower energy bills, and the ability to withstand power and fuel outages under much more comfortable conditions than a typical home. While these homes aren't necessarily constructed with excessive mass in the form of concrete floors and walls, the amount of insulation and the increase in the thickness of the building envelope can lead to a mass effect, resulting in the structures ability to store much more heat than a code built home. This results in a very low thermal inertia making the building much less sensitive to drastic temperature swings thereby decreasing the peak heating load demand. During the winter of 2013/2014, CARB monitored the energy use of three homes in climate zone 6 in an attempt to evaluate the accuracy of two different mechanical system sizing methods for low load homes. Based on the results, it is recommended that internal and solar gains be included and some credit for thermal inertia be used in sizing calculations for super insulated homes.

Highly insulating glazing in new multi-storey buildings; Hoejisolerende glaspartier i nye etageboliger

Energy Technology Data Exchange (ETDEWEB)

Engelund Thomsen, K.; Schmidt, H.; Aggerholm, S.

2001-07-01

The purpose of this report is to illustrate how highly insulating types of glazing can be used in multi-storey buildings for housing in new ways. These are energy efficient and provide good indoor climate and also satisfy requirements to high architectural quality. The project has resulted in a number of design proposal demonstrating how new types of glazing can be fitted into multi-storey buildings and how new facade expressions, space and lighting effects can be obtained by using highly insulating glass areas. The project is collaboration between the architects Boje Lundgaard and Lene Tranberg's Tegnestue, KAB Bygge og Boligadministration and Danish Building and Urban Research. Calculations of heat demand suggest that it is possible to meet the targets outlined in the Danish Government's action plan for energy. Energy 21 by using new types of highly insulating glazing in new buildings. Another 33% reduction of the heating demand is targeted in relation to existing requirements in the Danish Building Regulations 1995 (BR 95) and the Danish Building Regulations for Small Dwellings 1998 (BR-S 98). The project builds on experience gained from 'High-insulated Glass House' (Wittchen and Aggerholm, 1999) built on the housing estage Egebjerggaard in Ballerup, a suburb of Copenhagen. Examples of existing multi-storey buildings with glass facades show extensive use of glazing as early as 1830 in Spain. Walls preceding the curtain wall were built from wood and glass and rested on stone corbels at about 1 m from the load-bearing facade. The first multi-storey buildings with facades entirely made from glass date from the 1920s. The architect Le Corbusier was the first to create a building system that facilitated the construction of non-loadbearing facades. Various conditions must be especially considered at the design of facades with highly insulating glass areas, i.a. type of glass and glazing, solar shadings, frame constructions and airtightness

Impact of external longwave radiation on optimum insulation thickness in Tunisian building roofs based on a dynamic analytical model

International Nuclear Information System (INIS)

Daouas, Naouel

2016-01-01

Highlights: • An efficient tool is proposed for a rigorous energy analysis of building envelope. • The longwave radiation has an important impact on the energy requirements. • Optimum insulation thickness for roofs is rigorously determined in a cost analysis. • The present method is more accurate than the sol–air degree hours method. • The proposed model is applicable to the study of the efficiency of cool roofs. - Abstract: In Tunisia, the building sector is considered as a major issue of energy consumption. A special attention should be drawn to improve the thermal quality of the building envelope with real consideration of the Tunisian climate specificity. One of the most effective measures is the roof insulation. Therefore, the present study is concerned with the determination of the optimum insulation thickness and the resulting energy savings and payback period for two typical roof structures and two types of insulation materials. An efficient analytical dynamic model based on the Complex Finite Fourier Transform (CFFT) is proposed and validated in order to handle the nonlinear longwave radiation (LWR) exchange with the sky. This model provides a short computational time solution of the transient heat transfer through multilayer roofs, which could be a good alternative to some numerical methods. Both heating and cooling annual loads are rigorously estimated and used as inputs to a life-cycle cost analysis. Among the studied cases, the most economical one is the hollow terracotta-based roof insulated with rock wool, where the optimum insulation thickness is estimated to be 7.9 cm, with a payback period of 6.06 years and energy savings up to 58.06% of the cost of energy consumed without insulation. The impact of the LWR exchange component is quantified and the results show its important effect on the annual transmission loads and, consequently, on optimum insulation thickness. A sensitivity analysis shows the efficiency of cool roofs in the Tunisian

The Building Fabric Thermal Performance of Passivhaus Dwellings—Does It Do What It Says on the Tin?

Directory of Open Access Journals (Sweden)

David Johnston

2016-01-01

Full Text Available The Passivhaus (or Passive House Standard is one of the world’s most widely known voluntary energy performance standards. For a dwelling to achieve the Standard and be granted Certification, the building fabric requires careful design and detailing, high levels of thermal insulation, building airtightness, close site supervision and careful workmanship. However, achieving Passivhaus Certification is not a guarantee that the thermal performance of the building fabric as designed will actually be achieved in situ. This paper presents the results obtained from measuring the in situ whole building heat loss coefficient (HLC of a small number of Certified Passivhaus case study dwellings. They are located on different sites and constructed using different technologies in the UK. Despite the small and non-random nature of the dwelling sample, the results obtained from the in situ measurements revealed that the thermal performance of the building fabric, for all of the dwellings, performed very close to the design predictions. This suggests that in terms of the thermal performance of the building fabric, Passivhaus does exactly what it says on the tin.

Comparative study of thermal insulation boards from leaf and bark ...

African Journals Online (AJOL)

Thus, several researches have succeeded in using these plants and agro waste fibres in developing renewable and environmentally friendly thermal insulation products. The aim of this study was to compare the performance of insulation boards made from leave and bark fibres of Pilios tigma thonningii L.in terms of density, ...

Urban area thermal monitoring: Liepaja case study using satellite and aerial thermal data

Science.gov (United States)

Gulbe, Linda; Caune, Vairis; Korats, Gundars

2017-12-01

The aim of this study is to explore large (60 m/pixel) and small scale (individual building level) temperature distribution patterns from thermal remote sensing data and to conclude what kind of information could be extracted from thermal remote sensing on regular basis. Landsat program provides frequent large scale thermal images useful for analysis of city temperature patterns. During the study correlation between temperature patterns and vegetation content based on NDVI and building coverage based on OpenStreetMap data was studied. Landsat based temperature patterns were independent from the season, negatively correlated with vegetation content and positively correlated with building coverage. Small scale analysis included spatial and raster descriptor analysis for polygons corresponding to roofs of individual buildings for evaluating insulation of roofs. Remote sensing and spatial descriptors are poorly related to heat consumption data, however, thermal aerial data median and entropy can help to identify poorly insulated roofs. Automated quantitative roof analysis has high potential for acquiring city wide information about roof insulation, but quality is limited by reference data quality and information on building types, and roof materials would be crucial for further studies.

Two-dimensional thermal analysis of liquid hydrogen tank insulation

Energy Technology Data Exchange (ETDEWEB)

Babac, Gulru; Sisman, Altug [Istanbul Technical University, Energy Institute, Ayazaga campus, 34469 Maslak, Istanbul (Turkey); Cimen, Tolga [Jaguar and Landrover, Banbury Road, Gaydon, Warwick CV35 0RR (United Kingdom)

2009-08-15

Liquid hydrogen (LH{sub 2}) storage has the advantage of high volumetric energy density, while boil-off losses constitute a major disadvantage. To minimize the losses, complicated insulation techniques are necessary. In general, Multi Layer Insulation (MLI) and a Vapor-Cooled Shield (VCS) are used together in LH{sub 2} tanks. In the design of an LH{sub 2} tank with VCS, the main goal is to find the optimum location for the VCS in order to minimize heat leakage. In this study, a 2D thermal model is developed by considering the temperature dependencies of the thermal conductivity and heat capacity of hydrogen gas. The developed model is used to analyze the effects of model considerations on heat leakage predictions. Furthermore, heat leakage in insulation of LH{sub 2} tanks with single and double VCS is analyzed for an automobile application, and the optimum locations of the VCS for minimization of heat leakage are determined for both cases. (author)

An experimental study on damping characteristics of thermal insulation

International Nuclear Information System (INIS)

Chiba, Toshio; Kobayashi, Hiroe; Aida, Shigekazu; Wada, Hidetoshi

1984-01-01

The damping ratio is one of the most important parameters in seismic analysis of piping systems in a nuclear power plant. Thermal insulation is considered contributing to the damping characteristics of piping systems. At the 6th SMiRT and 1983 ASME PVP conferences, the damping effect and damping estimating formula were presented as a result of regression analysis using the component test data for 2,4 and 8B diameter piping and the proof model test for 1,2 and 4B piping system. In this study, in order to clarify the damping characteristics of a larger diameter piping than 8B,the component test of 12 and 20B diameter piping with insulation was performed. From the results of these tests and the data survey of the previous papers, it was found that the damping ratio of anactual piping system with thermal insulation is at minimum 1% for all size diameter piping. (author)

Thermally-insulating layer for nuclear reactors

International Nuclear Information System (INIS)

1975-01-01

The thermally-insulating layer has been designed both for insulating surfaces within the core of a nuclear reactor and transmitting loads such as the core-weight. Said layer comprises a layer of bricks and a layer of tiles with smaller clearance between the tiles than between the bricks, the latter having a reduced cross-section against the tiles so as to be surrounded by relatively large interconnected ducts forming a continuous chamber behind the tile-layer in order to induce a substantial decreases in the transverse flow of the reactor-core coolant. The core preferably comprises hexagonal columns supported by rhomb-shaped plates, with channels distributed so as to mix the coolant of twelve columns. The plates are separated from support-tiles by means of pillars [fr

Technology Solutions for Existing Homes Case Study: Trade-Friendly Retrofit Insulated Panels for Existing Buildings

Energy Technology Data Exchange (ETDEWEB)

None

2016-03-01

For this project with the U.S. Department of Energy Building America team Home Innovation Research Labs, the retrofit insulated panels relied on an enhanced expanded polystyrene (EPS) for thermal resistance of R-4.5/inch, which is an improvement of 10% over conventional (white-colored) EPS. EPS, measured by its life cycle, is an alternative to commonly used extruded polystyrene and spray polyurethane foam. It is a closed-cell product made up of 90% air, and it requires about 85% fewer petroleum products for processing than other rigid foams.

Sensitivity analysis for daily building operation from the energy and thermal comfort standpoint

Directory of Open Access Journals (Sweden)

Ignjatović Marko G.

2016-01-01

Full Text Available Improving energy performance of buildings is one of the most important tasks for reaching sustainability. Assessing building energy consumption is performed more often with specialized simulation tools. Sensitivity analysis proved to be a valuable tool for creating more reliable and realistic building energy models and better buildings. This paper briefly describes the methodology for running global sensitivity analysis and tools that can be used, and presents the results of such an analysis conducted for winter period, daily, on input variables covering a real building's operation, control and occupant related parameters that affect both thermal comfort and heating energy consumption. Two sets of inputs were created. The only difference between these sets is an addition of clothing insulation and occupant heat gain as input variables. The reference building was simulated for three distinctive winter weeks. Two additional input variables have an effect especially on thermal comfort, but they do not disturb the relative order of other influential input variables. The common influential variables for both energy consumption and thermal comfort were identified and are: air handling unit sup-ply temperature and airflow rate and control system related parameters. This can help in future research into implementing the simulation-assisted optimized operation in real buildings. [Projekat Ministarstva nauke Republike Srbije, br. TR-33051: The concept of sustainable energy supply of settlements with energy efficient buildings

Thermal test of the insulation structure for LH 2 tank by using the large experimental apparatus

Science.gov (United States)

Kamiya, S.; Onishi, K.; Konshima, N.; Nishigaki, K.

Conceptual designs of large mass LH 2 (liquid hydrogen) storage systems, whose capacity is 50,000 m3, have been studied in the Japanese hydrogen project, World Energy Network (WE-NET) [K. Fukuda, in: WE-NET Hydrogen Energy Symposium, 1999, P1-P41]. This study has concluded that their thermal insulation structures for the huge LH 2 tanks should be developed. Their actual insulation structures comprise not only the insulation material but also reinforced members and joints. To evaluate their thermal performance correctly, a large test specimen including reinforced members and joints will be necessary. After verifying the thermal performance of a developed large experimental apparatus [S. Kamiya, Cryogenics 40 (1) (2000) 35] for measuring the thermal conductance of various insulation structures, we tested two specimens, a vacuum multilayer insulation (MLI) with a glass fiber reinforced plastic (GFRP) support and a vacuum solid insulation (microtherm ®) with joints. The thermal background test for verifying the thermal design of the experimental apparatus showed that the background heat leak is 0.1 W, small enough to satisfy apparatus performance requirement. The thermal conductance measurements of specimens also showed that thermal heat fluxes of MLI with a GFRP support and microtherm ® are 8 and 5.4 W/m2, respectively.

Effect of Nano Al2O3 Doping on Thermal Aging Properties of Oil-Paper Insulation

Directory of Open Access Journals (Sweden)

Ningchuan Liang

2018-05-01

Full Text Available The thermal aging property of oil-paper insulation is a key factor affecting the service life of transformers. In this study, nano-Al2O3 was added to insulating paper to improve its anti-thermal aging property and delay the aging rate of the insulating oil. The composite paper containing 2% nano-Al2O3 had the highest tensile strength and therefore was selected for the thermal aging test. The composite and normal papers were treated with an accelerated thermal aging experiment at the temperature of 130 °C for 56 days. The variations of the degree of polymerization (DP and tensile strength of the insulating papers with aging time were obtained. The characteristics of the insulating oil, including color, acid content, breakdown voltage, and dielectric loss were analyzed. The results revealed that compared with a plain paper, the composite paper maintained a higher DP, and its tensile strength decreased more slowly during the aging process. The oil-impregnated composite paper presented a lighter-colored oil, less viscosity changes, and a considerably lower quantity of thermal aging products. In addition, nano-Al2O3 can effectively adsorb copper compounds and keep part of the acid products and water away from the thermal aging process. This characteristic restrained the catalysis of copper compounds and H+ in the thermal aging reaction and reduced the thermal aging speed of both the insulating paper and the insulating oil.

Thermal performances of an insulating structure for a reactor vessel

International Nuclear Information System (INIS)

Aranovitch, E.; Crutzen, S.; Le Det, M.; Denis, R.

1974-12-01

This report describes the thermal and technological tests performed on a multilayer thermal insulation system for high temperature gas reactors. It includes the description of test facilities, global tests, interpretation of data, and technological tests. Results obtained make it possible to predetermine with a satisfactory precision thermal performances under various nominal conditions

Thermal mass vs. insulation building envelope design in six climatic regions of South Africa

CSIR Research Space (South Africa)

Kumirai, T

2012-02-01

Full Text Available is defined in Ecotect as a homogenous enclosed volume of air. In most cases this corresponds to a single room. It is assumed that the air within a zone is able to mix freely. Every room in the simulation model was defined as distinct thermal zone... of the Ecotect simulation model and simulation of houses with base case characteristics and energy efficient measures in six South African cities. 3.1 Building infiltration rate measurements High infiltration rates means a leaky building meaning...

Dynamic Heat Production Modeling for Life Cycle Assessment of Insulation in Danish Residential Buildings

DEFF Research Database (Denmark)

Sohn, Joshua L.; Kalbar, Pradip; Birkved, Morten

2017-01-01

insulation in a Danish single-family detached home. This single family house, is based on averages of current Danish construction practices with building heat losses estimated using Be10. To simulate a changing district heating grid mix, heat supply fuel sources are modeled according to Danish energy mix...... for space heating without insulation over the lifespan of a building. When the energy sources for insulation production are similar to the energy mix that supplies heat, this logic is valid to very high level of insulation. However, in Denmark, as well as many other countries this assumption is becoming...... increasingly incorrect. Given the generally long service life of buildings, the significance of future energy mixes, which are expected/intended to have a smaller environmental impact, can be great. In this paper, a reference house is used to assess the life cycle environmental impacts of mineral wool...

Insulating materials from renewable raw materials. 4. ed.; Daemmstoffe aus nachwachsenden Rohstoffen

Energy Technology Data Exchange (ETDEWEB)

Brandhorst, Joerg; Spritzendorfer, Josef; Gildhorn, Kai; Hemp, Markus

2012-03-27

The thermal insulation has become a central issue in the construction and renovation of buildings. The question of healthy building materials and appropriate construction follows the desire of a comfartable and allergy-free living. Due to these developments, insulation materials from renewable resources increasingly has raised the consciousness. The brochure under consideration describes the dynamic market of insulation materials consisting of renewable raw materials. Wood fibers, wood wool, sheep wool, flax, hemp, reeds, meadow grass, cork, cellulose, seaweed and bulrushes are considered as renewable raw materials for insulating materials.

Sustainable hemp-based composites for the building industry application

Science.gov (United States)

Schwarzova, Ivana; Stevulova, Nadezda; Junak, Jozef; Hospodarova, Viola

2017-07-01

Sustainability goals are essential driving principles for the development of innovative materials in the building industry. Natural plant (e.g. hemp) fibers represent an attractive alternative as reinforcing material due to its good properties and sustainability prerequisites. In this study, hemp-based composite materials, designed for building application as non-load bearing material, providing both thermal insulation and physico-mechanical properties, are presented. Composite materials were produced by bonding hemp hurds with a novel inorganic binder (MgO-based cement) and then were characterized in terms of physical properties (bulk density, water absorption), thermal properties (thermal conductivity) and mechanical properties (compressive and tensile strength). The composites exhibited promising physical, thermal and mechanical characteristics, generally comparable to commercially available products. In addition, the hemp-based composites have the advantage of a significantly low environmental impact (thanks to the nature of both the dispersed and the binding phase) and no negative effects on human health. All things considered, the composite materials seem like very promising materials for the building industry application.

Thermal highly porous insulation materials made of mineral raw materials

Science.gov (United States)

Mestnikov, A.

2015-01-01

The main objective of the study is to create insulating foam based on modified mineral binders with rapid hardening. The results of experimental studies of the composition and properties of insulating foam on the basis of rapidly hardening Portland cement (PC) and gypsum binder composite are presented in the article. The article proposes technological methods of production of insulating foamed concrete and its placement to the permanent shuttering wall enclosures in monolithic-frame construction and individual energy-efficient residential buildings, thus reducing foam shrinkage and improving crack-resistance.

High Performance Slab-on-Grade Foundation Insulation Retrofits

Energy Technology Data Exchange (ETDEWEB)

Goldberg, Louise F. [NorthernSTAR, St. Paul, MN (United States); Mosiman, Garrett E. [NorthernSTAR, St. Paul, MN (United States)

2015-09-01

?A more accurate assessment of SOG foundation insulation energy savings than traditionally possible is now feasible. This has been enabled by advances in whole building energy simulation with 3-dimensional foundation modelling integration at each time step together with an experimental measurement of the site energy savings of SOG foundation insulation. Ten SOG insulation strategies were evaluated on a test building to identify an optimum retrofit insulation strategy in a zone 6 climate (Minneapolis, MN). The optimum insulation strategy in terms of energy savings and cost effectiveness consisted of two components: (a) R-20 XPS insulation above grade, and, (b) R-20 insulation at grade (comprising an outer layer of R-10 insulation and an interior layer of R-12 poured polyurethane insulation) tapering to R-10 XPS insulation at half the below-grade wall height (the lower half of the stem wall was uninsulated). The optimum insulation strategy was applied to single and multi-family residential buildings in climate zone 4 - 7. The highest site energy savings of 5% was realized for a single family home in Duluth, MN, and the lowest savings of 1.4 % for a 4-unit townhouse in Richmond, VA. SOG foundation insulation retrofit simple paybacks ranged from 18 to 47 years. There are other benefits of SOG foundation insulation resulting from the increase in the slab surface temperatures. These include increased occupant thermal comfort, and a decrease in slab surface condensation particularly around the slab perimeter.

Life-cycle based dynamic assessment of mineral wool insulation in a Danish residential building application

DEFF Research Database (Denmark)

Sohn, Joshua L.; Kalbar, Pradip; Banta, Gary T.

2017-01-01

There has been significant change in the way buildings are constructed and the way building energy performance is evaluated. Focus on solely the use phase of a building is beginning to be replaced by a life-cycle based performance assessment. This study assesses the environmental impact trade......-offs between the heat produced to meet a building's space heating load and insulation produced to reduce its space heating load throughout the whole life-cycle of a building. To obtain a more realistic valuation of this tradeoff, a dynamic heat production model, which accounts for political projections...... grid, which is potentially promoted at present in Danish regulation. It is further concluded that improvement of the mineral wool insulation production process could allow for greater levels of environmentally beneficial insulation and would also help in reducing the overall environmental burden from...

Sound insulation between dwellings - Descriptors applied in building regulations in Europe

DEFF Research Database (Denmark)

Rasmussen, Birgit; Rindel, Jens Holger

2010-01-01

Regulatory sound insulation requirements for dwellings have existed since the 1950s in some countries and descriptors for evaluation of sound insulation have existed for nearly as long. However, the descriptors have changed considerably over time, from simple arithmetic averaging of frequency bands...... was carried out of legal sound insulation requirements in 24 countries in Europe. The comparison of requirements for sound insulation between dwellings revealed significant differences in descriptors as well as levels. This paper focuses on descriptors and summarizes the history of descriptors, the problems...... of the present situation and the benefits of consensus concerning descriptors for airborne and impact sound insulation between dwellings. The descriptors suitable for evaluation should be well-defined under practical situations in buildings and be measurable. Measurement results should be reproducible...

Modeling thermal performance of exterior walls retrofitted from insulation and modified laterite based bricks materials

Science.gov (United States)

Wati, Elvis; Meukam, Pierre; Damfeu, Jean Claude

2017-12-01

Uninsulated concrete block walls commonly found in tropical region have to be retrofitted to save energy. The thickness of insulation layer used can be reduced with the help of modified laterite based bricks layer (with the considerably lower thermal conductivity than that of concrete block layer) during the retrofit building fabrics. The aim of this study is to determine the optimum location and distribution of different materials. The investigation is carried out under steady periodic conditions under the climatic conditions of Garoua in Cameroon using a Simulink model constructed from H-Tools (the library of Simulink models). Results showed that for the continuous air-conditioned space, the best wall configuration from the maximum time lag, minimum decrement factor and peak cooling transmission load perspective, is dividing the insulation layer into two layers and placing one at the exterior surface and the other layer between the two different massive layers with the modified laterite based bricks layer at the interior surface. For intermittent cooling space, the best wall configuration from the minimum energy consumption depends on total insulation thickness. For the total insulation thickness less than 8 cm approximately, the best wall configuration is placing the half layer of insulation material at the interior surface and the other half between the two different massive layers with the modified earthen material at the exterior surface. Results also showed that, the optimum insulation thickness calculated from the yearly cooling transmission (estimated only during the occupied period) and some economic considerations slightly depends on the location of that insulation.

