scholarly journals Thermal conductivity of natural materials used for thermal insulation

2017 ◽  
Author(s):  
Pavel Neuberger ◽  
Pavel Kic
Keyword(s):  
Thermal Conductivity ◽  
Thermal Insulation ◽  
Natural Materials ◽  
Materials Used

scholarly journals Recycling of Nonwoven Polyethylene Terephthalate Textile into Thermal and Acoustic Insulation for More Sustainable Buildings

Polymers ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 3090
Author(s):  
David Antolinc ◽  
Kristina Eleršič Filipič
Keyword(s):  
Thermal Conductivity ◽  
Thermal Insulation ◽  
Water Glass ◽  
Fire Behavior ◽  
Acoustic Properties ◽  
Glass Dissolution ◽  
Acoustic Insulation ◽  
Added Water ◽  
Materials Used ◽  
The Impact

The construction and building sector is responsible for a large share of energy and material used during the life cycle of a building. It is therefore crucial to apply a circular economy model within the process wherever possible to minimize the impact on the environment. In this paper, the possibility of producing thermal and acoustic boards from industrial nonwoven waste textile is studied and presented. The nonwoven polyester textile obtained directly from the production line in the form of strips and bales was first shredded into smaller fractions and then in the form of pile compressed with a hot press to form compact thermal insulation boards. The first set of specimens was prepared only from waste polyester nonwoven textile, whereas the second set was treated with sodium silicate in order to check the material’s reaction to fire performance. The experimental work was conducted to define the acoustic properties, reaction to fire behavior and thermal conductivity of the produced specimens. The obtained results show that the thermal conductivity coefficient of specimens without added water glass dissolution is near to the values of conventional materials used as thermal insulation in buildings. The reaction to fire testing proved that the addition of water glass actually propagates the progressive flame over the entire product. It can be concluded that the presented thermal insulation can be used as an adequate and sustainable solution for building construction purposes.

Experimental Study on the Thermal Conductivity of Thermal Insulation Materials Used in Residential Buildings

2014 ◽  
Vol 1025-1026 ◽  
pp. 535-538
Author(s):  
Young Sun Jeong
Keyword(s):  
Thermal Conductivity ◽  
Thermal Insulation ◽  
Building Materials ◽  
Residential Buildings ◽  
Building Envelope ◽  
Expanded Polystyrene ◽  
Exterior Wall ◽  
Insulation Materials ◽  
Design Documents ◽  
Materials Used

The most basic way to keep comfortable indoor environments for a building’s occupants and save energy for space heating and cooling in residential buildings is to insulate the building envelope. Among the building materials to be used, thermal insulation materials primarily influence thermal performance. In particular, the type, thermal conductivity, density, and thickness of heat insulator, are important factors influencing thermal insulation performance. We investigate the design status of residential buildings which were designed in accordance with the building code of Korea and selected the type of thermal insulation materials applied to the walls of buildings. The present study aims at measuring the thermal conductivity of thermal insulation materials used for building walls of residential buildings. In this study, after collecting the design documents of 129 residential buildings, we investigated the type and thickness of insulation materials on the exterior wall specified in the design documents. As the thermal insulation materials, extruded polystyrene (XPS) board and expanded polystyrene(EPS) board are used the most widely in Korea when designing residential buildings. The thickness of thermal insulation materials applied to the exterior wall was 70mm, most frequently applied to the design. We measured the thermal conductivity and the density of XPS board and EPS board. When the density of XPS and EPS was 30~35 kg/㎥, the thermal conductivity of XPS was 0.0292 W/mK and it of EPS was 0.0316 W/mK.

Effect of carbon reinforcements on selected properties of mortar

2020 ◽  
Vol 17 (4) ◽  
pp. 543-551
Author(s):  
Payman Sahbah Ahmed ◽  
Manar Nazar Ahmed ◽  
Samal Osman Saied
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Thermal Insulation ◽  
Carbon Fibers ◽  
Building Materials ◽  
Building Design ◽  
Content Type ◽  
Micro Particles ◽  
Materials Used ◽  
Short Carbon

Purpose The purpose of this research is using materials to improve the thermal insulation, and reducing the cost. A large amount of energy is consumed by masonary due to cooling and heating. Adding material with certain percentages to the building materials is one of the ways to improve the thermal insulation, and these additives should keep as much as possible the mechanical properties of the building materials. Carbon additives are one of commonly used materials to masonry materials. In spite of the many advantages of using carbon fibers and carbon nano tubes (CNTs) to the cementitious materials, they are very expansive and their thermal conductivity is high. Design/methodology/approach In this research charcoal (which is a product of burning process) with very low thermal conductivity and cost in the form of micro particles will be used with mortar and