Impact of building forms on thermal performance and thermal comfort conditions in religious buildings in hot climates: a case study in Sharjah city

Science.gov (United States)

Mushtaha, Emad; Helmy, Omar

2017-11-01

The common system used for thermal regulation in mosques of United Arab Emirates (UAE) is the heating, ventilating and air-conditioning (HVAC) system. This system increases demands on energy consumption and increases CO2 emission. A passive design approach is one of the measures to reduce these problems. This study involved an analytical examination of building forms, followed by testing the impact of these forms on its thermal performance and indoor thermal comfort. The tests were conducted using energy simulations software packages. Passive parameters such as shading devices, thermal insulation and natural ventilation were applied in six cases, including the baseline case within each form. The obtained results showed a significant effect of mosque forms as well as passive design techniques on the thermal comfort within the structures. The findings confirmed that the use of passive design alone would not help achieve thermal comfort, but reduce the annual energy consumption by10%. By integrating a hybrid air-conditioning system as another supporting approach, the annual energy consumption could be reduced by 67.5%, which allows for the designing of a much smaller HVAC system.

External Insulation of Masonry Walls and Wood Framed Walls

Energy Technology Data Exchange (ETDEWEB)

Baker, P.

2013-01-01

The use of exterior insulation on a building is an accepted and effective means to increase the overall thermal resistance of the assembly that also has other advantages of improved water management and often increased air tightness of building assemblies. For thin layers of insulation (1" to 1 1/2"), the cladding can typically be attached directly through the insulation back to the structure. For thicker insulation layers, furring strips have been added as a cladding attachment location. This approach has been used in the past on numerous Building America test homes and communities (both new and retrofit applications), and has been proven to be an effective and durable means to provide cladding attachment. However, the lack of engineering data has been a problem for many designers, contractors, and code officials. This research project developed baseline engineering analysis to support the installation of thick layers of exterior insulation on existing masonry and frame walls. Furthermore, water management details necessary to integrate windows, doors, decks, balconies and roofs were created to provide guidance on the integration of exterior insulation strategies with other enclosure elements.

A Thermally Insulating Textile Inspired by Polar Bear Hair.

Science.gov (United States)

Cui, Ying; Gong, Huaxin; Wang, Yujie; Li, Dewen; Bai, Hao

2018-04-01

Animals living in the extremely cold environment, such as polar bears, have shown amazing capability to keep warm, benefiting from their hollow hairs. Mimicking such a strategy in synthetic fibers would stimulate smart textiles for efficient personal thermal management, which plays an important role in preventing heat loss and improving efficiency in house warming energy consumption. Here, a "freeze-spinning" technique is used to realize continuous and large-scale fabrication of fibers with aligned porous structure, mimicking polar bear hairs, which is difficult to achieve by other methods. A textile woven with such biomimetic fibers shows an excellent thermal insulation property as well as good breathability and wearability. In addition to passively insulating heat loss, the textile can also function as a wearable heater, when doped with electroheating materials such as carbon nanotubes, to induce fast thermal response and uniform electroheating while maintaining its soft and porous nature for comfortable wearing. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Investigation of properties of low-strength lightweight concrete for thermal insulation

Energy Technology Data Exchange (ETDEWEB)

UEnal, Osman; Uygunoglu, Tayfun [Construction Department, Technical Education Faculty, Afyon Kocatepe University, 03200 Afyon (Turkey); Yildiz, Ahmet [Afyon Kocatepe University, Engineering Faculty, 03200 Afyon (Turkey)

2007-02-15

In this study, block elements with diatomite, which have different aggregate granulometries and cement contents, were produced and the effect of these parameters on physical and mechanical properties of block elements were investigated. Diatomite samples were taken from the region of Afyon. In the mixes, water/cement ratio was kept at 0.15. Analyses include compressive strength, thermal conductivity, ultrasonic velocity tests, bulk density and specific porosity. According to experimental results, while dry unit weight is varied between 900 and 1190kg/m{sup 3}, compressive strength of 7-56 days specimens ranged from 2.5 to 8MPa. Materials with a ratio of 30% fine, 40% medium and 30% coarse size have the best compressive strength and thermal insulation in all series. Due to low thermal conductivity, lightweight aggregate concrete with diatomite can be used to prove high isolation in the structure. (author)

Property comparisons of commercially available silica-based microporous insulations I. Machinability and thermal dimensional stability

International Nuclear Information System (INIS)

Kramer, Daniel P.; McNeil, Dennis C.; Ruhkamp, Joseph D.; Wells, Donna J.; Stringer, Robert L.; Howell, Edwin I.

2002-01-01

Maximizing the thermal to electrical conversion efficiency of a nuclear space power system requires that all of the available thermal energy be utilized in the most efficient manner. Microporous insulations are attractive for application in space power systems due to their very low thermal conductivity. Over the last few years, several new silica-based microporous insulating materials have become commercially available. Property comparisons of the various insulations obtained from company literature and experiments on microporous sample specimens are discussed. The results demonstrate that their machinability and thermal dimensional stability as a function of time at temperature and atmosphere are dependent on the particular material

Energy efficiency and comfort conditions in passive solar buildings: Effect of thermal mass at equatorial high altitudes

Science.gov (United States)

Ogoli, David Mwale

This dissertation is based on the philosophy that architectural design should not just be a function of aesthetics, but also of energy-efficiency, advanced technologies and passive solar strategies. A lot of published literature is silent regarding buildings in equatorial highland regions. This dissertation is part of the body of knowledge that attempts to provide a study of energy in buildings using thermal mass. The objectives were to establish (1) effect of equatorial high-altitude climate on thermal mass, (2) effect of thermal mass on moderating indoor temperatures, (3) effect of thermal mass in reducing heating and cooling energy, and (4) the amount of time lag and decrement factor of thermal mass. Evidence to analyze the effect of thermal mass issues came from three sources. First, experimental physical models involving four houses were parametrically conducted in Nairobi, Kenya. Second, energy computations were made using variations in thermal mass for determining annual energy usage and costs. Third, the data gathered were observed, evaluated, and compared with currently published research. The findings showed that: (1) Equatorial high-altitude climates that have diurnal temperature ranging about 10--15°C allow thermal mass to moderate indoor temperatures; (2) Several equations were established that indicate that indoor mean radiant temperatures can be predicted from outdoor temperatures; (3) Thermal mass can reduce annual energy for heating and cooling by about 71%; (4) Time lag and decrement of 200mm thick stone and concrete thermal mass can be predicted by a new formula; (5) All windows on a building should be shaded. East and west windows when shaded save 51% of the cooling energy. North and south windows when fully shaded account for a further 26% of the cooling energy; (6) Insulation on the outside of a wall reduces energy use by about 19.6% below the levels with insulation on the inside. The basic premise of this dissertation is that decisions that

Research and Development Data to Define the Thermal Performance of Reflective Materials Used to Conserve Energy in Building Applications

Energy Technology Data Exchange (ETDEWEB)

Eisenberg, J

2001-04-09

A comprehensive experimental laboratory study has been conducted on the thermal performance of reflective insulation systems. The goal of this study was to develop test and evaluation protocols and to obtain thermal performance data on a selected number of idealized and commercial systems containing reflective airspaces for use in analytical models. Steady-state thermal resistance has been measured on 17 different test panels using two guarded hot boxes. Additional instrumentation was installed to measure the temperature of critical locations inside the test panels. The test parameters which have been studied are heat flow direction (horizontal, up, and down), number of airspaces comprising the cavity, airspace effective emittance, airspace aspect ratio, airspace mean temperature and temperature difference, and the thermal resistance of the stud material. Tests have also been performed on similar constructions with mass insulation. Two one-dimensional calculation techniques (ASHRAE and proposed ASTM) have been employed to determine the cavity thermal resistance from the measured test panel results. The measured cavity thermal resistance is compared with literature data which is commonly employed to calculate the thermal resistance of reflective airspace assemblies. A consumer-oriented handbook pertaining to reflective insulation for building and commercial applications has also been prepared as part of this study.

A Literature Review of Sealed and Insulated Attics—Thermal, Moisture and Energy Performance

Energy Technology Data Exchange (ETDEWEB)

Less, Brennan [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Walker, Iain [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Levinson, Ronnen [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

2016-08-01

In this literature review and analysis, we focus on the thermal, moisture and energy performance of sealed and insulated attics in California climates. Thermal. Sealed and insulated attics are expected to maintain attic air temperatures that are similar to those in the house within +/- 10°F. Thermal stress on the assembly, namely high shingle and sheathing temperatures, are of minimal concern. In the past, many sealed and insulated attics were constructed with insufficient insulation levels (~R-20) and with too much air leakage to outside, leading to poor thermal performance. To ensure high performance, sealed and insulated attics in new California homes should be insulated at levels at least equivalent to the flat ceiling requirements in the code, and attic envelopes and ducts should be airtight. We expect that duct systems in well-constructed sealed and insulated attics should have less than 2% HVAC system leakage to outside. Moisture. Moisture risk in sealed and insulated California attics will increase with colder climate regions and more humid outside air in marine zones. Risk is considered low in the hot-dry, highly populated regions of the state, where most new home construction occurs. Indoor humidity levels should be controlled by following code requirements for continuous whole-house ventilation and local exhaust. Pending development of further guidance, we recommend that the air impermeable insulation requirements of the International Residential Code (2012) be used, as they vary with IECC climate region and roof finish. Energy. Sealed and insulated attics provide energy benefits only if HVAC equipment is located in the attic volume, and the benefits depend strongly on the insulation and airtightness of the attic and ducts. Existing homes with leaky, uninsulated ducts in the attic should have major savings. When compared with modern, airtight duct systems in a vented attic, sealed and insulated attics in California may still provide substantial benefit

Sodium alginate adhesives as binders in wood fibers/textile waste fibers biocomposites for building insulation.

Science.gov (United States)

Lacoste, Clément; El Hage, Roland; Bergeret, Anne; Corn, Stéphane; Lacroix, Patrick

2018-03-15

Alginate derived from seaweed is a natural polysaccharide able to form stable gel through carbohydrate functional groups largely used in the food and pharmaceutical industry. This article deals with the use of sodium alginate as an adhesive binder for wood fibres/textile waste fibres biocomposites. Several aldehyde-based crosslinking agents (glyoxal, glutaraldehyde) were compared for various wood/textile waste ratios (100/0, 50/50, 60/40, 70/30 and 0/100 in weight). The fully biomass derived composites whose properties are herewith described satisfy most of the appropriate requirements for building materials. They are insulating with a thermal conductivity in the range 0.078-0.089 W/m/K for an average density in the range 308-333 kg/m3 according to the biocomposite considered. They are semi-rigid with a maximal mechanical strength of 0.84 MPa under bending and 0.44 MPa under compression for 60/40 w/w wood/textile waste biocomposites with a glutaraldehyde crosslinking agent. Copyright © 2017 Elsevier Ltd. All rights reserved.

Thermally assisted ordering in Mott insulators

Science.gov (United States)

Sims, Hunter; Pavarini, Eva; Koch, Erik

2017-08-01

Landau theory describes phase transitions as the competition between energy and entropy: The ordered phase has lower energy, while the disordered phase has larger entropy. When heating the system, ordering is reduced entropically until it vanishes at the critical temperature. This picture implicitly assumes that the energy difference between the ordered and disordered phases does not change with temperature. We show that for orbital ordering in the Mott insulator KCuF3, this assumption fails qualitatively: entropy plays a negligible role, while thermal expansion energetically stabilizes the orbitally ordered phase to such an extent that no phase transition is observed. To understand this strong dependence on the lattice constant, we need to take into account the Born-Mayer repulsion between the ions. It is the latter, and not the Jahn-Teller elastic energy, which determines the magnitude of the distortion. This effect will be seen in all materials where the distortion expected from the Jahn-Teller mechanism is so large that the ions would touch. Our mechanism explains not only the absence of a phase transition in KCuF3, but even suggests the possibility of an inverted transition in closed-shell systems, where the ordered phase emerges only at high temperatures.

Performance Analysis of Cool Roof, Green Roof and Thermal Insulation on a Concrete Flat Roof in Tropical Climate

OpenAIRE

Zingre, Kishor T.; Yang, Xingguo; Wan, Man Pun

2015-01-01

In the tropics, the earth surface receives abundant solar radiation throughout the year contributing significantly to building heat gain and, thus, cooling demand. An effective method that can curb the heat gains through opaque roof surfaces could provide significant energy savings. This study investigates and compares the effectiveness of various passive cooling techniques including cool roof, green roof and thermal insulation for reducing the heat gain through a flat concrete roof in tropic...

Quantitative analysis of silica aerogel-based thermal insulation coatings

DEFF Research Database (Denmark)

Kiil, Søren

2015-01-01

containing intact hollow glass or polymer spheres showed that silica aerogel particles are more efficient in an insulation coating than hollow spheres. In a practical (non-ideal) comparison, the ranking most likely cannot be generalized. A parameter study demonstrates how the model can be used, qualitatively......A mathematical heat transfer model for a silica aerogel-based thermal insulation coating was developed. The model can estimate the thermal conductivity of a two-component (binder-aerogel) coating with potential binder intrusion into the nano-porous aerogel structure. The latter is modelled using...... a so-called core–shell structure representation. Data from several previous experimental investigations with silica aerogels in various binder matrices were used for model validation. For some relevant cases with binder intrusion, it was possible to obtain a very good agreement between simulations...

Methodology for characterization of corrosive agents of thermal insulating foams; Desenvolvimento de metodologia para caracterizacao de agentes corrosivos de espumas de isolamento termico

Energy Technology Data Exchange (ETDEWEB)

Sousa, Flavio V. Vasques de [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia. Fundacao Coordenacao de Projetos, Pesquisas e Estudos Tecnologicos - COPPETEC; Mattos, Oscar R.; Mota, Rafael O. da [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia. Programa de Engenharia Metalurgica e de Materiais; Margarit-Mattos, Isabel C.P. [Universidade Federal, Rio de Janeiro, RJ (Brazil). Escola de Quimica. Dept. de Processos Organicos; Quintela, Joaquim P. [PETROBRAS, Rio de Janeiro, RJ (Brazil); Vieira, Magda M. [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas

2005-07-01

Warming up oil and derivatives is a required procedure to make their transportation more efficient due to the increase in fluidity. Therefore, the use of thermally insulated pipeline becomes essential. The commonly practice has been the use of pipelines covered with an optional anticorrosive coating, followed by a polyurethane foam layer, as thermal insulator, and a polyethylene top coating for mechanical protection. During the life time of the pipeline, local ruptures of the polyethylene coating frequently occur, allowing the water permeation throughout the thermal insulator. This water may cause foam leaching that would release corrosive agents on the external wall pipe. The objective of the present work was to investigate the effects of the blowing agents, the addition of flame retardant to the foam as well as operating temperatures on the generation of corrosive solutions on the external wall of thermally insulated pipes. In this sense, polyurethane foams expanded with HCFC-141b, CFC-11 and CO{sub 2}, with and without flame retardant, were evaluated at the temperatures of 80 and 120 deg C. (author)

Effect of Insulation Thickness on Thermal Stratification in Hot Water Tanks

Directory of Open Access Journals (Sweden)

Burak KURŞUN

2018-03-01

Full Text Available One of the important factors to be considered in increasing the efficiency of hot water storage tanks used for thermal energy storage is thermal stratification. Reducing the temperature of the water at the base of the tank provides more utilization of the energy of the heat source during the heating of the water and improves the efficiency of the system. In this study, the effect of the insulation thickness on the outer surface of the tank and the ratio of the tank diameter to the height (D/H on the thermal stratification was investigated numerically. Numerical analyzes were carried out for the condition that the insulation thickness was constant and variable in the range of D/H=0,3-1. Water was used as the heat storage fluid and the analysis results were obtained for eight hours cooling period. Numerical results showed that the temperature difference between the bottom and top surfaces of the tank increased between 7-9 ° C for the range of D / H = 0,3-1 with changing the insulation thickness.

Hydrogen removal from LWR containments by catalytic-coated thermal insulation elements (THINCAT)

International Nuclear Information System (INIS)

Fischer, K.; Broeckerhoff, P.; Ahlers, G.; Gustavsson, V.; Herranz, L.; Polo, J.; Dominguez, T.; Royl, P.

2003-01-01

In the THINCAT project, an alternative concept for hydrogen mitigation in a light water reactor (LWR) containment is being developed. Based on catalytic coated thermal insulation elements of the main coolant loop components, it could be considered either as an alternative to backfitting passive autocatalytic recombiner devices, or as a reinforcement of their preventive effect. The present paper summarises the results achieved at about project mid-term. Potential advantages of catalytic thermal insulation studied in the project are:-reduced risk of unintended ignition,;-no work space obstruction in the containment,;-no need for seismic qualification of additional equipment,;-improved start-up behaviour of recombination reaction. Efforts to develop a suitable catalytic layer resulted in the identification of a coating procedure that ensures high chemical reactivity and mechanical stability. Test samples for use in forthcoming experiments with this coating were produced. Models to predict the catalytic rates were developed, validated and applied in a safety analysis study. Results show that an overall hydrogen concentration reduction can be achieved which is comparable to the reduction obtained using conventional recombiners. Existing experimental information supports the argument of a reduced ignition risk

Numerical Simulation of Natural Convection in a Vertically Installed Wet Thermal Insulator

Energy Technology Data Exchange (ETDEWEB)

Bae, Youngmin; Kim, Seong H.; Seo, Jae K.; Kim, Young I. [KAERI, Daejeon (Korea, Republic of)

2016-05-15

Natural convection in an enclosure with disconnected vertical partitions inside is thought of as major concerns in the design of thermal insulators. For example, in a system-integrated modular advanced reactor (SMART), vertical partitions are disposed inside the so-called wet thermal insulator with gaps at the top and bottom ends to compensate for thermal expansion . In such a case, buoyancy driven flow circulates throughout the enclosure, i.e., fluid rises up in the hot-side layers, passing through the gap at the top, moving downward in the vertical channels near the cold side, and returning to the hot-side layers via the gap at the bottom. Compared with the case of connected partitions, this often causes an undesirable increase in the circulation flow rate and heat transfer within the enclosure, thus deteriorating the thermal insulation performance. In this study, laminar natural convection in a tall rectangular enclosure with disconnected vertical partitions inside is investigated numerically. The effects of main governing parameters such as the modified Rayleigh number, enclosure height to width ratio, and number of fluid layers are scrutinized along with a discussion of the heat transfer regimes. This study investigates the laminar natural convection in a tall rectangular enclosure having isothermal side walls of different temperatures and insulated top and bottom walls with disconnected vertical partitions inside.

Numerical Simulation of Natural Convection in a Vertically Installed Wet Thermal Insulator

International Nuclear Information System (INIS)

Bae, Youngmin; Kim, Seong H.; Seo, Jae K.; Kim, Young I.

2016-01-01

Natural convection in an enclosure with disconnected vertical partitions inside is thought of as major concerns in the design of thermal insulators. For example, in a system-integrated modular advanced reactor (SMART), vertical partitions are disposed inside the so-called wet thermal insulator with gaps at the top and bottom ends to compensate for thermal expansion . In such a case, buoyancy driven flow circulates throughout the enclosure, i.e., fluid rises up in the hot-side layers, passing through the gap at the top, moving downward in the vertical channels near the cold side, and returning to the hot-side layers via the gap at the bottom. Compared with the case of connected partitions, this often causes an undesirable increase in the circulation flow rate and heat transfer within the enclosure, thus deteriorating the thermal insulation performance. In this study, laminar natural convection in a tall rectangular enclosure with disconnected vertical partitions inside is investigated numerically. The effects of main governing parameters such as the modified Rayleigh number, enclosure height to width ratio, and number of fluid layers are scrutinized along with a discussion of the heat transfer regimes. This study investigates the laminar natural convection in a tall rectangular enclosure having isothermal side walls of different temperatures and insulated top and bottom walls with disconnected vertical partitions inside

Insulation Reformulation Development

Science.gov (United States)

Chapman, Cynthia; Bray, Mark

2015-01-01

The current Space Launch System (SLS) internal solid rocket motor insulation, polybenzimidazole acrylonitrile butadiene rubber (PBI-NBR), is a new insulation that replaced asbestos-based insulations found in Space Shuttle heritage solid rocket boosters. PBI-NBR has some outstanding characteristics such as an excellent thermal erosion resistance, low thermal conductivity, and low density. PBI-NBR also has some significant challenges associated with its use: Air entrainment/entrapment during manufacture and lay-up/cure and low mechanical properties such as tensile strength, modulus, and fracture toughness. This technology development attempted to overcome these challenges by testing various reformulated versions of booster insulation. The results suggest the SLS program should continue to investigate material alternatives for potential block upgrades or use an entirely new, more advanced booster. The experimental design was composed of a logic path that performs iterative formulation and testing in order to maximize the effort. A lab mixing baseline was developed and documented for the Rubber Laboratory in Bldg. 4602/Room 1178.

Complex evaluation of properties for some thermal insulating materials of NPP

International Nuclear Information System (INIS)

Yurchenko, V.G.; Nazarova, G.A.; Yakunichev, V.N.; Potulov, V.V.; Kazakova, K.A.

1991-01-01

The effects of the main operational factors (temperature, ionizing radiation, increased humidity) on some most widely applied fibrous materials are investigated. The samples were irradiated by 60 Co gamma photons at the PKhM-gamma-20 device in air at temperature of 40±1 deg C in order to analyze the radiation resistance of thermal insulating materials. The analysis and generalization of the results of laboratory tests give an opportunity to make the following conclusions. The thermal insulation articles and constructions made of superfine basalt fiber may be used in the zones of rigorous regime. The superfine glass fibers (GF) are recommended to be used for equipment and pipeline shielding in the zones of rigorous control only as a part of multilayer insulation as the second or next layers and only in places where leaks are impossible

Graded thermal insulation layer systems; Gradierte Waermedaemmschichtsysteme

Energy Technology Data Exchange (ETDEWEB)

Leushake, U.; Krell, T. [Deutsche Forschungsanstalt fuer Luft- und Raumfahrt e.V. (DLR), Koeln (Germany). Inst. fuer Werkstoff-Forschung

1996-12-31

Graded thermal insulation systems reduce local stresses between two layers. Grading usually involves a concentration variation in a second phase but may also involve variations of the microstructure or chemical composition. The contribution discusses the application of this technique for thermal protection of turbine blades in aircraft propulsion systems. [Deutsch] Mit Hilfe gradierter Waermeschichtsysteme ist es moeglich die lokalen Spannungen zwischen zwei Schichten zu verringern. Die Gradierung umfasst meistens eine Variation des Gehaltes einer zweiten Phase, kann aber auch die Variation der Mikrostruktur oder der chemischen Zusammensetzung beinhalten. In diesem Beitrag wird auf die Anwendung als thermischer Schutz von Turbinenschaufeln fuer Flugtriebwerke eingegangen.

Health impacts due to personal exposure to fine particles caused by insulation of residential buildings in Europe

Science.gov (United States)

Gens, Alexandra; Hurley, J. Fintan; Tuomisto, Jouni T.; Friedrich, Rainer

2014-02-01

The insulation of residential buildings affects human exposure to fine particles. According to current EU guidelines, insulation is regulated for energy saving reasons. As buildings become tighter, the air exchange rate is reduced and, thus, the indoor concentration of pollutants is increased if there are significant indoor sources. While usually the effects of heat insulation and increase of the air-tightness of buildings on greenhouse gas emissions are highlighted, the negative impacts on human health due to higher indoor concentrations are not addressed. Thus, we investigated these impacts using scenarios in three European countries, i. e. Czech Republic, Switzerland and Greece. The assessment was based on modelling the human exposure to fine particles originating from sources of particles within outdoor and indoor air, including environmental tobacco smoke. Exposure response relationships were derived to link (adverse) health effects to the exposure. Furthermore, probable values for the parameters influencing the infiltration of fine particles into residential buildings were modelled. Results show that the insulation and increase of the air-tightness of residential buildings leads to an overall increase of the mean population exposure - and consequently adverse health effects - in all considered countries (ranging for health effects from 0.4% in Czech Republic to 11.8% in Greece for 100% insulated buildings) due to an accumulation of particles indoors, especially from environmental tobacco smoke. Considering only the emission reductions in outdoor air (omitting changes in infiltration parameters) leads to a decrease of adverse health effects. This study highlights the importance of ensuring a sufficient air exchange rate when insulating buildings, e. g. by prescribing heat ventilation and air conditioning systems in new buildings and information campaigns on good airing practice in renovated buildings. It also shows that assessing policy measures based on the

Improvement of the thermal behavior of linear motors through insulation layer

International Nuclear Information System (INIS)

Eun, I. U.; Lee, C. M.; Chung, W. J.; Choi, Y. H.

2001-01-01

Linear motors can drive a linear motion without intermediate gears, screws or crank shafts. Linear motors can successfully replace ball lead screw in machine tools, because they have a high velocity, acceleration and good positioning accuracy. On the other hand, linear motors emit large amounts of heat and have low efficiency. In this paper, heat sources of a synchronous linear motor with high velocity and force are measured and analyzed. To improve the thermal stiffness of the linear motor, an insulation layer with low thermal conductivity is inserted between cooler and machine table. Some effects of the insulation layer are presented

Lighter touch keeps in the heat. [Advantages of low-thermal-mass insulation

Energy Technology Data Exchange (ETDEWEB)

Pipes, A.

1979-04-01

Low-thermal-mass insulation of ceramic fibers and light refractory materials is more suitable to applications with intermittent processes and lower-temperature melting and retreating, where the heat-retention requirements do not require traditional furnace design. Old furnaces can be retrofitted by replacing bricks with insulation or by veneering. Insulating materials include ceramic, alumina, and quartz fibers, and microtherm in the form of blocks, blankets and other shapes. 4 figures. (DCK)

Propiedades térmicas e hídricas de materiales aislantes apropiadas para fábricas históricas = Thermal and hygric properties of insulation materials suitable for historic fabrics

Directory of Open Access Journals (Sweden)

Rosanne Walker

2016-08-01

Full Text Available Mejorar el rendimiento térmico de los edificios mediante la adaptación del aislamiento puede reducir la pérdida innecesaria de calor y energía minimizando el impacto ambiental. El aislamiento térmico interior es a menudo el elegido en los edificios históricos para preservar sus características. Sin embargo, el aislamiento interior puede aumentar la acumulación de humedad en paredes que socavan su durabilidad. Hay una falta de conocimiento sobre la eficacia de sólidos muros históricos y el impacto del aislamiento interno en su comportamiento higrotérmico. Este artículo investiga las propiedades térmicas e hídricas de siete opciones de aislamiento internos, incluyendo la pintura térmica, aerogel (AG, corcho-cal (CL, cal-cáñamo (HL, silicato de calcio bordo (CSB, tablero de fibra de madera (TFB y placa de polisocianurato (PIR. Sus propiedades se comparan con un enlucido de cal tradicional. El PIR y el aerogel AG muestran extraordinarias propiedades térmicas que contribuyen a la comodidad y ahorro de energía, y la CL y HL son permeables al vapor y a la capilaridad. Estos tienen aproximadamente el doble de la masa térmica de los otros aislantes. Además, la CL tiene una buena inercia térmica (segunda difusividad más baja y, a pesar de su contenido orgánico, una adsorción de baja a alta RH. Abstract Improving the thermal performance of buildings by retrofitting insulation can reduce unnecessary heat loss and building operational energy minimising environmental impact. Internal thermal insulation is often favoured for historic buildings to preserve their features. However, internal insulation may increase moisture accumulation in walls undermining their durability. There is a lack of knowledge on the performance of historic solid walls and the impact of internal insulation in their hygrothermal behaviour. This paper investigates the thermal and hygric properties of seven internal insulation options including thermal paint

Polyimide-Foam/Aerogel Composites for Thermal Insulation

Science.gov (United States)

Williams, Martha; Fesmire, James; Sass, Jared; Smith, Trent; Weoser. Erol

2009-01-01

Composites of specific types of polymer foams and aerogel particles or blankets have been proposed to obtain thermal insulation performance superior to those of the neat polyimide foams. These composites have potential to also provide enhanced properties for vibration dampening or acoustic attenuation. The specific type of polymer foam is denoted "TEEK-H", signifying a series, denoted H, within a family of polyimide foams that were developed at NASA s Langley Research Center and are collectively denoted TEEK (an acronym of the inventors names). The specific types of aerogels include Nanogel aerogel particles from Cabot Corporation in Billerica, MA. and of Spaceloft aerogel blanket from Aspen Aerogels in Northborough, MA. The composites are inherently flame-retardant and exceptionally thermally stable. There are numerous potential uses for these composites, at temperatures from cryogenic to high temperatures, in diverse applications that include aerospace vehicles, aircraft, ocean vessels, buildings, and industrial process equipment. Some low-temperature applications, for example, include cryogenic storage and transfer or the transport of foods, medicines, and chemicals. Because of thermal cycling, aging, and weathering most polymer foams do not perform well at cryogenic temperatures and will undergo further cracking over time. The TEEK polyimides are among the few exceptions to this pattern, and the proposed composites are intended to have all the desirable properties of TEEK-H foams, plus improved thermal performance along with enhanced vibration or acoustic-attenuation performance. A composite panel as proposed would be fabricated by adding an appropriate amount of TEEK friable balloons into a mold to form a bottom layer. A piece of flexible aerogel blanket material, cut to the desired size and shape, would then be placed on the bottom TEEK layer and sandwiched between another top layer of polyimide friable balloons so that the aerogel blanket would become

Thermal conductivity of magnetic insulators with strong spin-orbit coupling

Science.gov (United States)

Stamokostas, Georgios; Lapas, Panteleimon; Fiete, Gregory A.

We study the influence of spin-orbit coupling on the thermal conductivity of various types of magnetic insulators. In the absence of spin-orbit coupling and orbital-degeneracy, the strong-coupling limit of Hubbard interactions at half filling can often be adequately described in terms of a pure spin Hamiltonian of the Heisenberg form. However, in the presence of spin-orbit coupling the resulting exchange interaction can become highly anisotropic. The effect of the atomic spin-orbit coupling, taken into account through the effect of magnon-phonon interactions and the magnetic order and excitations, on the lattice thermal conductivity of various insulating magnetic systems is studied. We focus on the regime of low temperatures where the dominant source of scattering is two-magnon scattering to one-phonon processes. The thermal current is calculated within the Boltzmann transport theory. We are grateful for financial support from NSF Grant DMR-0955778.

Methodology for Thermal Behaviour Assessment of Homogeneous Façades in Heritage Buildings

Directory of Open Access Journals (Sweden)

Enrique Gil

2017-01-01

Full Text Available It is fundamental to study the thermal behaviour in all architectural constructions throughout their useful life, in order to detect early deterioration ensuring durability, in addition to achieving and maintaining the interior comfort with the minimum energy consumption possible. This research has developed a methodology to assess the thermal behaviour of façades in heritage buildings. This paper presents methodology validation and verification (V & V through a laboratory experiment. Guidelines and conclusions are extracted with the employment of three techniques in this experiment (thermal sensors, thermal imaging camera, and 3D thermal simulation in finite element software. A small portion of a homogeneous façade has been reproduced with indoor and outdoor thermal conditions. A closed chamber was constructed with wood panels and thermal insulation, leaving only one face exposed to the outside conditions, with a heat source inside the chamber that induces a temperature gradient in the wall. With this methodology, it is possible to better understand the thermal behaviour of the façade and to detect possible damage with the calibration and comparison of the results obtained by the experimental and theoretical techniques. This methodology can be extrapolated to the analysis of the thermal behaviour of façades in heritage buildings, usually made up of homogeneous material.

Improving thermal insulation of TC4 using YSZ-based coating and SiO2 aerogel

Directory of Open Access Journals (Sweden)

Lei Jin

2015-04-01

Full Text Available In this paper, air plasmas spray (APS was used to prepare YSZ and Sc2O3–YSZ (ScYSZ coating in order to improve the thermal insulation ability of TC4 alloy. SiO2 aerogel was also synthesized and affixed on TC4 titanium alloy to inhabit thermal flow. The microstructures, phase compositions and thermal insulation performance of three coatings were analyzed in detail. The results of thermal diffusivity test by a laser flash method showed that the thermal diffusivities of YSZ, Sc2O3–YSZ and SiO2 aerogel are 0.553, 0.539 and 0.2097×10−6 m2/s, respectively. Then, the thermal insulation performances of three kinds of coating were investigated from 20 °C to 400 °C using high infrared radiation heat flux technology. The experimental results indicated that the corresponding temperature difference between the top TC4 alloy (400 °C and the bottom surface of YSZ is 41.5 °C for 0.6 mm thickness coating. For 1 mm thickness coating, the corresponding temperature difference between the top TC4 alloys (400 °C and the bottom surface of YSZ, ScYSZ, SiO2 aerogel three specimens is 54, 54.6 and 208 °C, respectively. The coating thickness and species were found to influence the heat insulation ability. In these materials, YSZ and ScYSZ exhibited a little difference for heat insulation behavior. However, SiO2 aerogel was the best one among them and it can be taken as protection material on TC4 alloys. In outer space, SiO2 aerogel can meet the need of thermal insulation of TC4 of high-speed aircraft.

Application and feasibility of coal fly ash and scrap tire fiber as wood wall insulation supplements in residential buildings

Energy Technology Data Exchange (ETDEWEB)

Van de Lindt, J.W.; Carraro, J.A.H.; Heyliger, P.R.; Choi, C. [Colorado State University, Department of Civil and Environmental Engineering, Fort Collins, CO (United States)

2008-08-15

Each year, nearly 55% of the fly ash (FA) produced by coal burning power plants in the United States is disposed of in landfills and ash ponds, while the amount of recycled fiber from scrap tires that is beneficially used in end-user markets is virtually negligible. This paper presents the results of a study carried out to investigate whether it might be possible to increase the thermal efficiency of a light-frame residential structure through addition of a fly ash-scrap tire fiber composite to traditional fiberglass insulation in light-frame wood residential construction. This type of construction represents more than 80% of the building stock in North America. The results of this study suggest that the fly ash-scrap tire fiber composite provides a sustainable supplement to traditional insulation that not only increases the efficiency of traditional insulation but can also help significantly reduce the environmental issues associated with disposal of these waste products. (author)

Application and feasibility of coal fly ash and scrap tire fiber as wood wall insulation supplements in residential buildings

International Nuclear Information System (INIS)

Van de Lindt, J.W.; Carraro, J.A.H.; Heyliger, P.R.; Choi, C.

2008-01-01

Each year, nearly 55% of the fly ash (FA) produced by coal burning power plants in the United States is disposed of in landfills and ash ponds, while the amount of recycled fiber from scrap tires that is beneficially used in end-user markets is virtually negligible. This paper presents the results of a study carried out to investigate whether it might be possible to increase the thermal efficiency of a light-frame residential structure through addition of a fly ash-scrap tire fiber composite to traditional fiberglass insulation in light-frame wood residential construction. This type of construction represents more than 80% of the building stock in North America. The results of this study suggest that the fly ash-scrap tire fiber composite provides a sustainable supplement to traditional insulation that not only increases the efficiency of traditional insulation but can also help significantly reduce the environmental issues associated with disposal of these waste products. (author)

External Insulation of Masonry Walls and Wood Framed Walls

Energy Technology Data Exchange (ETDEWEB)

Baker, P. [Building Science Corporation, Somerville, MA (United States)

2013-01-01

The use of exterior insulation on a building is an accepted and effective means to increase the overall thermal resistance of the assembly that also has other advantages of improved water management and often increased air tightness of building assemblies. For thin layers of insulation (1” to 1 ½”), the cladding can typically be attached directly through the insulation back to the structure. For thicker insulation layers, furring strips have been added as a cladding attachment location. This approach has been used in the past on numerous Building America test homes and communities (both new and retrofit applications), and has been proven to be an effective and durable means to provide cladding attachment. However, the lack of engineering data has been a problem for many designers, contractors, and code officials. This research project developed baseline engineering analysis to support the installation of thick layers of exterior insulation on existing masonry and frame walls. Furthermore, water management details necessary to integrate windows, doors, decks, balconies and roofs were created to provide guidance on the integration of exterior insulation strategies with other enclosure elements.

Adaptive thermal comfort for buildings in Portugal based on occupants' thermal perception

Energy Technology Data Exchange (ETDEWEB)

Matias, L.; Pina Santos, C.; Rebelo, M. [LNEC National Laboratory for Civil Engineering, Lisbon (Portugal); Almeida, S. [FCT Foundation for Science and Technology, Lisbon (Portugal); Correia Guedes, M. [IST Higher Technical Inst., Lisbon (Portugal)

2009-07-01

The use of air conditioning systems in Portugal has increased in recent years. Most new service buildings are equipped with mechanical air conditioning systems, either due to commercial reasons, productivity, or due to high internal thermal loads, and solar gains through windows. However, a large percentage of older service buildings are still naturally ventilated. In ASHRAE 55 thermal comfort standard, an adaptive model was adopted as an optional method for determining acceptable thermal conditions in naturally conditioned spaces. Recently, Portugal's National Laboratory for Civil Engineering (LNEC) initiated an interdisciplinary research study in this field. The research team of physicists, social scientists, and civil engineers developed better modeling of adaptive thermal strategies. This paper described the adaptive approach that defined indoor thermal comfort requirements applicable to Portuguese buildings. The study focused on assessing, in real use conditions, indoor environments and the response of occupants of office and educational buildings, and homes for the elderly. The results were obtained from 285 field surveys carried out on 40 buildings and a set of 2367 questionnaires completed by occupants. Field surveys assessed and measured the main indoor environmental parameters during summer, winter and mid-season. This paper included the results of the analysis to the occupants' thermal perception and expectation, by relating them to both measured and collected indoor thermal environments and outdoor climate. The relation between the occupants' thermal sensation and preference was analysed for different types of activities, throughout different seasons. Results showed that occupants may tolerate broader temperature ranges than those indicated in current standards, particularly in the heating season. 10 refs., 3 tabs., 9 figs.

Comparative experimental and numerical studies of usual insulation materials and PCMs in buildings at Casablanca

Science.gov (United States)

Mourid, Amina; El Alami, Mustapha

2018-05-01

In this paper, we present a comparative thermal study of the usual insulation materials used in the building as well as the innovate one like phase change materials (PCMs). Both experimental study and numerical approach were applied in this work for summer season. In the experimental study the PCM was installed on the outer surface on the ceiling of one of two full-scale rooms located at FSAC, Casablanca. A simulation model was performed with TRNSYS’17 software. We have established as a criterion of comparison the internal temperatures. An economic study also has been carried out. Based on this latter, that the PCM is most efficient.

Improving thermal insulation of TC4 using YSZ-based coating and SiO2 aerogel

OpenAIRE

Jin, Lei; Li, Peizhong; Zhou, Haibin; Zhang, Wei; Zhou, Guodong; Wang, Chun

2015-01-01

In this paper, air plasmas spray (APS) was used to prepare YSZ and Sc2O3–YSZ (ScYSZ) coating in order to improve the thermal insulation ability of TC4 alloy. SiO2 aerogel was also synthesized and affixed on TC4 titanium alloy to inhabit thermal flow. The microstructures, phase compositions and thermal insulation performance of three coatings were analyzed in detail. The results of thermal diffusivity test by a laser flash method showed that the thermal diffusivities of YSZ, Sc2O3–YSZ and SiO2...

The experiment study of the thermal insulation of the roof-slab of the main vessel of a LMFBR

International Nuclear Information System (INIS)

Wang Zhifeng; Wang Zhou; Yang Xianyong

1995-01-01

The effects of composition of insulation, i.e., reflective multi-plate thermal insulator, protecting the roof-slab of the vessel of the LMFBR on the heat transfer performance has been studied experimentally for CEFR. A economical form of the thermal insulation is suggested for CEFR. In addition, the scheme without reflective thermal insulator which has only a forced convection cooling system has been studied experimentally and a formula to calculate the average Nusselt number of the flow channel, which is valuable for CEFR design, has been raised

Timber Chips as the Insulation Material for Energy Saving in Prefabricated Offices

Directory of Open Access Journals (Sweden)

Yupeng Wang

2016-06-01

Full Text Available This research demonstrates the feasibility of a roof insulation method for prefabricated offices that uses vinyl packed timber chips to reduce air conditioning loads (hereinafter referred to as AC loads and which also improves indoor thermal comfort. The advantages of the new roof insulation method were revealed through comparing the impacts of four roof types on prefabricated offices. The AC load and indoor thermal comfort (surface temperature and air temperature were evaluated. The disposal of scrap timber discarded from building construction projects is costing money, and is also a waste of natural resources. The assessment of a new roof insulation method with timber chips demonstrates the advanced usage of timber chips, reducing the environmental load in the building construction process. On the other hand, since prefabricated offices have lower thermal storage capacities and are less airtight than RC (reinforced concrete or S (steel structured buildings, the AC load consumption and indoor thermal comfort exacerbation in prefabricated offices is more serious. Especially in summer, a large amount of solar energy absorption from the roof raises the indoor air temperature and significantly increases the cooling load. This research contributes to the environmental design for prefabricated offices, and develops a method for the reuse of wood chips.

Understanding the thermal, mechanical and electrical properties of epoxy nanocomposites

International Nuclear Information System (INIS)

Sarathi, R.; Sahu, R.K.; Rajeshkumar, P.

2007-01-01

In the present work, the electrical, mechanical and thermal properties of epoxy nanocomposite materials were studied. The electrical insulation characteristics were analyzed through short time breakdown voltage test, accelerated electrical ageing test, and by tracking test. The breakdown voltage increases with increase in nano-clay content up to 5 wt%, under AC and DC voltages. The volume resistivity, permittivity and tan(δ) of the epoxy nanocomposites were measured. The Weibull studies indicate that addition of nanoclay upto 5 wt% enhances the characteristic life of epoxy nanocomposite insulation material. The tracking test results indicate that the tracking time is high with epoxy nanocomposites as compared to pure epoxy. Ageing studies were carried out to understand the surface characteristic variation through contact angle measurement. The hydrophobicity of the insulating material was analysed through contact angle measurement. The diffusion coefficients of the material with different percentage of clay in epoxy nanocomposites were calculated. The exfoliation characteristics in epoxy nanocomposites were analyzed through wide angle X-ray diffraction (WAXD) studies. The thermal behaviour of the epoxy nanocomposites was analyzed by carrying out thermo gravimetric-differential thermal analysis (TG-DTA) studies. Heat deflection temperature of the material was measured to understand the stability of the material for intermittent temperature variation. The dynamic mechanical analysis (DMA) results indicated that storage modulus of the material increases with small amount of clay in epoxy resin. The activation energy of the material was calculated from the DMA results

Description and characterization of systems for external insulation and retrofitting for Denmark with emphasis on the thermal performance

DEFF Research Database (Denmark)

Rudbeck, Claus Christian; Svendsen, Sv Aa Højgaard

1998-01-01

Lately there has been quite a large focus on retrofitting of the Danish buildings. The retrofitting of the building is done in order to solve one or more of the following problems: bad indoor climate, large use of energy for heating, insufficient durability or architectural unsatisfactory.In order...... to solve these problems insulation is often part of the retrofitting. As internal insulation has many disadvantages with regards to heat and moisture only systems for external insulation will be mentioned here.As there are several different systems for external insulation, each with different properties......, there is a need for a systematic approach when the building designer chooses which system should be used on the building which is to be retrofitted....

Tunable metal-insulator transitions in bilayer graphene by thermal annealing

OpenAIRE

Kalon, Gopinadhan; Shin, Young Jun; Yang, Hyunsoo

2012-01-01

Tunable and highly reproducible metal-insulator transitions have been observed in bilayer graphene upon thermal annealing at 400 K under high vacuum conditions. Before annealing, the sample is metallic in the whole temperature regime of study. Upon annealing, the conductivity changes from metallic to that of an insulator and the transition temperature is a function of annealing time. The pristine metallic state can be reinstated by exposing to air thereby inducing changes in the electronic pr...

Handbook of Thermal Insulation Applications.

Science.gov (United States)

1983-01-01

Wiuppuoror *tIe beamsWiefag ln~ td ~oair ilmstool beams Plate 18. Metal Building Ceilings - A 18b: Fir* hataird rathge may limit the use of foam Insulation...RFCTANGUI.AR SOL TD A = 2(WxL+LxH+HxW) B V = WxLxH H L TRAPEZOID A 2 (A + B) x H A CONE A -n xRxS+ i xR 2 B V =( /3)x R2 x H TRIANGLE A BxH A- 2 CYLI NDER H 2...FABRICATIIG RECTANGULAR HEATING AND COOLING DUCTWORK. FIBERGLAS DUCT BOARD OWENS-CORNING FIBERGLAS CORP GLASS FIBER RIGID BOARD WITH ALUMINUM 4bD FOIL VAPOR

Electrically and Thermally Insulated Joint for Liquid Nitrogen Transfer

DEFF Research Database (Denmark)

Rasmussen, Carsten; Jensen, Kim Høj; Holbøll, Joachim T.

1999-01-01

A prototype of a superconducting cable is currently under construction. The cable conductor is cooled by liquid nitrogen in order to obtain superconductivity. The peripheral cooling circuit is kept at ground potential. This requires a joint which insulates both electrically and thermally...

Climate Chamber Experiment-Based Thermal Analysis and Design Improvement of Traditional Huizhou Masonry Walls

Directory of Open Access Journals (Sweden)

Ling Dong

2018-03-01

Full Text Available Supported by thousands of years of history, traditional Huizhou buildings have played a vital role, both functionally and culturally, as residential buildings in China. Masonry walls are one of the key building components of a Huizhou building; however, the traditional Huizhou masonry wall structure, predominantly a hollow brick structure, cannot meet the local building energy code requirements, and thus needs to be improved. Within this context, the present research measures the actual thermal performance of traditional Huizhou masonry walls for historical buildings and new-built buildings, which results in mean thermal transmittances of 1.892 W/m2·K and 2.821 W/m2·K, respectively, while the local building energy code requires a minimum thermal transmittance of 1.500 W/m2·K. In order to improve the thermal performance of traditional Huizhou masonry walls, four design scenarios for wall insulation are proposed and tested in a climate chamber: (1 hollow brick wall with inorganic interior insulation mortar, (2 solid brick wall with inorganic interior insulation mortar, (3 hollow brick wall with foamed concrete, and (4 hollow brick wall with foamed concrete plus inorganic interior insulation mortar. The experiment results indicate that, among the four proposed design scenarios, only scenario 4 can significantly improve the thermal performance of Huizhou masonry walls and meet the building energy code requirements, with a mean thermal transmittance of 1.175 W/m2·K. This research lays the foundation for improving the thermal performance of Huizhou masonry walls with new insulation and construction technology, thereby helping to improve the quality of life of Huizhou residents while respecting the cultural significance of the traditional Huizhou building.

Relationship of Cure Temperature to Mechanical, Physical, and Dielectric Performance of PDMS Glass Composite for Electric Motor Insulation

Science.gov (United States)

Miller, Sandi G.; Becker, Kathleen; Williams, Tiffany S.; Scheiman, Daniel A.; McCorkle, Linda S.; Heimann, Paula J.; Ring, Andrew; Woodworth, Andrew

2017-01-01

Achieving NASAs aggressive fuel burn and emission reduction for N-plus-3 aircraft will require hybrid electric propulsion system in which electric motors driven by either power generated from turbine or energy storage system will power the fan for propulsion. Motors designed for hybrid electric aircraft are expected to operate at medium to high voltages over long durations in a high altitude service environment. Such conditions have driven research toward the development of wire insulation with improved mechanical strength, thermal stability and increased breakdown voltage. The silicone class of materials has been considered for electric wire insulation due to its inherent thermal stability, dielectric strength and mechanical integrity. This paper evaluates the dependence of these properties on the cure conditions of a polydimethyl-siloxane (PDMS) elastomer; where both cure temperature and base-to-catalyst ratio were varied. The PDMS elastomer was evaluated as a bulk material and an impregnation matrix within a lightweight glass veil support. The E-glass support was selected for mechanical stiffness and dielectric strength. This work has shown a correlation between cure conditions and material physical properties. Tensile strength increased with cure temperature whereas breakdown voltage tended to be independent of process variations. The results will be used to direct material formulation based on specific insulation requirements.

A novel highly porous ceramic foam with efficient thermal insulation and high temperature resistance properties fabricated by gel-casting process

Science.gov (United States)

Yu, Jiahong; Wang, Guixiang; Tang, Di; Qiu, Ya; Sun, Nali; Liu, Wenqiao

2018-01-01

The design of super thermal insulation and high-temperature resistant materials for high temperature furnaces is crucial due to the energy crisis and the huge wasting. Although it is told that numerous studies have been reported about various of thermal insulation materials prepared by different methods, the applications of yttria-stabilized zirconia (YSZ) ceramic foams fabricated through tert-butyl alcohol (TBA)-based gel-casting process in bulk thermal isolators were barely to seen. In this paper, highly porous yttria-stabilized zirconia (YSZ) ceramic foams were fabricated by a novel gel-casting method using tert-butyl alcohol (TBA) as solvent and pore-forming agent. Different raw material ratio, sintering temperature and soaking time were all investigated to achieve optimal thermal insulation and mechanical properties. We can conclude that porosity drops gradually while compressive strength increases significantly with the rising temperature from 1000-1500°C. With prolonged soaking time, there is no obvious change in porosity but compressive strength increases gradually. All specimens have uniformly distributed pores with average size of 0.5-2μm and show good structural stability at high temperature. The final obtained ceramic foams displayed an outstanding ultra-low thermal conductivity property with only 200.6 °C in cold surface while the hot side was 1000 °C (hold 60 min to keep thermal balance before testing) at the thickness of 10 mm.

Mechanisms of natural ventilation in livestock buildings

DEFF Research Database (Denmark)

Rong, Li; Bjerg, Bjarne; Batzanas, Thomas

2016-01-01

Studies on the mechanisms of natural ventilation in livestock buildings are reviewed and influences on discharge and pressure coefficients are discussed. Compared to studies conducted on buildings for human occupation and industrial buildings which focus on thermal comfort, ventilation systems......, indoor air quality, building physics and energy etc., our understanding of the mechanisms involved in natural ventilation of livestock buildings are still limited to the application of the orifice equation. It has been observed that the assumptions made for application of the orifice equation...... are not valid for wind-induced cross ventilation through large openings. This review identifies that the power balance model, the concept of stream tube and the local dynamic similarity model has helped in the fundamental understanding of wind-induced natural ventilation in buildings for human occupation...

Workshop on technical assessment of industrial thermal insulation materials: summary

International Nuclear Information System (INIS)

Peterson, S.

1976-07-01

Over 80 participants representing 50 organizations met to discuss the report, Industrial Thermal Insulation--An Assessment, ORNL/TM-5283. Presentations on the performance of available materials, economic considerations, and measurement problems were followed by discussion. A final wrap-up session concluded that the report was valuable in pointing the direction for needed effort in the area, confirmed the indicated actions needed to further industrial application of insulation, and called for future meetings to continue the dialogue between the various facets of the industry

SUPER-CAPACITOR APPLICATION IN ELECTRICAL POWER CABLE TESTING FACILITIES IN THERMAL ENDURANCE AND MECHANICAL BRACING TESTS

Directory of Open Access Journals (Sweden)

I. V. Oleksyuk

2015-01-01

Full Text Available The current-carrying cores of the electrical power cables should be resistant to effects of short-circuit currents whose values depend on the material of the core, its cross-sectional area, cable insulation properties, environment temperature, and the duration of the short-circuit current flow (1 and 3–4 sec. when tested for thermal endurance and mechanical bracing. The facilities for testing the 10 kV aluminum core cables with short-circuit current shall provide mechanical-bracing current 56,82 kA and thermal endurance current 11,16 kA. Although capacitors provide such values of the testing currents to the best advantage, utilizing conventional capacitor-units will involve large expenditures for erecting and  running a separate building. It is expedient to apply super-capacitors qua the electric power supply for testing facilities, as they are capacitors with double-electrical layer and involve the current values of tens of kilo-amperes.The insulation voltage during short-circuit current testing being not-standardized, it is not banned to apply voltages less than 10 kV when performing short-circuit thermal endurance and mechanical bracing tests for electrical power cables of 10 kV. The super-capacitor voltage variation-in-time graph consists of two regions: capacitive and resistive. The capacitive part corresponds to the voltage change consequent on the energy change in the super-capacitors. The resistive part shows the voltage variation due to the active resistance presence in the super-capacitor.The author offers the algorithm determining the number of super capacitors requisite for testing 10 kV-electrical power cables with short-circuit currents for thermal endurance and mechanical bracing. The paper shows that installation of super-capacitors in the facilities testing the cables with short-circuit currents reduces the area needed for the super-capacitors in comparison with conventional capacitors more than by one order of magnitude.

The homeostasis solution – Mechanical homeostasis in architecturally homeostatic buildings

International Nuclear Information System (INIS)

Wang, Lin-Shu; Ma, Peizheng

2016-01-01

Highlights: • Architectural homeostatic buildings (AHBs) make sense because of the laws of physics. • However, high efficiency can be obtained only with AHBs and equipment considered as systems. • Mechanical homeostasis facilitates AHB-equipment system synergy with heat extraction. • Entropically speaking a building needs neither energy nor a fixed amount of heat, but its homeostatic existence. • Homeostatic buildings can reduce building energy consumption from 80% to 90%. - Abstract: We already know, for energy-saving potential, the necessary architectural features in well-designed buildings: high performance building envelope, sufficient interior thermal mass, and hydronic-network activated radiant surfaces for cooling and heating. Buildings with these features may be referred to as architecturally homeostatic buildings (AHBs); such a building-system is thermally semi-autonomous in the sense that its temperature variation stays within a certain range even without conditioning equipment, and, with conditioning equipment in operation, its thermal regulation is handled by its hydronic heat-distribution-network for controlling the temperature level of the building. At the present time conventional HVAC equipment is used for maintaining the heat-distribution-network: this arrangement, however, has resulted in great energy saving only for AHBs with accessible natural water bodies. In operation of general AHBs, a case is made here for a new kind of mechanical equipment having the attribute of mechanical homeostasis (MH). MH is a new energy transformation concept in a triadic framework. Superlative energy efficiency is predicted as a result of combined improvements in higher triadCOPs and lower total (inducted + removed) heat rates—evincing existence of synergy in architectural and mechanical homeostasis, which together will be referred to as the homeostasis solution.

Concerning the sound insulation of building elements made up of light concretes. [acoustic absorption efficiency calculations

Science.gov (United States)

Giurgiu, I. I.

1974-01-01

The sound insulating capacity of building elements made up of light concretes is considered. Analyzing differentially the behavior of light concrete building elements under the influence of incident acoustic energy and on the basis of experimental measurements, coefficients of correction are introduced into the basic formulas for calculating the sound insulating capacity for the 100-3,2000 Hz frequency band.

Extreme temperature stability of thermally insulating graphene-mesoporous-silicon nanocomposite

Science.gov (United States)

Kolhatkar, Gitanjali; Boucherif, Abderraouf; Rahim Boucherif, Abderrahim; Dupuy, Arthur; Fréchette, Luc G.; Arès, Richard; Ruediger, Andreas

2018-04-01

We demonstrate the thermal stability and thermal insulation of graphene-mesoporous-silicon nanocomposites (GPSNC). By comparing the morphology of GPSNC carbonized at 650 °C as-formed to that after annealing, we show that this nanocomposite remains stable at temperatures as high as 1050 °C due to the presence of a few monolayers of graphene coating on the pore walls. This does not only make this material compatible with most thermal processes but also suggests applications in harsh high temperature environments. The thermal conductivity of GPSNCs carbonized at temperatures in the 500 °C-800 °C range is determined through Raman spectroscopy measurements. They indicate that the thermal conductivity of the composite is lower than that of silicon, with a value of 13 ± 1 W mK-1 at room temperature, and not affected by the thin graphene layer, suggesting a role of the high concentration of carbon related-defects as indicated by the high intensity of the D-band compared to G-band of the Raman spectra. This morphological stability at high temperature combined with a high thermal insulation make GPSNC a promising candidate for a broad range of applications including microelectromechanical systems and thermal effect microsystems such as flow sensors or IR detectors. Finally, at 120 °C, the thermal conductivity remains equal to that at room temperature, attesting to the potential of using our nanocomposite in devices that operate at high temperatures such as microreactors for distributed chemical conversion, solid oxide fuel cells, thermoelectric devices or thermal micromotors.

Thermal Jacket Design Using Cellulose Aerogels for Heat Insulation Application of Water Bottles

Directory of Open Access Journals (Sweden)

Hai M. Duong

2017-11-01

Full Text Available Thermal jacket design using eco-friendly cellulose fibers from recycled paper waste is developed in this report. Neoprene as an outmost layer, cellulose aerogels in the middle and Nylon as an innermost layer can form the best sandwiched laminate using the zigzag stitching method for thermal jacket development. The temperature of the ice slurry inside the water bottle covered with the designed thermal jackets remains at 0.1 °C even after 4 h, which is the average duration of an outfield exercise. Interestingly, the insulation performance of the designed thermal jackets is much better than the commercial insulated water bottles like FLOE bottles and is very competition to that of vacuum flasks for a same period of 4 h and ambient conditions.

High sensitivity thermal sensors on insulating diamond

Energy Technology Data Exchange (ETDEWEB)

Job, R. [Fernuniversitaet Hagen (Gesamthochschule) (Germany). Electron. Devices; Denisenko, A.V. [Fernuniversitaet Hagen (Gesamthochschule) (Germany). Electron. Devices; Zaitsev, A.M. [Fernuniversitaet Hagen (Gesamthochschule) (Germany). Electron. Devices; Melnikov, A.A. [Belarussian State Univ., Minsk (Belarus). HEII and FD; Werner, M. [VDI/VDE-IT, Teltow (Germany); Fahrner, W.R. [Fernuniversitaet Hagen (Gesamthochschule) (Germany). Electron. Devices

1996-12-15

Diamond is a promising material to develop sensors for applications in harsh environments. To increase the sensitivity of diamond temperature sensors the effect of thermionic hole emission (TE) over an energetic barrier formed in the interface between highly boron-doped p-type and intrinsic insulating diamond areas has been suggested. To study the TE of holes a p-i-p diode has been fabricated and analyzed by electrical measurements in the temperature range between 300 K and 700 K. The experimental results have been compared with numerical simulations of its electrical characteristics. Based on a model of the thermionic emission of carriers into an insulator it has been suggested that the temperature sensitivity of the p-i-p diode on diamond is strongly affected by the re-emission of holes from a group of donor-like traps located at a level of 0.7-1.0 eV above the valence band. The mechanism of thermal activation of the current includes a spatial redistribution of the potential, which results in the TE regime from a decrease of the immobilized charge of the ionized traps within the i-zone of the diode and the correspondent lowering of the forward biased barrier. The characteristics of the p-i-p diode were studied with regard to temperature sensor applications. The temperature coefficient of resistance (TCR=-0.05 K{sup -1}) for temperatures above 600 K is about four times larger than the maximal attainable TCR for conventional boron-doped diamond resistors. (orig.)

ANALYSIS OF THERMAL PROPERTIES AND HEAT LOSS IN CONSTRUCTION AND ISOTHERMAL MATERIALS OF MULTILAYER BUILDING WALLS

Directory of Open Access Journals (Sweden)

Arkadiusz Urzędowski

2017-06-01

Full Text Available The article discusses the impact of vertical partition, technology on thermal insulation of the building, and the resulting savings and residents thermal comfort. The study is carried out as an analysis of three selected design solutions including such materials as: aerated concrete elements, polystyrene, ceramic elements, concrete, mineral plaster. Simulation results of heat transfer in a multi-layered wall, are subjected to detailed analysis by means of thermal visual methods. The study of existing structures, helped to identify the local point of heat loss by means of infrared technology leading to determination of U-value reduction by 36% in maximum for the described 3 types of structure.

Building materials and systems with vacuum insulation panels for external walls; Bauelemente und Systeme mit VIP fuer Aussenwandkonstruktionen - Schlussbericht

Energy Technology Data Exchange (ETDEWEB)

Binz, A; Steinke, G

2007-07-01

This final report for the Swiss Federal Office of Energy (SFOE) takes a look at materials and systems using vacuum insulation panels (VIP) for the construction of external walls. The aim of this research project was the development, practical use and market introduction of VIP systems that take account of the special properties of VIP. Along with partners in industry, applications involving external and internal insulation were examined. The need for protecting the vacuum panels against mechanical damage is stressed. The specific needs for the protection of external and internal applications are discussed. The dynamic developments in this relatively new area are commented on. Various mounting systems are examined and commented on. The thermal properties of such insulation systems and applications are noted and commented on.

Mechanisms of thermally induced threshold voltage instability in GaN-based heterojunction transistors

International Nuclear Information System (INIS)

Yang, Shu; Liu, Shenghou; Liu, Cheng; Lu, Yunyou; Chen, Kevin J.

2014-01-01

In this work, we attempt to reveal the underlying mechanisms of divergent V TH -thermal-stabilities in III-nitride metal-insulator-semiconductor high-electron-mobility transistor (MIS-HEMT) and MOS-Channel-HEMT (MOSC-HEMT). In marked contrast to MOSC-HEMT featuring temperature-independent V TH , MIS-HEMT with the same high-quality gate-dielectric/III-nitride interface and similar interface trap distribution exhibits manifest thermally induced V TH shift. The temperature-dependent V TH of MIS-HEMT is attributed to the polarized III-nitride barrier layer, which spatially separates the critical gate-dielectric/III-nitride interface from the channel and allows “deeper” interface trap levels emerging above the Fermi level at pinch-off. This model is further experimentally validated by distinct V G -driven Fermi level movements at the critical interfaces in MIS-HEMT and MOSC-HEMT. The mechanisms of polarized III-nitride barrier layer in influencing V TH -thermal-stability provide guidelines for the optimization of insulated-gate III-nitride power switching devices

Thermal insulation with glazings and windows. Implementation of requirements and outlook on future development; Waermeschutz mit Verglasungen und Fenstern. Umsetzung der Anforderungen und Ausblick auf Weiterentwicklung

Energy Technology Data Exchange (ETDEWEB)

Froelich, H. [Institut fuer Fenstertechnik e.V., Rosenheim (Germany)

1997-06-01

In the past, windows and glazings were often considered as being a weak point as regards thermal insulation in the external envelope of a building. Increasing demands on thermal insulation in construction have been seen as a challenge by all those involved. The development of new glazings and of improved frames made it possible to use large sized windows and glazed facade elements even after the new Heat Loss Regulation (Waermeschutzverordnung) dated 1st January 1995 came into effect. In this connection, the possible consideration of energy gain from the outside via transparent building elements is very important. The individual components of windows, window elements and light facades such as frames, glazings, panels and additional components e.g. roller shutters have to be designed very precisely now. Apart from thermal properties the other criteria such as fire resistance, sound insulation, solar protection and safety have to be taken into account. The new Building Regulations of the Laender (Landesbauordnung) and the Building Products Regulation (Bauregelliste) of the Deutsches Institut fuer Bautechnik regulate which evidence of usability and conformity are necessary for the various building products such as frame, glass, window, roller shutter, radiator guards, etc. For the time being, it is still mainly referred to national regulations. In future, an increasing number of European standards will be completed and also implemented. There will also be some decisive changes as regards windows and glazings. To a larger extent the effects of thermal bridges will be taken into account. For determining thermal properties there increasingly exists the possibility of carrying out calculations. As regards thermal insulation today, windows and glazings are highly developed building products when correctly designed and manufactured. These building products enable energy saving construction also of large sized dimensions. (orig.) [Deutsch] Fenster und Verglasungen wurden in

The Effect of Passive Design Strategies on Thermal Performance of Female Secondary School Buildings during Warm Season in Hot Dry Climate

Directory of Open Access Journals (Sweden)

Sahar eZahiri

2016-03-01

Full Text Available This paper describes a series of field studies and simulation analysis to improve the thermal performance of school buildings in the city of Tehran in Iran during warm season. The field studies used on-site measurement and questionnaire-based survey in the warm spring season in a typical female secondary school building. The on-site monitoring assessed the indoor air temperature and humidity levels of six classrooms while the occupants completed questionnaires covering their thermal sensations and thermal preferences. Moreover, thermal simulation analysis was also carried out to evaluate and improve the thermal performance of the classrooms based on the students’ thermal requirements and passive design strategies. In this study, the environmental design guidelines for female secondary school buildings were introduced for the hot and dry climate of Tehran, using passive design strategies. The study shows that the application of passive design strategies including south and south-east orientation, 10cm thermal insulation in wall and 5cm in the roof, and the combination of 30cm side fins and overhangs as a solar shading devices, as well as all-day ventilation strategy and the use of thermal mass materials with 25cm-30cm thickness, has considerable impact on indoor air temperatures in warm season in Tehran and keeps the indoor environment in an acceptable thermal condition. The results of the field studies also indicated that most of the occupants found their thermal environment not to be comfortable and the simulation results showed that passive design techniques had a significant influence on the indoor air temperature and can keep it in an acceptable range based on the female students’ thermal requirement. Therefore, in order to enhance the indoor environment and to increase the learning performance of the students, it is necessary to use the appropriate passive design strategies, which also reduce the need for mechanical systems and

Bio-based polyurethane foams toward applications beyond thermal insulation

International Nuclear Information System (INIS)

Gama, Nuno V.; Soares, Belinda; Freire, Carmen S.R.; Silva, Rui; Neto, Carlos P.; Barros-Timmons, Ana; Ferreira, Artur

2015-01-01

Highlights: • Coffee grounds wastes were successfully liquefied yielding a bio-based polyol. • Coffee grounds derived foams formulations were optimized by tuning reagents’ contents. • The viscoelastic properties of these foams are promising to expand their applications. - Abstract: In this work the preparation of viscoelastic bio-based polyurethane foams (PUFs) using polyols obtained via acid liquefaction of coffee grounds wastes has been optimized. In a first stage, the effect of different ratios of isocyanate content to hydroxyl number (0.6, 0.7 and 0.8) and of three distinct percentages of catalyst (3%, 5% and 7%) on the extent of the polymerization reaction was studied by infrared spectroscopy. Next, different percentages of surfactant (14%, 16% and 18%) and blowing agent (12%, 14% and 16%) were used to assess their effect on the density, thermal conductivity and mechanical properties of the foams, including their recovery time. The mechanical properties of the ensuing foams proved to be very interesting due to their viscoelastic behavior. PUFs were also characterized by scanning electron microscopy (SEM) revealing a typical cellular structure and by thermogravimetric analysis (TGA) which proved that these materials are thermally stable up to 190 °C. These results suggest other potential applications for these materials beyond heat insulation in areas where damping properties can be an added value

Compact gas-insulated transformer. Fourteenth quarterly report

Energy Technology Data Exchange (ETDEWEB)

1983-08-01

Objective is to develop a compact, more efficient, quieter transformer which does not rely on mineral oil insulation. Compressed SF/sub 6/ is used as the external insulation and polymer film as the insulation between turns. A separate liquid cooling system is also provided. This document reports progress made in design, mechanical, dielectric, short circuit, thermal, materials, prototype, accessories, commercialization, and system studies. (DLC)

Insulating Foams Save Money, Increase Safety

Science.gov (United States)

2009-01-01

Scientists at Langley Research Center created polyimide foam insulation for reusable cryogenic propellant tanks on the space shuttle. Meanwhile, a small Hialeah, Florida-based business, PolyuMAC Inc., was looking for advanced foams to use in the customized manufacturing of acoustical and thermal insulation. The company contacted NASA, licensed the material, and then the original inventors worked with the company's engineers to make a new material that was better for both parties. The new version, a high performance, flame retardant, flexible polyimide foam, is used for insulating NASA cryogenic propellant tanks and shows promise for use on watercraft, aircraft, spacecraft, electronics and electrical products, automobiles and automotive products, recreation equipment, and building and construction materials.

Reduction of heat insulation upon soaking of the insulation layer

Science.gov (United States)

Achtliger, J.

1983-09-01

Improved thermal protection of hollow masonry by introduction of a core insulation between the inner and outer shell is discussed. The thermal conductivity of insulation materials was determined in dry state and after soaking by water with different volume-related moisture contents. The interpolated thermal conductivity values from three measured values at 10 C average temperature are presented as a function of the pertinent moisture content. Fills of expanded polystyrene, perlite and granulated mineral fibers, insulating boards made of mineral fibers and in situ cellular plastics produced from urea-formaldehyde resin were investigated. Test results show a confirmation of thermal conductivity values for insulating materials in hollow masonry.

Requirements for thermal insulation on prestressed concrete reactor vessels

International Nuclear Information System (INIS)

Neylan, A.J.; Wistrom, J.D.

1979-01-01

During the past decade, extensive design, construction, and operating experience on concrete pressure vessels for gas-cooled reactor applications has accumulated. Excellent experience has been obtained to date on the structural components (concrete, prestressing systems, liners, penetrations, and closures) and the thermal insulation. Three fundamentally different types of insulation systems have been employed to ensure the satisfactory performance of this component, which is critical to the overall success of the prestressed concrete reactor vessel (PCRV). Although general design criteria have been published, the requirements for design, materials, and construction are not rigorously addressed in any national or international code. With the more onerous design conditions being imposed by advanced reactor systems, much greater attention has been directed to advance the state of the art of insulation systems for PCRVs. This paper addresses some of the more recent developments in this field being performed by General Atomic Company and others. (author)

Thermal Performance of Cryogenic Multilayer Insulation at Various Layer Spacings

Science.gov (United States)

Johnson, Wesley Louis

2010-01-01

Multilayer insulation (MLI) has been shown to be the best performing cryogenic insulation system at high vacuum (less that 10 (exp 3) torr), and is widely used on spaceflight vehicles. Over the past 50 years, many investigations into MLI have yielded a general understanding of the many variables that are associated with MLI. MLI has been shown to be a function of variables such as warm boundary temperature, the number of reflector layers, and the spacer material in between reflectors, the interstitial gas pressure and the interstitial gas. Since the conduction between reflectors increases with the thickness of the spacer material, yet the radiation heat transfer is inversely proportional to the number of layers, it stands to reason that the thermal performance of MLI is a function of the number of layers per thickness, or layer density. Empirical equations that were derived based on some of the early tests showed that the conduction term was proportional to the layer density to a power. This power depended on the material combination and was determined by empirical test data. Many authors have graphically shown such optimal layer density, but none have provided any data at such low densities, or any method of determining this density. Keller, Cunnington, and Glassford showed MLI thermal performance as a function of layer density of high layer densities, but they didn't show a minimal layer density or any data below the supposed optimal layer density. However, it was recently discovered that by manipulating the derived empirical equations and taking a derivative with respect to layer density yields a solution for on optimal layer density. Various manufacturers have begun manufacturing MLI at densities below the optimal density. They began this based on the theory that increasing the distance between layers lowered the conductive heat transfer and they had no limitations on volume. By modifying the circumference of these blankets, the layer density can easily be

Control performances of a piezoactuator direct drive valve system at high temperatures with thermal insulation

Science.gov (United States)

Han, Yung-Min; Han, Chulhee; Kim, Wan Ho; Seong, Ho Yong; Choi, Seung-Bok

2016-09-01

This technical note presents control performances of a piezoactuator direct drive valve (PDDV) operated at high temperature environment. After briefly discussing operating principle and mechanical dimensions of the proposed PDDV, an appropriate size of the PDDV is manufactured. As a first step, the temperature effect on the valve performance is experimentally investigated by measuring the spool displacement at various temperatures. Subsequently, the PDDV is thermally insulated using aerogel and installed in a large-size heat chamber in which the pneumatic-hydraulic cylinders and sensors are equipped. A proportional-integral-derivative feedback controller is then designed and implemented to control the spool displacement of the valve system. In this work, the spool displacement is chosen as a control variable since it is directly related to the flow rate of the valve system. Three different sinusoidal displacements with different frequencies of 1, 10 and 50 Hz are used as reference spool displacement and tracking controls are undertaken up to 150 °C. It is shown that the proposed PDDV with the thermal insulation can provide favorable control responses without significant tracking errors at high temperatures.

Internal Insulation of Masonry Walls with Wooden Floor Beams in Northern Humid Climate

DEFF Research Database (Denmark)

Morelli, Martin; Scheffler, Gregor Albrecht; Nielsen, Toke Rammer

2010-01-01

Multi-story buildings in Denmark from 1850–1950 are built with masonry walls and wooden floor beams. Large energy savings can be achieved by insulating the facades. Often interior insulation is the only possibility in order to keep the appearance of the external facade. The internal insulation...... reduces the drying potential of the wall, which might lead to moisture problems in the beam ends embedded in the masonry due to absorption of driving rain. This paper describes a solution to avoid the moisture problems and still achieve large energy savings. The thermal analyses are made in thermal...

Translucent insulating building envelope

DEFF Research Database (Denmark)

Rahbek, Jens Eg

1997-01-01

A new type of translucent insulating material has been tested. This material is made of Celulose-Acetat and have a honey-comb structure. The material has a high solar transmittance and is highly insulating. The material is relatively cheap to produce. Danish Title: Translucent isolerende klimaskærm....

Bionics in textiles: flexible and translucent thermal insulations for solar thermal applications.

Science.gov (United States)

Stegmaier, Thomas; Linke, Michael; Planck, Heinrich

2009-05-13

Solar thermal collectors used at present consist of rigid and heavy materials, which are the reasons for their immobility. Based on the solar function of polar bear fur and skin, new collector systems are in development, which are flexible and mobile. The developed transparent heat insulation material consists of a spacer textile based on translucent polymer fibres coated with transparent silicone rubber. For incident light of the visible spectrum the system is translucent, but impermeable for ultraviolet radiation. Owing to its structure it shows a reduced heat loss by convection. Heat loss by the emission of long-wave radiation can be prevented by a suitable low-emission coating. Suitable treatment of the silicone surface protects it against soiling. In combination with further insulation materials and flow systems, complete flexible solar collector systems are in development.

Insulation Cork Boards—Environmental Life Cycle Assessment of an Organic Construction Material

Science.gov (United States)

Silvestre, José D.; Pargana, Nuno; de Brito, Jorge; Pinheiro, Manuel D.; Durão, Vera

2016-01-01

Envelope insulation is a relevant technical solution to cut energy consumption and reduce environmental impacts in buildings. Insulation Cork Boards (ICB) are a natural thermal insulation material whose production promotes the recycling of agricultural waste. The aim of this paper is to determine and evaluate the environmental impacts of the production, use, and end-of-life processing of ICB. A “cradle-to-cradle” environmental Life Cycle Assessment (LCA) was performed according to International LCA standards and the European standards on the environmental evaluation of buildings. These results were based on site-specific data and resulted from a consistent methodology, fully described in the paper for each life cycle stage: Cork oak tree growth, ICB production, and end-of-life processing-modeling of the carbon flows (i.e., uptakes and emissions), including sensitivity analysis of this procedure; at the production stage—the modeling of energy processes and a sensitivity analysis of the allocation procedures; during building operation—the expected service life of ICB; an analysis concerning the need to consider the thermal diffusivity of ICB in the comparison of the performance of insulation materials. This paper presents the up-to-date “cradle-to-cradle” environmental performance of ICB for the environmental categories and life-cycle stages defined in European standards. PMID:28773516

Insulation Cork Boards-Environmental Life Cycle Assessment of an Organic Construction Material.

Science.gov (United States)

Silvestre, José D; Pargana, Nuno; de Brito, Jorge; Pinheiro, Manuel D; Durão, Vera

2016-05-20

Envelope insulation is a relevant technical solution to cut energy consumption and reduce environmental impacts in buildings. Insulation Cork Boards (ICB) are a natural thermal insulation material whose production promotes the recycling of agricultural waste. The aim of this paper is to determine and evaluate the environmental impacts of the production, use, and end-of-life processing of ICB. A "cradle-to-cradle" environmental Life Cycle Assessment (LCA) was performed according to International LCA standards and the European standards on the environmental evaluation of buildings. These results were based on site-specific data and resulted from a consistent methodology, fully described in the paper for each life cycle stage: Cork oak tree growth, ICB production, and end-of-life processing-modeling of the carbon flows ( i.e. , uptakes and emissions), including sensitivity analysis of this procedure; at the production stage-the modeling of energy processes and a sensitivity analysis of the allocation procedures; during building operation-the expected service life of ICB; an analysis concerning the need to consider the thermal diffusivity of ICB in the comparison of the performance of insulation materials. This paper presents the up-to-date "cradle-to-cradle" environmental performance of ICB for the environmental categories and life-cycle stages defined in European standards.

Insulation Cork Boards—Environmental Life Cycle Assessment of an Organic Construction Material

Directory of Open Access Journals (Sweden)

José D. Silvestre

2016-05-01

Full Text Available Envelope insulation is a relevant technical solution to cut energy consumption and reduce environmental impacts in buildings. Insulation Cork Boards (ICB are a natural thermal insulation material whose production promotes the recycling of agricultural waste. The aim of this paper is to determine and evaluate the environmental impacts of the production, use, and end-of-life processing of ICB. A “cradle-to-cradle” environmental Life Cycle Assessment (LCA was performed according to International LCA standards and the European standards on the environmental evaluation of buildings. These results were based on site-specific data and resulted from a consistent methodology, fully described in the paper for each life cycle stage: Cork oak tree growth, ICB production, and end-of-life processing-modeling of the carbon flows (i.e., uptakes and emissions, including sensitivity analysis of this procedure; at the production stage—the modeling of energy processes and a sensitivity analysis of the allocation procedures; during building operation—the expected service life of ICB; an analysis concerning the need to consider the thermal diffusivity of ICB in the comparison of the performance of insulation materials. This paper presents the up-to-date “cradle-to-cradle” environmental performance of ICB for the environmental categories and life-cycle stages defined in European standards.

Dynamic thermal performance of alveolar brick construction system

International Nuclear Information System (INIS)

Gracia, A. de; Castell, A.; Medrano, M.; Cabeza, L.F.

2011-01-01

Highlights: → Even though U-value does not measure thermal inertia, it is the commonly used parameter. → The thermal performance analysis of buildings must include the evaluation of transient parameters. → Transient parameters of alveolar brick constructive system show good agreement with its low energy consumption. -- Abstract: Alveolar bricks are being introduced in building sector due to the simplicity of their construction system and to the elimination of the insulation material. Nevertheless, it is not clear if this new system is energetically efficient and which is its thermal behaviour. This paper presents an experimental and theoretical study to evaluate the thermal behaviour of the alveolar brick construction system, compared with a traditional Mediterranean brick system with insulation. The experimental study consists of measuring the thermal performance of four real house-like cubicles. The thermal transmittance in steady-state, also known as U-value, is calculated theoretically and experimentally for each cubicle, presenting the insulated cubicles as the best construction system, with differences around 45% in comparison to the alveolar one. On the other hand, experimental results show significantly smaller differences on the energy consumption between the alveolar and insulated construction systems during summer period (around 13% higher for the alveolar cubicle). These values demonstrate the high thermal efficiency of the alveolar system. In addition, the lack of agreement between the measured energy consumption and the calculated U-values, guides the authors to analyze the thermal inertia of the different building components. Therefore, several transient parameters, extracted from the heat transfer matrix and from experimental data, are also evaluated. It can be concluded that the alveolar brick construction system presents higher thermal inertia than the insulated one, justifying the low measured energy consumption.

Experimental Study on Hygrothermal Deformation of External Thermal Insulation Cladding Systems with Glazed Hollow Bead

Directory of Open Access Journals (Sweden)

Houren Xiong

2016-01-01

Full Text Available This research analyzes the thermal and strain behavior of external thermal insulation cladding systems (ETICS with Glazed Hollow Beads (GHB thermal insulation mortar under hygrothermal cycles weather test in order to measure its durability under extreme weather (i.e., sunlight and rain. Thermometers and strain gauges are placed into different wall layers to gather thermal and strain data and another instrument measures the crack dimensions after every 4 cycles. The results showed that the finishing coat shrank at early stage (elastic deformation and then the finishing coat tends to expand and become damaged at later stage (plastic deformation. The deformation of insulation layer is similar to that of the finishing coat but its variation amplitude is smaller. Deformation of substrate expanded with heat and contracted with cold due to the small temperature variation. The length and width of cracks on the finishing coat grew as the experiment progressed but with a decreasing growth rate and the cracks stopped growing around 70 cycles.

Use of Several Thermal Analysis Techniques to Study the Cracking of a Nitrile Butadiene Rubber (NBR) Insulator on the Booster Separation Motor (BSM) of the Space Shuttle

Science.gov (United States)

Wingard, Charles D.

1999-01-01

Two different vendor rubber formulations have been used to produce the silica-filled NBR insulators for the BSM of each of the two Solid Rocket Boosters (SRBs) on the Space Shuttle. Each cured insulator is bonded to the BSM aluminum aft closure with an epoxy adhesive, and some of the curved areas in the rubber may have significant residual stresses. A number of recently bonded NBR insulators have shown fine surface cracks, and stressed insulator areas may be aging at a faster rate than unstressed areas, thus hastening the surface cracking. Thermal analysis data on both vendor insulators by Dynamic Mechanical Analysis (DMA) through a temperature/frequency sweep from 24 to 74 C have shown a higher flexural storage modulus and Arrhenius activation energy for the stressed area than for the unstressed area. Other thermal analysis techniques are being used to study the insulator surface vs. bulk interior for better understanding this anomaly.

Experimental assessment of improvements in thermal performance from insulating the thermal bridge at the edge of a floor slab

Directory of Open Access Journals (Sweden)

N. Arias Jiménez

2017-06-01

Full Text Available The problematic of the article rises from the need of improving the thermal quality of the built envelope in the wall complex, specifically in the case of reinforced concrete (most used material in high-rise housing in Chile. Considering the use of insulation on the inside face of the wall, interrupts the continuity of the insulating material where the mezzanine slab and the perimeter walls meet, generating a thermal bridge known as mezzanine front. The purpose then, is to know the impact of the mentioned thermal bridge studying its properties through experimental tests on a thermal chamber. Later, the results will be integrated to a case of study that allows establishing the incidence of the bridge in the overall energetic behavior of through the integration of the results into the Thermal Analysis Simulation software (Tas. Finally, it is concluded a low incidence in the inner heat loses, becoming relevant the behavior of the superficial temperatures.

PCM/wood composite to store thermal energy in passive building envelopes

Science.gov (United States)

Barreneche, C.; Vecstaudza, J.; Bajare, D.; Fernandez, A. I.

2017-10-01

The development of new materials to store thermal energy in a passive building system is a must to improve the thermal efficiency by thermal-regulating the indoor temperatures. This fact will deal with the reduction of the gap between energy supply and energy demand to achieve thermal comfort in building indoors. The aim of this work was to test properties of novel PCM/wood composite materials developed at Riga Technical University. Impregnation of PCM (phase change material) in wood increases its thermal mass and regulates temperature fluctuations during day and night. The PCM used are paraffin waxes (RT-21 and RT-27 from Rubitherm) and the wood used was black alder, the most common wood in Latvia. The PCM distribution inside wood sample has been studied as well as its thermophysical, mechanical and fire reaction properties. Developed composite materials are promising in the field of energy saving in buildings.

Analytical model of heat transfer in porous insulation around cold pipes

DEFF Research Database (Denmark)

Guldbrandsen, Tom; Karlsson, Per W.; Korsgaard, Vagn

2011-01-01

cloth is wrapped around the cold tube and extended through a slit in the tubular insulation and a slot in the facing to the ambient so that condensed water can evaporate into the air. Some of the moisture in that part of the wicking cloth situated in the slit in the tubular insulation will diffuse......A thermal insulation system is analysed that consists of a cold tube insulated with a porous material faced with a vapour retarding foil.Water vapour will diffuse through the vapour retarding foil and condense on the cold tube. To avoid build-up of water in the insulation a hydrophilic wicking...

Building envelope for New Buildings and Energy Renovation of Existing Buildings. Project results

DEFF Research Database (Denmark)

Rudbeck, Claus Christian; Rose, Jørgen; Esbensen, Peter Kjær

1999-01-01

of heat- and moistureflow is insufficiently documented for large insulation thicknesses. Thermal bridges, for instance, plays a larger role for the overall heat loss in these constructions, and moisture in insulation materials will decrease the overall performance of the construction.Due to these facts...... on the following subjects:Scientific basis for calculation programs, Development of calculationsmethods for heat transfer, Development of new building envelope components, Roofing system based on wooden roof elements, Roofing system with drying properties, Moisture uptake and drying from brick constructions...

Repairing the deteriorated thermal insulation in the serpentine - moderator tank - SLCD assemblies

International Nuclear Information System (INIS)

Gyongyosi, Tiberiu

2004-01-01

Deterioration during operation of the thermal insulation at the upper serpentines in the serpentine assembly in the moderator tank of SLCD (the system of localising the failed fuel) can create problems when one scans the fuel channels in case of failure of one of the ventilated air refrigerator in the rooms of the LAC 10 reactor. Recovering the thermal insulation is absolutely necessary but it is difficult to execute because the loading operation with the granulated layer of diatomaceous filtering agent must be effected directly on the moderator tank after some 24 h from the reactor shut down. The paper presents two possible methods of repairing together with the necessary technological facilities

Basalt fiber insulating material with a mineral binding agent for industrial use

Science.gov (United States)

Drozdyuk, T.; Aizenshtadt, A.; Tutygin, A.; Frolova, M.

2016-04-01

The paper considers a possibility of using mining industry waste as a binding agent for heat insulating material on the basis of basalt fiber. The main objective of the research is to produce a heat-insulating material to be applied in machine building in high-temperature environments. After synthetic binder having been replaced by a mineral one, an environmentally sound thermal insulating material having desirable heat-protecting ability and not failing when exposed to high temperatures was obtained.

Thermal simulation of different construction types in six climatic regions on heating and cooling loads

CSIR Research Space (South Africa)

Kumirai, T

2012-10-01

Full Text Available reduces its heating and cooling loads the most. 3. Applying both roof and ceiling insulation should always be avoided. 4. Building insulation is an effective intervention in all climatic regions. 5. Slightly increasing the thermal mass of a wall... were designed to evaluate the following: ? Case A ? base case ? Case B ? insulated walls ? Case C ? insulated walls and insulated ceiling ? Case D ? insulated walls, insulated ceiling and roof ? Case E ? increased thermal mass wall and insulated...

Mechanisms of thermally induced threshold voltage instability in GaN-based heterojunction transistors

Energy Technology Data Exchange (ETDEWEB)

Yang, Shu; Liu, Shenghou; Liu, Cheng; Lu, Yunyou; Chen, Kevin J., E-mail: eekjchen@ust.hk [Department of Electronic and Computer Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon (Hong Kong)

2014-12-01

In this work, we attempt to reveal the underlying mechanisms of divergent V{sub TH}-thermal-stabilities in III-nitride metal-insulator-semiconductor high-electron-mobility transistor (MIS-HEMT) and MOS-Channel-HEMT (MOSC-HEMT). In marked contrast to MOSC-HEMT featuring temperature-independent V{sub TH}, MIS-HEMT with the same high-quality gate-dielectric/III-nitride interface and similar interface trap distribution exhibits manifest thermally induced V{sub TH} shift. The temperature-dependent V{sub TH} of MIS-HEMT is attributed to the polarized III-nitride barrier layer, which spatially separates the critical gate-dielectric/III-nitride interface from the channel and allows “deeper” interface trap levels emerging above the Fermi level at pinch-off. This model is further experimentally validated by distinct V{sub G}-driven Fermi level movements at the critical interfaces in MIS-HEMT and MOSC-HEMT. The mechanisms of polarized III-nitride barrier layer in influencing V{sub TH}-thermal-stability provide guidelines for the optimization of insulated-gate III-nitride power switching devices.

Electromagnetic and thermal analysis of electromagnet for SMART control element drive mechanism

International Nuclear Information System (INIS)

Huh, H.; Kim, J. H.; Park, J. S.; Kim, Y. W.; Kim, J. I.

1999-01-01

A numerical electromagnetic and thermal analysis was performed for the electromagnet which is installed in the control element drive mechanism(CEDM) of the integral reactor SMART. A model for the electromagnetic analysis of the electromagnet was developed and theoretical bases for the model were established. Design parameters related to thrust force were identified, and the optimum design point was determined by analyzing the trend of the magnetic saturation with finite element method. Also It is important that the temperature of the electomagnet windings be maintained within the allowable limit of the insulation, since the electromagnet of CEDM is always supplied with current during the reactor operation. So the thermal analysis of the winding insulation which is composed of polyimide and air were performed by finite element method. The electromagnetic and thermal properties obtained here will be used as input for the optimization analysis of the electromagnet

Analysis on exergy consumption patterns for space heating in Slovenian buildings

International Nuclear Information System (INIS)

Dovjak, Mateja; Shukuya, Masanori; Olesen, Bjarne W.; Krainer, Ales

2010-01-01

Problem of high energy use for heating in Slovenian buildings is analyzed with exergy and energy analysis. Results of both are compared and discussed. Three cases of exterior building walls are located in three climatic zones in winter conditions. Results of energy analyses show that the highest heating energy demand appears in the case with less thermal insulation, especially in colder climate. If the comparison is made only on the energy supply and exergy supply, the results of exergy analysis are the same as those of energy analysis. The main difference appears, if the whole chain of supply and demand is taken into consideration. Exergy calculations enable us to analyze how much exergy is consumed in which part, from boiler to building envelope. They also reveal how much energy is supplied for the purpose of heating. Results show that insulation has much bigger effect than effect of boiler efficiency. However, the most effective solution is to improve building envelope together with boiler efficiency. Better thermal insulation also makes an important contribution to the improvement of thermal comfort conditions. It causes higher surface temperatures resulting in a larger warm radiant exergy emission rate and consequently better thermal comfort.

Thermal damping effect due to a green barrier which includes Arundo donax as bioclimatic element in buildings

Directory of Open Access Journals (Sweden)

P. Rodríguez-Salinas

2017-09-01

Full Text Available Among the main environmental impacts of the operation of residential buildings are those due to greenhouse gases generation as a result of electric consumption of air conditioning systems. The use of vegetation systems in residential buildings represents an alternative to reduce this energy consumption. Green vegetation systems barriers are often used as protection against winds, but recently they are also being used as acoustic dampers. This work explores their use as thermal insulation systems for buildings. Specifically, we report the behavior of an Arundo donax green barrier as a bioclimatic element. The results are analyzed based on indoor and outdoor temperature measurement in prototype buildings, in function of the green barrier presence. Additionally Arundo donax transpiration under extreme environmental conditions was determined.

Safety distance for preventing hot particle ignition of building insulation materials

Directory of Open Access Journals (Sweden)

Jiayun Song

2014-01-01

Full Text Available Trajectories of flying hot particles were predicted in this work, and the temperatures during the movement were also calculated. Once the particle temperature decreased to the critical temperature for a hot particle to ignite building insulation materials, which was predicted by hot-spot ignition theory, the distance particle traveled was determined as the minimum safety distance for preventing the ignition of building insulation materials by hot particles. The results showed that for sphere aluminum particles with the same initial velocities and diameters, the horizontal and vertical distances traveled by particles with higher initial temperatures were higher. Smaller particles traveled farther when other conditions were the same. The critical temperature for an aluminum particle to ignite rigid polyurethane foam increased rapidly with the decrease of particle diameter. The horizontal and vertical safety distances were closely related to the initial temperature, diameter and initial velocity of particles. These results could help update the safety provision of firework display.

Analysis on exergy consumption patterns for space heating in Slovenian buildings

DEFF Research Database (Denmark)

Dovjak, Mateja; Shukuya, Masanori; Olesen, Bjarne W.

2010-01-01

and demand is taken into consideration. Exergy calculations enable us to analyze how much exergy is consumed in which part, from boiler to building envelope. They also reveal how much energy is supplied for the purpose of heating. Results show that insulation has much bigger effect than effect of boiler...... efficiency. However, the most effective solution is to improve building envelope together with boiler efficiency. Better thermal insulation also makes an important contribution to the improvement of thermal comfort conditions. It causes higher surface temperatures resulting in a larger warm radiant exergy...... emission rate and consequently better thermal comfort....

Novel load responsive multilayer insulation with high in-atmosphere and on-orbit thermal performance

Science.gov (United States)

Dye, S.; Kopelove, A.; Mills, G. L.

2012-04-01

Aerospace cryogenic systems require lightweight, high performance thermal insulation to preserve cryopropellants both pre-launch and on-orbit. Current technologies have difficulty meeting all requirements, and advances in insulation would benefit cryogenic upper stage launch vehicles, LH2 fueled aircraft and ground vehicles, and provide capabilities for sub-cooled cryogens for space-borne instruments and orbital fuel depots. This paper reports the further development of load responsive multilayer insulation (LRMLI) that has a lightweight integrated vacuum shell and provides high thermal performance both in-air and on-orbit. LRMLI is being developed by Quest Product Development and Ball Aerospace under NASA contract, with prototypes designed, built, installed and successfully tested. A 3-layer LRMLI blanket (0.63 cm thick, 77 K cold, 295 K hot) had a measured heat leak of 6.6 W/m2 in vacuum and 40.6 W/m2 in air at one atmosphere. In-air LRMLI has an 18× advantage over Spray On Foam Insulation (SOFI) in heat leak per thickness and a 16× advantage over aerogel. On-orbit LRMLI has a 78× lower heat leak than SOFI per thickness and 6× lower heat leak than aerogel. The Phase II development of LRMLI is reported with a modular, flexible, thin vacuum shell and improved on-orbit performance. Structural and thermal analysis and testing results are presented. LRMLI mass and thermal performance is compared to SOFI, aerogel and MLI over SOFI.

Expert Meeting Report: Cladding Attachment Over Exterior Insulation

Energy Technology Data Exchange (ETDEWEB)

Baker, P. [Building Science Corporation, Somerville, MA (United States)

2013-10-01

The addition of insulation to the exterior of buildings is an effective means of increasing the thermal resistance of both wood framed walls as well as mass masonry wall assemblies. The location of the insulation to the exterior of the structure has many direct benefits including better effective R-value from reduced thermal bridging, better condensation resistance, reduced thermal stress on thestructure, as well as other commonly associated improvements such as increased air tightness and improved water management (Hutcheon 1964, Lstiburek 2007). The intent of the meeting was to review the current state of industry knowledge regarding cladding attachment over exterior insulation with a specific focus on: 1. Gravity load resistance, 2. Wind load resistance. The presentations explorethese topics from an engineering design, laboratory testing, field monitoring, as well as practical construction perspective. By bringing various groups together (who have been conduction research or have experience in this area), a more holistic review of the design limits and current code language proposals can be completed and additional gaps identified. The results of which will help informdesign standards and criteria.

Bellanca building, Yellowknife : building envelope retrofit project

Energy Technology Data Exchange (ETDEWEB)

Rajewski, G. [A.D. Williams Engineering Inc., Edmonton, AB (Canada)

2008-07-01

The Bellanca building is a ten-story, commercial office building, located in Yellowknife, Northwest Territories. The owner was concerned about annual fuel consumption, relative to other buildings of similar size. Tenants reported cold drafts and some ice build-up had been reported in the past, on the exterior of the cladding. In addition, some water penetration had occurred during rainfall. This presentation provided background information on the Bellanca building and discussed a building envelope retrofit project. A.D. Williams was hired in late 2006 in order to provide an opinion on the present condition of the building envelope. This presentation described the site investigation and presented an interior and exterior review of the building. It also presented a thermographic survey in order to map thermal anomalies and establish trends. Following acceptance of the report on findings, one of five options was selected for further development. This included removal of existing cladding, exterior gypsum wallboard, fiberglass insulation and application of BASF Walltite CT foam, sheathing, rigid insulation, drainage plane and new cladding. The preliminary design was then presented. This paper also described the tender and award of the contract; construction phase; and substantial completion of the project. tabs, figs.

Passive hygrothermal control of a museum storage building in Vejle

DEFF Research Database (Denmark)

Christensen, Jørgen Erik; Janssen, Hans

2010-01-01

and maintenance costs are currently motivating a paradigm change toward passive control. Passive control, via the thermal and hygric inertia of the building, is gaining a foothold in the museum conservation and building physical community. In this report we document the hygrothermal performance optimisation...... of a museum storage building, related to an existing storage centre in Vejle (Denmark). The current building design already incorporates passive control concepts: thermal inertia is provided by the thick walls, the ground floor and its underlying soil volume, while hygric inertia is provided by the thick...... with the thermal inertia of the ground and thus a higher temperature variation; For those reasons, more heavily insulated walls and roofs could be considered. Their effects on the interior climate and dehumidification load are however not that large. For the floor, no insulation should be added, and it could...

Foam nests provide context-dependent thermal insulation to embryos of three leptodactylid frogs.

Science.gov (United States)

Méndez-Narváez, J; Flechas, S V; Amézquita, A

2015-01-01

The choice of adequate breeding habitat and its associated thermoregulatory conditions are thought to be important in the evolution of amphibian reproductive strategies. Among leptodactylid frogs, there is a terrestrial cline in the oviposition sites chosen to build foam nests for eggs. Although several functions have been attributed to foam nests, their role in temperature regulation for embryos is unclear. Here we tested the hypothesis that foam nests buffer embryos from variation in air temperature. We examined the degree of terrestrial nest sites in three species, finding a terrestrial cline of sites in terms of distance from water. We tested whether this nest-insulation effect varied among these species that differ in the degree of terrestrial nest sites and whether translocating nests impacted embryonic mortality. Our results demonstrate a negative effect of translocating aquatic nests to land, inferred from the highest hatching success in natural nests sites. All nests attenuated environmental thermal variation, but more terrestrial nests buffered embryos from a greater range of temperatures than did aquatic ones. Altogether, our data indicate that foam nests insulate embryos from daily temperature fluctuations among leptodactylid frogs with different degrees of terrestrial nests, which may well have contributed to the evolution of this reproductive strategy.

Nuclear reactor pressure vessel with an inner metal coating covered with a high temperature resistant thermal insulator

International Nuclear Information System (INIS)

1974-01-01

The thermal insulator covering the metal coating of a reactor vessel is designed for resisting high temperatures. It comprises one or several porous layers of ceramic fibers or of stacked metal foils, covered with a layer of bricks or ceramic tiles. The latter are fixed in position by fasteners comprising pins fixed to the coating and passing through said porous layers and fasteners (nut or bolts) for individually fixing the bricks to said pins, whereas ceramic plugs mounted on said bricks or tiles provide for the thermal insulation of the pins and of the nuts or bolts; such a thermal insulation can be applied to high-temperature reactors or to fast reactors [fr

Importance of thermal comfort for library building in Kuching, Sarawak

Energy Technology Data Exchange (ETDEWEB)

Ibrahim, S.H.; Baharun, A.; Abdul Mannan, M.D.; Abang Adenan, D.A. [Department of Civil Engineering, Faculty of Engineering, University Malaysia Sarawak (UNIMAS), 94300 Kota Samarahan, Sarawak (Malaysia)

2013-07-01

Malaysian Government takes an initiative to provide library in housing areas to improve the quality of human capital. However, the government has to evaluate every aspect of their provision to ensure the services provided meet the demands of the users, including the aspect of thermal comfort in the building. For this study, a library constructed using Industrialised Building System (IBS) are selected for thermal comfort evaluation. The data were analyzed using Corrected Effective Temperature (CET) index. From the data analysis, it shows that thermal comfort in the library could not be achieved most of the time unless when the mechanical cooling is used. A series of technical design improvements are then recommended to improve the thermal comfort inside the library by incorporating construction details without increasing the cost.

Treating Fibrous Insulation to Reduce Thermal Conductivity

Science.gov (United States)

Zinn, Alfred; Tarkanian, Ryan

2009-01-01

A chemical treatment reduces the convective and radiative contributions to the effective thermal conductivity of porous fibrous thermal-insulation tile. The net effect of the treatment is to coat the surfaces of fibers with a mixture of transition-metal oxides (TMOs) without filling the pores. The TMO coats reduce the cross-sectional areas available for convection while absorbing and scattering thermal radiation in the pores, thereby rendering the tile largely opaque to thermal radiation. The treatment involves a sol-gel process: A solution containing a mixture of transition-metal-oxide-precursor salts plus a gelling agent (e.g., tetraethylorthosilicate) is partially cured, then, before it visibly gels, is used to impregnate the tile. The solution in the tile is gelled, then dried, and then the tile is fired to convert the precursor salts to the desired mixed TMO phases. The amounts of the various TMOs ultimately incorporated into the tile can be tailored via the concentrations of salts in the solution, and the impregnation depth can be tailored via the viscosity of the solution and/or the volume of the solution relative to that of the tile. The amounts of the TMOs determine the absorption and scattering spectra.

Electric cable insulation pyrolysis and ignition resulting from potential hydrogen burn scenarios for nuclear containment buildings

International Nuclear Information System (INIS)

Berlad, A.L.; Jaung, R.; Pratt, W.T.

1982-01-01

Electric cable insulation in nuclear containment buildings may participate in pyrolysis and combustion processes engendered by hydrogen burn phenomena. This paper examines these pyrolysis/ignition processes of those polymeric materials present in the electric cable insulation and their possible relation to hydrogen burn scenarios

Composite bulk Heat Insulation Made of loose Mineral and Organic Aggregate

Directory of Open Access Journals (Sweden)

Namsone Eva

2015-12-01

Full Text Available The task of building energy-efficiency is getting more important. Every house owner wishes to save up exploitation costs of heating, cooling, hot water production, ventilation, etc. and find cost-effective investments. One of the ways to reduce greenhouse gas emissions (GHGE is to minimize the heat transfer through the building by insulating it. Loose heat insulation is a good alternative to traditional board insulation, it is simple in use and cost-effective. Main drawback of this insulation is tendency to compact during exploitation. In the frame of this research composite loose heat insulation is elaborated, consisting on porous mineral foamed glass aggregate and local organic fiber materials (hemp and flaxen shives. Composite bulk insulation is an alternative solution which combines heat insulating properties and mechanical stability.

Thermal Performance Testing of Cryogenic Multilayer Insulation with Silk Net Spacers

International Nuclear Information System (INIS)

Johnson, W L; Frank, D J; Nast, T C; Fesmire, J E

2015-01-01

Early comprehensive testing of cryogenic multilayer insulation focused on the use of silk netting as a spacer material. Silk netting was used for multiple test campaigns that were designed to provide baseline thermal performance estimates for cryogenic insulation systems. As more focus was put on larger systems, the cost of silk netting became a deterrent and most aerospace insulation firms were using Dacron (or polyester) netting spacers by the early 1970s. In the midst of the switch away from silk netting there was no attempt to understand the difference between silk and polyester netting, though it was widely believed that the silk netting provided slightly better performance. Without any better reference for thermal performance data, the silk netting performance correlations continued to be used. In order to attempt to quantify the difference between the silk netting and polyester netting, a brief test program was developed. The silk netting material was obtained from Lockheed Martin and was tested on the Cryostat-100 instrument in three different configurations, 20 layers with both single and double netting and 10 layers with single netting only. The data show agreement within 15 - 30% with the historical silk netting based correlations and show a substantial performance improvement when compared to previous testing performed using polyester netting and aluminum foil/fiberglass paper multilayer insulation. Additionally, the data further reinforce a recently observed trend that the heat flux is not directly proportional to the number of layers installed on a system. (paper)

Analysis of Lightning-induced Impulse Magnetic Fields in the Building with an Insulated Down Conductor

Science.gov (United States)

Du, Patrick Y.; Zhou, Qi-Bin

This paper presents an analysis of lightning-induced magnetic fields in a building. The building of concern is protected by the lightning protection system with an insulated down conductor. In this paper a system model for metallic structure of the building is constructed first using the circuit approach. The circuit model of the insulated down conductor is discussed extensively, and explicit expressions of the circuit parameters are presented. The system model was verified experimentally in the laboratory. The modeling approach is applied to analyze the impulse magnetic fields in a full-scale building during a direct lightning strike. It is found that the impulse magnetic field is significantly high near the down conductor. The field is attenuated if the down conductor is moved to a column in the building. The field can be reduced further if the down conductor is housed in an earthed metal pipe. Recommendations for protecting critical equipment against lightning-induced magnetic fields are also provided in the paper.

Airborne sound insulation descriptors in the Nordic building regulations - Overview special rules and benefits of changing descriptors

DEFF Research Database (Denmark)

Helimäki, Heikki; Rasmussen, Birgit

2010-01-01

All Nordic countries have sound insulation requirements specified in the building regulations or in sound classification schemes, Class C, referred to in the regulations and published as national standards, which all originate from a common Nordic INSTA-B proposal from the 90’s, thus having a lot...... insulation requirements and is related to an equivalent paper about impact sound insulation requirements. The papers also describe the major benefits of reducing the number of special rules and of changing descriptors to those which best support protection of the residents and development of the building....... These national rules are not easy to find, unless all details of standards and other documents are known and studied carefully, and they cause problems since the building industry is not national anymore. This paper gives an overview of special national rules in the Nordic countries regarding airborne sound...

Insulation Characteristics of Sisal Fibre/Epoxy Composites

Directory of Open Access Journals (Sweden)

A. Shalwan

2017-01-01

Full Text Available Using natural fibres in civil engineering is the aim of many industrial and academics sectors to overcome the impact of synthetic fibres on environments. One of the potential applications of natural fibres composites is to be implemented in insulation components. Thermal behaviour of polymer composites based on natural fibres is recent ongoing research. In this article, thermal characteristics of sisal fibre reinforced epoxy composites are evaluated for treated and untreated fibres considering different volume fractions of 0–30%. The results revealed that the increase in the fibre volume fraction increased the insulation performance of the composites for both treated and untreated fibres. More than 200% insulation rate was achieved at the volume fraction of 20% of treated sisal fibres. Untreated fibres showed about 400% insulation rate; however, it is not recommended to use untreated fibres from mechanical point of view. The results indicated that there is potential of using the developed composites for insulation purposes.

Fabrication and characterization of Aerogel-Polydimethyl siloxane (PDMS) Insulation Film

Science.gov (United States)

Noh, Yeoung ah; Song, Sinae; Taik Kim, Hee

2018-03-01

The building has a large impact on the space heating demand and the indoor environment is affected by climate or daylight. Hence, silica aerogel has generally used as a film to reduce the coefficient of the window in the building. Silica aerogel is a suitable material to apply for insulation material with lower thermal conductivity than that of air to save interior energy. However expensive precursor and drying process were the main issue of the silica aerogel synthesis and practical usage. We attempt to fabricate aerogel insulation film for energy saving through the economic process under ambient pressure. Silica aerogel was synthesized from rice husk ash, which was an agricultural waste to be able to recycle. Taguchi design was used to optimize the parameters (amount of rice husk ash, pH, aging time) controlling the surface area of silica aerogel. The silica aerogel is prepared by sol-gel processing through acidic treatment and aging. The silica aerogel was obtained by modification of silica hydrogel surface and dry at ambient pressure. Finally, aerogel film was respectively fabricated by the different content of aerogel in polydimethylsiloxane (PDMS). Silica aerogel obtained 21 – 24nm average particle size was analyzed by SEM and silica aerogel with high surface area (832.26 m2/g), pore size ( 3.30nm ) was characterized by BET. Then silica Aerogel – PDMS insulation film with thermal conductivity (0.002 W/mK) was analyzed by thermal wave system. The study demonstrates an eco-friendly and low-cost route toward silica – PDMS insulation film with low thermal conductivity (0.002 W/mK).

Occupant responses and energy use in buildings with moderately drifting temperatures

DEFF Research Database (Denmark)

Toftum, Jørn; Olesen, Bjarne W.; Kolarik, Jakub

of installed HVAC system capacity was evaluated by dynamic simulation of building energy consumption and indoor environment, taking into account potential effects on occupants of such non-steady thermal environments. Several building HVAC configurations and locations with different outdoor climate conditions...... were simulated. Two different approaches were used in the human subject experiments; a) exposure of human subjects to temperature ramps with fixed clothing insulation and b) with subjects being allowed to adjust their clothing insulation as desired. In the former experiments, subjects’ thermal...

Building America Top Innovations 2013 Profile – Exterior Rigid Insulation Best Practices

Energy Technology Data Exchange (ETDEWEB)

none,

2013-09-01

In this Top Innovation profile, field and lab studies by BSC, PHI, and NorthernSTAR characterize the thermal, air, and vapor resistance properties of rigid foam insulation and describe best practices for their use on walls, roofs, and foundations.

Thermal analysis and design of passive solar buildings

CERN Document Server

Athienitis, AK

2013-01-01

Passive solar design techniques are becoming increasingly important in building design. This design reference book takes the building engineer or physicist step-by-step through the thermal analysis and design of passive solar buildings. In particular it emphasises two important topics: the maximum utilization of available solar energy and thermal storage, and the sizing of an appropriate auxiliary heating/cooling system in conjunction with good thermal control.Thermal Analysis and Design of Passive Solar Buildings is an important contribution towards the optimization of buildings as systems th

CERTIFICATION OF THE RADIATION RESISTANCE OF COIL INSULATION MATERIAL

CERN Document Server

Polinski, J; Bogdan, P

2013-01-01

The goal of the WP 7.2.1 sub-task of the EuCARD program has been to determine the Nb$_{3}$Sn based accelerator magnet coil electrical insulation resistance against irradiation, which will occur in future accelerators. The scope of the certification covers determination of mechanical, electrical and thermal properties changes due to irradiation. The report presents a selection of the insulation material candidates for future accelerator magnets as well as the definition of the radiation certification methodology with respect of radiation type, energy, doses and irradiation conditions. The test methods and results of the electrical and mechanical insulation materials properties degradation due to irradiation are presented. Thermal conductivity and Kapitza resistance at temperature range from 1.5 K to 2.0 K (superfluid helium conditions) are given.

Investigation of the thermal resistance of timber attic spaces with reflective foil and bulk insulation, heat flow up

Energy Technology Data Exchange (ETDEWEB)

Belusko, M.; Bruno, F.; Saman, W. [Institute for Sustainable Systems and Technologies, University of South Australia, Mawson Lakes Boulevard, SA 5095 (Australia)

2011-01-15

An experimental investigation was undertaken in which the thermal resistance for the heat flow through a typical timber framed pitched roofing system was measured under outdoor conditions for heat flow up. The measured thermal resistance of low resistance systems such as an uninsulated attic space and a reflective attic space compared well with published data. However, with higher thermal resistance systems containing bulk insulation within the timber frame, the measured result for a typical installation was as low as 50% of the thermal resistance determined considering two dimensional thermal bridging using the parallel path method. This result was attributed to three dimensional heat flow and insulation installation defects, resulting from the design and construction method used. Translating these results to a typical house with a 200 m{sup 2} floor area, the overall thermal resistance of the roof was at least 23% lower than the overall calculated thermal resistance including two dimensional thermal bridging. When a continuous layer of bulk insulation was applied to the roofing system, the measured values were in agreement with calculated resistances representing a more reliable solution. (author)

Novel Application of Glass Fibers Recovered From Waste Printed Circuit Boards as Sound and Thermal Insulation Material

Science.gov (United States)

Sun, Zhixing; Shen, Zhigang; Ma, Shulin; Zhang, Xiaojing

2013-10-01

The aim of this study is to investigate the feasibility of using glass fibers, a recycled material from waste printed circuit boards (WPCB), as sound absorption and thermal insulation material. Glass fibers were obtained through a fluidized-bed recycling process. Acoustic properties of the recovered glass fibers (RGF) were measured and compared with some commercial sound absorbing materials, such as expanded perlite (EP), expanded vermiculite (EV), and commercial glass fiber. Results show that RGF have good sound absorption ability over the whole tested frequency range (100-6400 Hz). The average sound absorption coefficient of RGF is 0.86, which is prior to those of EP (0.81) and EV (0.73). Noise reduction coefficient analysis indicates that the absorption ability of RGF can meet the requirement of II rating for sound absorbing material according to national standard. The thermal insulation results show that RGF has a fair low thermal conductivity (0.046 W/m K), which is comparable to those of some insulation materials (i.e., EV, EP, and rock wool). Besides, an empirical dependence of thermal conductivity on material temperature was determined for RGF. All the results showed that the reuse of RGF for sound and thermal insulation material provided a promising way for recycling WPCB and obtaining high beneficial products.

Performance of antisolar insulated roof system

Energy Technology Data Exchange (ETDEWEB)

Ahmad, Irshad [Alternative Energy Development Board (AEDB), House No. 1, Main Nazimuddin Road, F-10/4, Islamabad (Pakistan)

2010-01-15

Rooms with concrete slab roofs directly exposed to the sun become unbearably hot during summer and very cold during winter. Huge amounts of energy are required to keep them comfortable. Application of thermal insulation on roofs significantly reduces energy required for heating and cooling. The effectiveness of roof insulations may be further enhanced if a layer of antisolar coating is applied on top of the insulation. The antisolar coating reflects most of the incident sunlight and prevents the roof from heating up. This reduces the daily cycles of thermal expansion and contraction which cause cracks in the roof slabs for the rainwater to leak through. The antisolar coating prolongs the useful life of the building structure as well as the life of the insulation that evaporates with heat. The method of application of the antisolar coating has been specially developed to eliminate thermal bridges formed between the edges of the tiles. This report presents the results of an experiment conducted at the Attock Refinery Limited (ARL) Rawalpindi to assess the performance of the antisolar insulated roof system. Record of the room temperature before and after the installation of the system shows a significant reduction in the indoor temperature. The room occupants, who used to experience a very high thermal stress after 10:30 am in spite of the 1.5-ton air conditioner operating in the room, felt much relieved after the installation. They had to turn back the thermostat of the air conditioner and even had to switch it off occasionally. A detailed thermal analysis of the room shows that cost of an antisolar system is paid back in less than a year in the form of savings of energy required for air-conditioning in summer and for gas heating in winter. In addition, the system prevents the addition of 150 kg per year of green house gases to the atmosphere for each square meter of the area covered by the system. It also provides a quieter environment by reducing the operational

The Modeling and Simulation of Thermal Analysis at Hydro Generator Stator Winding Insulation

Directory of Open Access Journals (Sweden)

Mihaela Raduca

2006-10-01

Full Text Available This paper presents the modelling and simulation of thermal analysis at hydro generator stator winding. The winding stator is supplied at high voltage of 11 kV for high power hydro generator. To present the thermal analysis for stator winding is presented at supply of coil by 11 kV, when coil is heat and thermal transfer in insulation at ambient temperature.

Thermal responses and its relation with the building outdoor conditions; Respuestas termicas y su relacion con la envolvente del edificio

Energy Technology Data Exchange (ETDEWEB)

Marincic, Irene [Universidad de Sonora, Hermosillo, Sonora (Mexico); Isalgue, Antoni [Universidad Politecnica de Cataluna, Barcelona (Spain)

2000-07-01

In order to understand and to control the indoor thermal behavior in buildings, it is necessary to know the origin of the energies coming into and outside the building, identifying the geometric factors and physical properties, that can modify the thermal balance of the system. In this work, we analyze the thermal behavior of a building experimentally, related with its exterior conditions. Specifically, we analyze the thermal response indoors at different distances from the building envelope, which implies different thermal insulation situations. Supported on temperature measurements in a residential building, which is representative of local construction styles (adjacent other buildings), we analyze the thermal response effects depending on the distances between the considered points and the envelope and on the insulation between both. Applying a methodology based on experimental transfer functions of buildings, the thermal behavior in the temporary and frequency domains is evaluated. With this methodology, it is possible to visualize certain phenomena and to obtain thermal parameters that characterize the dynamic aspects of the thermal response. The main scope is to extract information from the building analysis, in order to extrapolate the behavior conclusions to a proper thermal design of similar constructions. From the thermal responses analysis at different spatial localization, we conclude that the distance from the building envelope (and also its properties) has a great influence on thermal inertia effects, which can modify importantly the thermal response. This phenomena has a parallelism with the skin effect of the magnetic fields penetration in conductors. The spatial localization implies a certain thermal mass involved in each case, which controls the penetration of exterior thermal oscillation. [Spanish] Para poder entender y controlar los comportamientos termicos en el interior de los edificios, es necesario conocer el origen de las energias que

THERMAL INSULATION PROPERTIES RESEARCH OF THE COMPOSITE MATERIAL WATER GLASS–GRAPHITE MICROPARTICLES

Directory of Open Access Journals (Sweden)

V. A. Gostev

2014-05-01

Full Text Available Research results for the composite material (CM water glass–graphite microparticles with high thermal stability and thermal insulation properties are given. A composition consisting of graphite (42 % by weight, water glass Na2O(SiO2n (50% by weight and the hardener - sodium silicofluoric Na2SiF6 (8% by weight. Technology of such composition receipt is suggested. Experimental samples of the CM with filler particles (graphite and a few microns in size were obtained. This is confirmed by a study of samples by X-ray diffraction and electron microscopy. The qualitative and quantitative phase analysis of the CM structure is done. Load limit values leading to the destruction of CM are identified. The character of the rupture surface is detected. Numerical values of specific heat and thermal conductivity are defined. Dependence of the specific heat capacity and thermal conductivity on temperature at monotonic heating is obtained experimentally. Studies have confirmed the increased thermal insulation properties of the proposed composition. CM with such characteristics can be recommended as a coating designed to reduce heat losses and resistant to high temperatures. Due to accessibility and low cost of its components the proposed material can be produced on an industrial scale.

Selenide isotope generator for the Galileo Mission: SIG thermal insulation evaluaion tests

International Nuclear Information System (INIS)

1979-06-01

Since the SIG program required the use of very high performance thermal insulation materials in rather severe thermal and environmental conditions, a thorough screening and testing program was performed. Several types of materials were included in the preliminary survey. Most promising were oxide and carbonaceous fibrous insulations, oxide and carbonaceous foamed materials, and multilayer materials with both powder and cloth spacers. The latter were only viable for the vacuum option. In all, over one hundred materials from more than sixty manufacturers were evaluated from literature and manufacturers' data. The list was pared to eighteen candidates in seven basic types, i.e., fibrous microporous SiO 2 , fibrous SiO 2 /Al 2 O 3 , fibrous ZrO 2 , fibrous carbon, foamed SiO 2 , foamed carbon, and multilayer. Test results are presented

Assessment of thermal load reduction due to the application of simple passive techniques in a house office building at the south of Libya

International Nuclear Information System (INIS)

Domanski, Roman; Azzain, Gassem

2006-01-01

The assessment of possible reduction of heating and cooling requirements of 300 m 2 house-office building has been presented in this paper, when simple Thermal Passive Techniques (TPT) have been applied to building's construction in Sebha city at the Libyan south. The known software for dynamic simulation (TRNSYS) has been used as an environment of digital experimentation for this study. A prototype represents the building has been constructed with the help of the available model of single thermal zone of TRNSYS (Type 19). The built-in ASHREA Transfer Function Method within this model has been used to calculate the heat flux through building's materials. Primarily, the thermal load on building's construction without TPTs has been evaluated under weather conditions of a Typical Meteorological Year (TMY) of Sebha city. Then, the building has been equipped with simple TPTs (such as the control of building materials, insulation, shading, infiltration and ventilation with windows resizing). This building was subjected to the same weather conditions and again the thermal load has been evaluated in order to report the percentage of reduction of thermal load. The simulation has been conducted successfully, where good assessment of reduction of annual heating and cooling demands in the building has been obtained. It is proved that, about (46%) of annual heating load and (48%) of annual cooling load can be reduced if suitable simple TPTs were incorporated in buildings.(Author)

Insulating materials from renewable raw materials. 3. upd. ed.; Daemmstoffe aus nachwachsenden Rohstoffen

Energy Technology Data Exchange (ETDEWEB)

Brandhorst, Joerg; Spritzendorfer, Josef; Gildhorn, Kai; Hemp, Markus

2009-07-01

Due to increasing energy prices, obligations to climatic protection and the desire for comfortable, allergy-free living, the thermal insulation is a central question with building and sanitation. Under this aspect, the contribution under consideration describes the very dynamic market of the insulating materials from renewable raw materials and deals with the questions of the users. In particular, the following raw materials are considered in the production of insulating materials: Wood fibre, wood chips, wood wool, sheep wool, flax, hemp, reeds, straw, cellulose.

DC Model Cable under Polarity Inversion and Thermal Gradient: Build-Up of Design-Related Space Charge

Directory of Open Access Journals (Sweden)

Nugroho Adi

2017-07-01

Full Text Available In the field of energy transport, High-Voltage DC (HVDC technologies are booming at present due to the more flexible power converter solutions along with needs to bring electrical energy from distributed production areas to consumption sites and to strengthen large-scale energy networks. These developments go with challenges in qualifying insulating materials embedded in those systems and in the design of insulations relying on stress distribution. Our purpose in this communication is to illustrate how far the field distribution in DC insulation systems can be anticipated based on conductivity data gathered as a function of temperature and electric field. Transient currents and conductivity estimates as a function of temperature and field were recorded on miniaturized HVDC power cables with construction of 1.5 mm thick crosslinked polyethylene (XLPE insulation. Outputs of the conductivity model are compared to measured field distributions using space charge measurements techniques. It is shown that some features of the field distribution on model cables put under thermal gradient can be anticipated based on conductivity data. However, space charge build-up can induce substantial electric field strengthening when materials are not well controlled.

Low conductive support for thermal insulation of a sample holder of a variable temperature scanning tunneling microscope.

Science.gov (United States)

Hanzelka, Pavel; Vonka, Jakub; Musilova, Vera

2013-08-01

We have designed a supporting system to fix a sample holder of a scanning tunneling microscope in an UHV chamber at room temperature. The microscope will operate down to a temperature of 20 K. Low thermal conductance, high mechanical stiffness, and small dimensions are the main features of the supporting system. Three sets of four glass balls placed in vertices of a tetrahedron are used for thermal insulation based on small contact areas between the glass balls. We have analyzed the thermal conductivity of the contacts between the balls mutually and between a ball and a metallic plate while the results have been applied to the entire support. The calculation based on a simple model of the setup has been verified with some experimental measurements. In comparison with other feasible supporting structures, the designed support has the lowest thermal conductance.

Renewable building energy systems and passive human comfort solutions

Energy Technology Data Exchange (ETDEWEB)

Omer, Abdeen Mustafa [17 Juniper Court, Forest Road West, Nottingham NG7 4EU (United Kingdom)

2008-08-15

With environmental protection posing as the number one global problem, man has no choice but to reduce his energy consumption. One way to accomplish this is to resort to passive and low-energy systems to maintain thermal comfort in buildings. The conventional and modern designs of wind towers can successfully be used in hot arid regions to maintain thermal comfort (with or without the use of ceiling fans) during all hours of the cooling season, or a fraction of it. Climatic design is one of the best approaches to reduce the energy cost in buildings. Proper design is the first step of defence against the stress of the climate. Buildings should be designed according to the climate of the site, reducing the need for mechanical heating or cooling. Hence maximum natural energy can be used for creating a pleasant environment inside the built envelope. Technology and industry progress in the last decade diffused electronic and informatics' devices in many human activities, and also in building construction. The utilisation and operating opportunities components, increase the reduction of heat losses by varying the thermal insulation, optimise the lighting distribution with louver screens and operate mechanical ventilation for coolness in indoor spaces. In addition to these parameters the intelligent envelope can act for security control and became an important part of the building domotic revolution. Application of simple passive cooling measure is effective in reducing the cooling load of buildings in hot and humid climates. Fourty-three percent reductions can be achieved using a combination of well-established technologies such as glazing, shading, insulation, and natural ventilation. More advanced passive cooling techniques such as roof pond, dynamic insulation, and evaporative water jacket need to be considered more closely. The building sector is a major consumer of both energy and materials worldwide, and that consumption is increasing. Most industrialised

Numerical investigation on thermal and fluid dynamic behaviors of solar chimney building systems

International Nuclear Information System (INIS)

Manca, O.; Nardini, S.; Romano, P.; Mihailov, E.

2013-01-01

Full text: Buildings as big energy-consuming systems require large amount of energy to operate. Globally, buildings are responsible for approximately 40% of total world annual energy consumption. Sustainable buildings with renewable energy systems are trying to operate independently without consumption of conventional resources. Renewable energy is a significant approach to reduce resource consumption in sustainable building. A solar chimney is essentially divided into two parts, one - the solar air heater (collector) and second - the chimney. Two configurations of solar chimney are usually used: vertical solar chimney with vertical absorber geometry, and roof solar chimney. For vertical solar chimney, vertical glass is used to gain solar heat. Designing a solar chimney includes height, width and depth of cavity, type of glazing, type of absorber, and inclusion of insulation or thermal mass. Besides these system parameters, other factors such as the location, climate, and orientation can also affect its performance. In this paper a numerical investigation on a prototypal solar chimney system integrated in a south facade of a building is presented. The analysis is carried out on a three-dimensional model in air flow and the governing equations are given in terms of k-s turbulence model. Two geometrical configurations are investigated: 1) a channel with vertical parallel walls and 2) a channel with principal walls one vertical and the other inclined. The problem is solved by means of the commercial code Ansys-Fluent and the results are performed for a uniform wall heat flux on the vertical wall is equal to 300 and 600 W/m2. Results are given in terms of wall temperature distributions, air velocity and temperature fields and transversal profiles in order to evaluate the differences between the two base configurations and thermal and fluid dynamic behaviors. Further, the ground effect on thermal performances is examined. key words: mathematical modeling, solar chimney

Thermal analysis of linear pulse motor for SMART control element drive mechanism

International Nuclear Information System (INIS)

Hur, H.; Kim, J. H.; Kim, J. I.; Jang, K. C.; Kang, D. H.

1999-01-01

It is important that the temperature of the motor windings be maintained within the allowable limit of the insulation, since the linear pulse motor of CEDM is always supplied with current during the reactor operation. In this study three motor windings were fabricated with three different diameters of coil wires, and the temperatures inside the windings were measured with different current values. As the insulation of the windings is composed of teflon, glass fiber, and air, it is not an easy task to determine experimentally the thermal properties of the complex insulation. In this study, the thermal properties of the insulation were obtained by comparing the results of finite element thermal analyses and those of experiment. The thermal properties obtained here will be used as input for the optimization analysis of the motor

Absolute measurement of the thermal conductivity of insulating materials at high temperature

International Nuclear Information System (INIS)

Liermann, J.

1975-01-01

A device was developed at the CEA for the absolute measurement of the thermal conductivity of insulators. It can operate in controlled atmospheres (air, CO 2 , Ar, He) and between 100 and 1050 deg C [fr

Thermal Analysis of Low Layer Density Multilayer Insulation Test Results

Science.gov (United States)

Johnson, Wesley L.

2011-01-01

Investigation of the thermal performance of low layer density multilayer insulations is important for designing long-duration space exploration missions involving the storage of cryogenic propellants. Theoretical calculations show an analytical optimal layer density, as widely reported in the literature. However, the appropriate test data by which to evaluate these calculations have been only recently obtained. As part of a recent research project, NASA procured several multilayer insulation test coupons for calorimeter testing. These coupons were configured to allow for the layer density to be varied from 0.5 to 2.6 layer/mm. The coupon testing was completed using the cylindrical Cryostat-l00 apparatus by the Cryogenics Test Laboratory at Kennedy Space Center. The results show the properties of the insulation as a function of layer density for multiple points. Overlaying these new results with data from the literature reveals a minimum layer density; however, the value is higher than predicted. Additionally, the data show that the transition region between high vacuum and no vacuum is dependent on the spacing of the reflective layers. Historically this spacing has not been taken into account as thermal performance was calculated as a function of pressure and temperature only; however the recent testing shows that the data is dependent on the Knudsen number which takes into account pressure, temperature, and layer spacing. These results aid in the understanding of the performance parameters of MLI and help to complete the body of literature on the topic.

Depolarization current relaxation process of insulating dielectrics after corona poling under different charging conditions

Directory of Open Access Journals (Sweden)

J. W. Zhang

2017-10-01

Full Text Available As an insulating dielectric, polyimide is favorable for the application of optoelectronics, electrical insulation system in electric power industry, insulating, and packaging materials in space aircraft, due to its excellent thermal, mechanical and electrical insulating stability. The charge storage profile of such insulating dielectric is utmost important to its application, when it is exposed to electron irradiation, high voltage corona discharge or other treatments. These treatments could induce changes in physical and chemical properties of treated samples. To investigate the charge storage mechanism of the insulating dielectrics after high-voltage corona discharge, the relaxation processes responsible for corona charged polyimide films under different poling conditions were analyzed by the Thermally Stimulated Discharge Currents method (TSDC. In the results of thermal relaxation process, the appearance of various peaks in TSDC spectra provided a deep insight into the molecular status in the dielectric material and reflected stored space charge relaxation process in the insulating polymers after corona discharge treatments. Furthermore, the different space charge distribution status under various poling temperature and different discharge voltage level were also investigated, which could partly reflect the influence of the ambiance condition on the functional dielectrics after corona poling.

Depolarization current relaxation process of insulating dielectrics after corona poling under different charging conditions

Science.gov (United States)

Zhang, J. W.; Zhou, T. C.; Wang, J. X.; Yang, X. F.; Zhu, F.; Tian, L. M.; Liu, R. T.

2017-10-01

As an insulating dielectric, polyimide is favorable for the application of optoelectronics, electrical insulation system in electric power industry, insulating, and packaging materials in space aircraft, due to its excellent thermal, mechanical and electrical insulating stability. The charge storage profile of such insulating dielectric is utmost important to its application, when it is exposed to electron irradiation, high voltage corona discharge or other treatments. These treatments could induce changes in physical and chemical properties of treated samples. To investigate the charge storage mechanism of the insulating dielectrics after high-voltage corona discharge, the relaxation processes responsible for corona charged polyimide films under different poling conditions were analyzed by the Thermally Stimulated Discharge Currents method (TSDC). In the results of thermal relaxation process, the appearance of various peaks in TSDC spectra provided a deep insight into the molecular status in the dielectric material and reflected stored space charge relaxation process in the insulating polymers after corona discharge treatments. Furthermore, the different space charge distribution status under various poling temperature and different discharge voltage level were also investigated, which could partly reflect the influence of the ambiance condition on the functional dielectrics after corona poling.

 Thermal Insulation System Made of Wood and Paper for Use in Residential Construction

Science.gov (United States)

Zoltán Pásztory; Tibor Horváth; Samuel V. Glass; Samuel L. Zelinka

2015-01-01

This article introduces an insulation system that takes advantage of the low thermal conductivity of still air and is made of wood and paper. The insulation, called the Mirrorpanel, is constructed as a panel of closely spaced layers of coated paper and held together in a frame of wood or fiberboard. Panels have been fabricated and tested at the laboratory scale, whole...

Investigation of the sensitivity of MIS-sensor to thermal decomposition products of cables insulation

Science.gov (United States)

Filipchuk, D. V.; Litvinov, A. V.; Etrekova, M. O.; Nozdrya, D. A.

2017-12-01

Sensitivity of the MIS-sensor to products of thermal decomposition of insulation and jacket of the most common types of cables is investigated. It is shown that hydrogen is evolved under heating the insulation to temperatures not exceeding 250 °C. Registration of the evolved hydrogen by the MIS-sensor can be used for detection of fires at an early stage.

Impact sound insulation descriptors in the Nordic building regulations – Overview special rules and benefits of changing descriptors

DEFF Research Database (Denmark)

Hagberg, Klas; Rasmussen, Birgit

2010-01-01

All Nordic countries have sound insulation requirements specified in the building regulations or in sound classification schemes, Class C, referred to in the regulations and published as national standards, which all originate from a common Nordic INSTA-B proposal from the 90’s, thus having a lot...... insulation requirements and is related to an equivalent paper about airborne sound insulation requirements. The papers also describe the major benefits of reducing the number of special rules and of changing descriptors to those which best support protection of the residents and development of the building....... These national rules are not easy to find, unless all details of standards and other documents are known and studied carefully, and they cause problems since the building industry is not national anymore. This paper gives an overview of special national rules in the Nordic countries regarding impact sound...

Saving millions by thermal insulation; Miljoenen besparen door goede isolatie

Energy Technology Data Exchange (ETDEWEB)

Van der Velden, U. [Nederlands Centrum voor Technische Isolatie NCTI, spijkenisse (Netherlands)

2009-07-15

Corrosion under insulation (CUI) can be reduced by the application of a correctly designed, installed and maintained insulation system. In refrigeration plants a heat flow will occur from the warm outside towards the cold inside. Hot air, containing more moisture, will be distributed to the cold components of the installation, such as separators, intermediate coolers, piping and valves, thus not only facilitating CUI, but also seriously compromising the thermal performance of the system. Furthermore, this moisture could condensate or freeze and compromise the integrity of the installation. Insulation in cold systems is built up with closed cell materials, such as elastomeric foam, PIR (polyisocyanurate) or cellular glass. On the outside a vapor barrier (e.g. reinforced aluminium foil) is essential to prevent hot moist air from penetrating the system. For protection against weather influences and/or mechanical damage, the system should be finished with a (non)metal cladding. [Dutch] Corrosie onder isolatie (CUI) kan worden beperkt door toepassing van een correct ontworpen, geinstalleerd en onderhouden isolatiesysteem. Bij koude-isolatiesystemen treedt een warmtestroom van buiten naar binnen op. Warme lucht - die meer vocht bevat - dringt naar installatiecomponenten, zoals afscheiders, tussenkoelers, leidingen en afstuiters, waarbij niet alleen het risico op CUI aanzienlijk toeneemt, maar ook de isolatiewaarde van het systeem gereduceerd wordt. Vocht kan hierbij ook nog condenseren of bevriezen en de integriteit van de hele installatie in gevaar brengen. Koude-isolatiesystemen dienen te worden opgebouwd met gesloten cel-materiaal, zoals elastomeer schuim, PIR (polyisocyanurate) of cellulair glas. Het systeem dient aan de buitenzijde te worden voorzien van een dampremmende laag (van bijvoorbeeld versterkt aluminiumfolie) om binnendringend vocht te blokkeren. In buitencondities moet het systeem worden voorzien van een (metalen of niet-metalen) eindafwerking, die

Thermal Conductivity of Foam Glasses Prepared using High Pressure Sintering

DEFF Research Database (Denmark)

Østergaard, Martin Bonderup; Petersen, Rasmus Rosenlund; König, Jakob

The increasing focus on better building insulation is important to lower energy consumption. Development of new and improved insulation materials can contribute to solving this problem. Foam glass has a good insulating effect due to its large gas volume (porosity >90 %). It can be produced with o...... the thermal conductivity varies with gas composition. This allows us to determine the contribution of the gas and solid phase to the total thermal conductivity of a foam glass....

Transient thermal sensation and comfort resulting from adjustment of clothing insulation

DEFF Research Database (Denmark)

Goto, Tomonobu; Toftum, Jørn; Fanger, Povl Ole

2003-01-01

This study investigated the transient effects on human thermal responses of clothing adjustments. Two different levels of activity were tested, and the temperature was set to result in a warm or cool thermal sensation at each activity level. The subjects (12 females and 12 males) wore identical...... uniforms and were asked to take off or don a part of the uniform after they had adapted to the experimental conditions for more than 20 minutes. The results showed that the thermal sensation votes responded immediately to the adjustment of clothing insulation and reached a new steady-state level within 5...

Thermal spin current generation and spin transport in Pt/magnetic-insulator/Py heterostructures

Science.gov (United States)

Chen, Ching-Tzu; Safranski, Christopher; Krivorotov, Ilya; Sun, Jonathan

Magnetic insulators can transmit spin current via magnon propagation while blocking charge current. Furthermore, under Joule heating, magnon flow as a result of the spin Seeback effect can generate additional spin current. Incorporating magnetic insulators in a spin-orbit torque magnetoresistive memory device can potentially yield high switching efficiencies. Here we report the DC magneto-transport studies of these two effects in Pt/magnetic-insulator/Py heterostructures, using ferrimagnetic CoFexOy (CFO) and antiferromagnet NiO as the model magnetic insulators. We observe the presence and absence of the inverse spin-Hall signals from the thermal spin current in Pt/CFO/Py and Pt/NiO/Py structures. These results are consistent with our spin-torque FMR linewidths in comparison. We will also report investigations into the magnetic field-angle dependence of these observations.

Use of Several Thermal Analysis Techniques to Study the Cracking of an Nitrile Butadiene Rubber (NBR) Insulator on the Booster Separation Motor (BSM) of the Space Shuttle

Science.gov (United States)

Wingard, Charles D.; Whitaker, Ann F. (Technical Monitor)

2000-01-01

Two different vendor rubber formulations have been used to produce the silica-filled NBR insulators for the BSM used on both of the Solid Rocket Boosters (SRBs) of the Space Shuttle. A number of lots of the BSM insulator in 1998-99 exhibited surface cracks and/or crazing. Each insulator is bonded to the BSM aluminum aft closure with an epoxy adhesive. Induced insulator stresses from adhesive cure are likely greatest where the insulator/adhesive contour is the greatest, thus showing increased insulator surface cracking in this area. Thermal analysis testing by Dynamic Mechanical Analyzer (DMA) and Thermomechanical Analysis (TMA) was performed on one each of the two vendor BSM insulators previously bonded that exhibited the surface cracking. The TMA data from the film/fiber technique yielded the most meaningful results, with thin insulator surface samples containing cracks having roughly the same modulus (stiffness) as thin insulator bulk samples just underneath.

Using passive cooling strategies to improve thermal performance and reduce energy consumption of residential buildings in U.A.E. buildings

Directory of Open Access Journals (Sweden)

Hanan M. Taleb

2014-06-01

Full Text Available Passive design responds to local climate and site conditions in order to maximise the comfort and health of building users while minimising energy use. The key to designing a passive building is to take best advantage of the local climate. Passive cooling refers to any technologies or design features adopted to reduce the temperature of buildings without the need for power consumption. Consequently, the aim of this study is to test the usefulness of applying selected passive cooling strategies to improve thermal performance and to reduce energy consumption of residential buildings in hot arid climate settings, namely Dubai, United Arab Emirates. One case building was selected and eight passive cooling strategies were applied. Energy simulation software – namely IES – was used to assess the performance of the building. Solar shading performance was also assessed using Sun Cast Analysis, as a part of the IES software. Energy reduction was achieved due to both the harnessing of natural ventilation and the minimising of heat gain in line with applying good shading devices alongside the use of double glazing. Additionally, green roofing proved its potential by acting as an effective roof insulation. The study revealed several significant findings including that the total annual energy consumption of a residential building in Dubai may be reduced by up to 23.6% when a building uses passive cooling strategies.

Thermodynamic analyses and assessments of various thermal energy storage systems for buildings

International Nuclear Information System (INIS)

Caliskan, Hakan; Dincer, Ibrahim; Hepbasli, Arif

2012-01-01

Highlights: ► Proposing a novel latent (PCM), thermochemical and sensible (aquifer) TES combination for building heating. ► Performing comprehensive environmental, energy, exergy and sustainability analyses. ► Investigating the effect of varying dead state temperatures on the TESs. - Abstract: In this study, energetic, exergetic, environmental and sustainability analyses and their assessments are carried out for latent, thermochemical and sensible thermal energy storage (TES) systems for phase change material (PCM) supported building applications under varying environment (surrounding) temperatures. The present system consists of a floor heating system, System-I, System-II and System-III. The floor heating system stays at the building floor supported with a floor heating unit and pump. The System-I includes a latent TES system and a fan. The latent TES system is comprised of a PCM supported building envelope, in which from outside to inside; glass, transparent insulation material, PCM, air channel and insulation material are placed, respectively. Furthermore, System-II mainly has a solar-thermochemical TES while there are an aquifer TES and a heat pump in System-III. Among the TESs, the hot and cold wells of the aquifer TES have maximum exergetic efficiency values of 88.782% and 69.607% at 8 °C dead state temperature, respectively. According to the energy efficiency aspects of TESs, the discharging processes of the latent TES and the hot well of the aquifer TES possess the minimum and maximum values of 5.782% and 94.118% at 8 °C dead state temperature, respectively. Also, the fan used with the latent TES is the most environmentally-benign system component among the devices. Furthermore, the most sustainable TES is found for the aquifer TES while the worst sustainable system is the latent TES.

Preparation, Mechanical and Thermal Properties of Cement Board with Expanded Perlite Based Composite Phase Change Material for Improving Buildings Thermal Behavior

Directory of Open Access Journals (Sweden)

Rongda Ye

2015-11-01

Full Text Available Here we demonstrate the mechanical properties, thermal conductivity, and thermal energy storage performance of construction elements made of cement and form-stable PCM-Rubitherm® RT 28 HC (RT28/expanded perlite (EP composite phase change materials (PCMs. The composite PCMs were prepared by adsorbing RT28 into the pores of EP, in which the mass fraction of RT28 should be limited to be no more than 40 wt %. The adsorbed RT28 is observed to be uniformly confined into the pores of EP. The phase change temperatures of the RT28/EP composite PCMs are very close to that of the pure RT28. The apparent density and compression strength of the composite cubes increase linearly with the mass fraction of RT28. Compared with the thermal conductivity of the boards composed of cement and EP, the thermal conductivities of the composite boards containing RT28 increase by 15%–35% with the mass fraction increasing of RT28. The cubic test rooms that consist of six boards were built to evaluate the thermal energy storage performance, it is found that the maximum temperature different between the outside surface of the top board with the indoor temperature using the composite boards is 13.3 °C higher than that of the boards containing no RT28. The thermal mass increase of the built environment due to the application of composite boards can contribute to improving the indoor thermal comfort and reducing the energy consumption in the buildings.

Preparation, Mechanical and Thermal Properties of Cement Board with Expanded Perlite Based Composite Phase Change Material for Improving Buildings Thermal Behavior.

Science.gov (United States)

Ye, Rongda; Fang, Xiaoming; Zhang, Zhengguo; Gao, Xuenong

2015-11-13

Here we demonstrate the mechanical properties, thermal conductivity, and thermal energy storage performance of construction elements made of cement and form-stable PCM-Rubitherm® RT 28 HC (RT28)/expanded perlite (EP) composite phase change materials (PCMs). The composite PCMs were prepared by adsorbing RT28 into the pores of EP, in which the mass fraction of RT28 should be limited to be no more than 40 wt %. The adsorbed RT28 is observed to be uniformly confined into the pores of EP. The phase change temperatures of the RT28/EP composite PCMs are very close to that of the pure RT28. The apparent density and compression strength of the composite cubes increase linearly with the mass fraction of RT28. Compared with the thermal conductivity of the boards composed of cement and EP, the thermal conductivities of the composite boards containing RT28 increase by 15%-35% with the mass fraction increasing of RT28. The cubic test rooms that consist of six boards were built to evaluate the thermal energy storage performance, it is found that the maximum temperature different between the outside surface of the top board with the indoor temperature using the composite boards is 13.3 °C higher than that of the boards containing no RT28. The thermal mass increase of the built environment due to the application of composite boards can contribute to improving the indoor thermal comfort and reducing the energy consumption in the buildings.

[Preventive effects of sound insulation windows on the indoor noise levels in a street residential building in Beijing].

Science.gov (United States)

Guo, Bin; Huang, Jing; Guo, Xin-biao

2015-06-18

To evaluate the preventive effects of sound insulation windows on traffic noise. Indoor noise levels of the residential rooms (on both the North 4th ring road side and the campus side) with closed sound insulation windows were measured using the sound level meter, and comparisons with the simultaneously measured outdoor noise levels were made. In addition, differences of indoor noise levels between rooms with closed sound insulation windows and open sound insulation windows were also compared. The average outdoor noise levels of the North 4th ring road was higher than 70 dB(A), which exceeded the limitation stated in the "Environmental Quality Standard for Noise" (GB 3096-2008) in our country. However, with the sound insulation windows closed, the indoor noise levels reduced significantly to the level under 35 dB(A) (Pwindows had significant influence on the indoor noise levels (Pwindow, when the sound insulation windows were closed, the indoor noise levels reduced 18.8 dB(A) and 8.3 dB(A) in residential rooms facing North 4th ring road side and campus side, respectively. The results indicated that installation of insulation windows had significant noise reduction effects on street residential buildings especially on the rooms facing major traffic roads. Installation of the sound insulation windows has significant preventive effects on indoor noise in the street residential building.

EVALUATION OF THERMAL INSULATION FOR THREE DIFFERENT MATERIALS USED IN CONSTRUCTION AND COMPLETION OF EXTERNAL WALLS

Directory of Open Access Journals (Sweden)

Marcio Carlos Navroski

2010-05-01

Full Text Available Summers increasingly hot are bringing large thermal problems within homes and businesses, leading to increased demand for installation of air conditioners and the consequent high energy consumption. Constructions with thermal insulation on its external walls thatcould reduce energy use or even supply the use of such equipment. Due to these factors the present study was to evaluate the insulation in three boxes built with different materials, one made of wooden boards with plain walls, and two built with plywood, wall insulation andinterior walls filled with rice husk and Styrofoam®. The boxes were built after placed in drying oven at 40 °C, then noted the temperature inside the same interval every five minutes using a digital thermometer. The box with inner Styrofoam® showed the lowest variation among the three evaluated, followed by the box of rice husk. These two materials also showed good thermal initial, unlike the box built only with wood, which showed a large interiorheating, lay in a drying oven.

Minimization of thermal insulation thickness taking into account condensation on external walls

OpenAIRE

Nurettin Yamankaradeniz

2015-01-01

Condensation occurs in the inner layers of construction materials at whatever point the partial pressure of water vapor diffuses and reaches its saturation pressure. Condensation, also called sweating, damages materials, reduces thermal resistance, and by increasing the total heat transfer coefficient, results in unwanted events such as increased heat loss. This study applied minimization of thermal insulation thickness with consideration given to condensation in the external walls. The calcu...

Expert Meeting Report: Cladding Attachment Over Exterior Insulation (BSC Report)

Energy Technology Data Exchange (ETDEWEB)

None

2013-10-01

The addition of insulation to the exterior of buildings is an effective means of increasing the thermal resistance of both wood framed walls as well as mass masonry wall assemblies. The location of the insulation to the exterior of the structure has many direct benefits including better effective R-value from reduced thermal bridging, better condensation resistance, reduced thermal stress on the structure, as well as other commonly associated improvements such as increased air tightness and improved water management (Hutcheon 1964, Lstiburek 2007). The intent of the meeting was to review the current state of industry knowledge regarding cladding attachment over exterior insulation with a specific focus on: 1. Gravity load resistance, 2. Wind load resistance. The presentations explore these topics from an engineering design, laboratory testing, field monitoring, as well as practical construction perspective. By bringing various groups together (who have been conduction research or have experience in this area), a more holistic review of the design limits and current code language proposals can be completed and additional gaps identified. The results of which will help inform design standards and criteria.

Ecological and Economic Use of Energy by Optimization of Building Construction

International Nuclear Information System (INIS)

Jahrmann, H. J.

1998-01-01

A major part of energy used in daily life is consumed by heating buildings during cold weather periods and for cooling buildings at warmer times. Another major use of energy takes place during production of building materials, construction of the building itself and the depletion and disposal of this building at the end of its lifecycle. Therefore it seems apparent, that effective conservation and saving of energy is a very comprehensive and total approach. The topic is not solely energy saving, it rather is the most effective use of economical and ecological resources. To be energy conscious we have to give closer look to all phases in the existence of a building, and not only of the building. The human being as well must be thoroughly considered in his surrounding, all aspects of his housing suspected for the waste and potential of energy use. So human itself, with his well being in the house, is a major source of energy use. Even the humans health and sickness with its need for cure will cause significant energy input. In the first phase of energy saving programs two aspects should be focused: 1. Primary energy need of construction materials: Primary energy need is the amount of energy used to produce a construction material; from its base origin up to assembling in the housing. Complete ecological balances already exist for a number of materials. Significant difference between materials is observed. The potential for energy saving is impressive. At least 10-30% total energy conservation during the lifecycle of a building appears likely. In many cases a strong positive impact on local economy is expected too. 2. Energy saving by improvement of the thermal quality of buildings: Energy conscious construction of buildings shows an enormous potential for saving. Thermal insulation and effective heating and ventilation systems promise energy savings in the amount of 30-70%. Infrared thermal building analysis and software simulations used prior revitalization of

ECONOMIC AND FINANCIAL ANALYSIS OF THE BUILDINGS REHABILITATION SOLUTIONS

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STAN IVAN F.E.

2016-07-01

Full Text Available The paper includes a simplified economical and financial analysis of the buildings rehabilitation solutions, for heating and lighting. The most important economic and financial indicators analyzed and determined are: economic return on investment and payback period of investment in dynamic form, net present value, and internal rate of return economic residual value of the investment on thermal insulation, building maintenance costs, energy costs. In order to reduce the electricity consumption: the methods consisted in replacing inefficient lighting with some efficient energy and for heat consumption: the proposed solution was building rehabilitation (exterior wall insulation, floor insulation board. The analysis consists in determining the economical and financial indicators before and after the building rehabilitation. The 3 rooms apartment is located in Craiova town, (wind zone IV, 2nd floor, orientation is S.

Thermal assault and polyurethane foam-evaluating protective mechanisms

International Nuclear Information System (INIS)

Williamson, C.L.; Iams, Z.L.

2004-01-01

Rigid polyurethane foam utilizes a variety of mechanisms to mitigate the thermal assault of a ''regulatory burn''. Polymer specific heat and foam k-factor are of limited usefulness in predicting payload protection. Properly formulated rigid polyurethane foam provides additional safeguards by employing ablative mechanisms which are effective even when the foam has been crushed or fractured as a result of trauma. The dissociative transitions from polymer to gas and char, and the gas transport of heat from inside the package out into the environment are also thermal mitigators. Additionally, the in-situ production of an intumescent, insulative, carbonaceous char, confers thermal protection even when a package's outer steel skin has been breached. In this test program, 19 liter, ''Five gallon'' steel pails are exposed on one end to the flame of an ''Oil Burner'' as described in the US Federal Aviation Administration (FAA) ''Aircraft Materials Fire Test Handbook''. When burning 2 diesel at a nominal rate of 8.39 kg (18.5 pounds)/hr, the burner generates a high emissivity flame that impinges on the pail face with the thermal intensity of a full scale pool-fire environment. Results of these tests, TGA and MDSC analysis on the subject foams are reported, and their relevance to full size packages and pool fires are discussed

Protection against cold in prehospital care-thermal insulation properties of blankets and rescue bags in different wind conditions.

Science.gov (United States)

Henriksson, Otto; Lundgren, J Peter; Kuklane, Kalev; Holmér, Ingvar; Bjornstig, Ulf

2009-01-01

In a cold, wet, or windy environment, cold exposure can be considerable for an injured or ill person. The subsequent autonomous stress response initially will increase circulatory and respiratory demands, and as body core temperature declines, the patient's condition might deteriorate. Therefore, the application of adequate insulation to reduce cold exposure and prevent body core cooling is an important part of prehospital primary care, but recommendations for what should be used in the field mostly depend on tradition and experience, not on scientific evidence. The objective of this study was to evaluate the thermal insulation properties in different wind conditions of 12 different blankets and rescue bags commonly used by prehospital rescue and ambulance services. The thermal manikin and the selected insulation ensembles were setup inside a climatic chamber in accordance to the modified European Standard for assessing requirements of sleeping bags. Fans were adjusted to provide low (value, Itr (m2 C/Wclo; where C = degrees Celcius, and W = watts), was calculated from ambient air temperature (C), manikin surface temperature (C), and heat flux (W/m2). In the low wind condition, thermal insulation of the evaluated ensembles correlated to thickness of the ensembles, ranging from 2.0 to 6.0 clo (1 clo = 0.155 m2 C/W), except for the reflective metallic foil blankets that had higher values than expected. In moderate and high wind conditions, thermal insulation was best preserved for ensembles that were windproof and resistant to the compressive effect of the wind, with insulation reductions down to about 60-80% of the original insulation capacity, whereas wind permeable and/or lighter materials were reduced down to about 30-50% of original insulation capacity. The evaluated insulation ensembles might all be used for prehospital protection against cold, either as single blankets or in multiple layer combinations, depending on ambient temperatures. However, with extended

A water blown urethane insulation for use in cryogenic environments

Science.gov (United States)

Blevins, Elana; Sharpe, Jon

1995-01-01

Thermal Protection Systems (TPS) of NASA's Space Shuttle External Tank include polyurethane and polyisocyanurate modified polyurethane foam insulations. These insulations, currently foamed with CFC 11 blowing agent, serve to maintain cryogenic propellant quality, maintain the external tank structural temperature limits, and minimize the formation of ice and frost that could potentially damage the ceramic insulation on the space shuttle orbiter. During flight the external tank insulations are exposed to mechanical, thermal and acoustical stresses. TPS must pass cryogenic flexure and substrate adhesion tests at -253 C, aerothermal and radiant heating tests at fluxes up to approximately 14 kilowatts per square meter, and thermal conductivity tests at cryogenic and elevated temperatures. Due to environmental concerns, the polyurethane insulation industry and the External Tank Project are tasked with replacing CFC 11. The flight qualification of foam insulations employing HCFC 141b as a foaming agent is currently in progress; HCFC 141b blown insulations are scheduled for production implementation in 1995. Realizing that the second generation HCFC blowing agents are an interim solution, the evaluation of third generation blowing agents with zero ozone depletion potential is underway. NASA's TPS Materials Research Laboratory is evaluating third generation blowing agents in cryogenic insulations for the External Tank; one option being investigated is the use of water as a foaming agent. A dimensionally stable insulation with low friability, good adhesion to cryogenic substrates, and acceptable thermal conductivity has been developed with low viscosity materials that are easily processed in molding applications. The development criteria, statistical experimental approach, and resulting foam properties will be presented.

Investigation of deterioration mechanism of electrical ceramic insulating materials under high temperature

International Nuclear Information System (INIS)

Mizutani, Yoshinobu; Ito, Tetsuo; Okamoto, Tatsuki; Kumazawa, Ryoji; Aizawa, Rie; Moriyama, Hideshige

2000-01-01

It is thought that ceramic insulator can be applied to electric power equipments that are under high temperature not to be able use organic materials. Our research has suggested components of mica-alumina combined insulation. As the results of and carried out temperature accelerating test, combined insulation life is expected long term over 40 years at over 500-Celsius degrees. However to construct high reliable insulating system, it is clarified deterioration mechanism on combined insulation and evaluates life of that. Therefore we carried out metal behavior test and voltage aging test using mica-sheet and alumina-cloth that are components of combined insulation under high temperature in nitrogen gas atmosphere. It is cleared two metal behavior mechanisms: One is that the opening of insulator are filled up with copper that is oxidized, the other is the metal diffuses in alumina-cloth through surface. And distance of metal behavior is able to be estimated at modulate temperature and in modulate time. It is also cleared that alumina-cloth is deteriorated by metal behavior into alumina-cloth. These results indicate that combined insulation is deteriorated from electrode side by metal behavior and is finally broken down through alumina-cloth. (author)

Fibrous-Ceramic/Aerogel Composite Insulating Tiles

Science.gov (United States)

White, Susan M.; Rasky, Daniel J.

2004-01-01

Fibrous-ceramic/aerogel composite tiles have been invented to afford combinations of thermal-insulation and mechanical properties superior to those attainable by making tiles of fibrous ceramics alone or aerogels alone. These lightweight tiles can be tailored to a variety of applications that range from insulating cryogenic tanks to protecting spacecraft against re-entry heating. The advantages and disadvantages of fibrous ceramics and aerogels can be summarized as follows: Tiles made of ceramic fibers are known for mechanical strength, toughness, and machinability. Fibrous ceramic tiles are highly effective as thermal insulators in a vacuum. However, undesirably, the porosity of these materials makes them permeable by gases, so that in the presence of air or other gases, convection and gas-phase conduction contribute to the effective thermal conductivity of the tiles. Other disadvantages of the porosity and permeability of fibrous ceramic tiles arise because gases (e.g., water vapor or cryogenic gases) can condense in pores. This condensation contributes to weight, and in the case of cryogenic systems, the heat of condensation undesirably adds to the heat flowing to the objects that one seeks to keep cold. Moreover, there is a risk of explosion associated with vaporization of previously condensed gas upon reheating. Aerogels offer low permeability, low density, and low thermal conductivity, but are mechanically fragile. The basic idea of the present invention is to exploit the best features of fibrous ceramic tiles and aerogels. In a composite tile according to the invention, the fibrous ceramic serves as a matrix that mechanically supports the aerogel, while the aerogel serves as a low-conductivity, low-permeability filling that closes what would otherwise be the open pores of the fibrous ceramic. Because the aerogel eliminates or at least suppresses permeation by gas, gas-phase conduction, and convection, the thermal conductivity of such a composite even at

Marginal costs of intensified energy-efficiency measures in residential buildings; Grenzkosten bei forcierten Energie-Effizienzmassnahmen in Wohngebaeuden

Energy Technology Data Exchange (ETDEWEB)

Jakob, M.; Jochem, E. [Eidgenoessische Technische Hochschule (ETH), Centre for Energy Policy and Economics (CEPE), Zuerich (Switzerland); Kristen, K. [Eidgenoessische Technische Hochschule (ETH), Architektur und Baurealisation, Zuerich (Switzerland)

2002-07-01

This detailed report for the Swiss Federal Office of Energy (SFOE) examines the large potential for increasing the energy efficiency of residential buildings in Switzerland. The aims of the research project are described including investigation of costs and marginal costs for thermal insulation and efficiency measures, the updating of technical parameters for cost - efficiency characteristics on an empirical basis, a transparent presentation of cost/benefit ratios for different concepts. Another aim is to obtain a more detailed overview of costs and benefits that could be of use for planners, building owners and technology companies. The methodology used for the collection of data for the study is described. The report also takes a look at the indirect advantages of improving the thermal insulation of buildings and examines the initial economic and technical situation. A detailed review of the costs and benefits is given for the various elements of a building such as walls, floors and windows and a reference development scenario for the period 2000 -2030 is presented. Marginal cost curves for various categories of buildings are presented for thermal insulation and ventilation measures.

Quantification of Improvement in Environmental Quality for Old Residential Buildings Using Life Cycle Assessment

Directory of Open Access Journals (Sweden)

Jozef Mitterpach

2016-12-01

Full Text Available In Slovakia, 35% of buildings are older than 50 years but most newer buildings built before 1990 have greater energy consumption. Some other countries also have similar problems. The growing importance of energy saving in buildings can be, in the case of new and old residential buildings (RB, achieved by lowering thermal energy consumption most often by application of polystyrene insulation on the external walls and roof and the exchange of wood window frames for PVC (polyvinyl chloride windows. The novelty of the article for Slovakia and some other central European countries consists in using the life cycle assessment (LCA method for the objective assessment of the environmental benefits of the selected systems of wall insulation, as well as of energy savings in various time intervals of insulation functionality (up to 20 years. LCA software SimaPro (LE Amersfoort, The Netherlands was used with ReCiPe and IMPACT 2002+ assessment methods to quantify the total environmental impact at selected endpoints and midpoints (IMPACT 2002+ of basic structural materials of an RB and its energy demand—heat consumption (hot water heating, central heating before the application of insulation and thermal energy saving (TES after application of insulation to its external walls, roof, and the exchange of windows. The data we obtained confirmed that the environmental impact of the polystyrene insulation of external walls, roof, and exchange of windows of one residential building (RB in the first year after insulation is higher than the reduction caused by achieving a TES of 39%. When taking a lifespan of 20 years into consideration, the impact over the life cycle of the building materials is reduced by 25% (global warming: −4792 kg CO2 eq; production of carcinogens: −2479 kg C2H3Cl eq; acidification: −12,045 kg SO2 eq; and aquatic eutrophication: −257 kg PO4 P-lim. The verified LCA methodology will be used for comparative analysis of different variants

Colloquium 3: Thermal insulation materials in construction and in high-temperature plants. Lectures; Kolloquium 3: Waermedaemmstoffe im Bauwesen und in Hochtemperaturanlagen. Vortraege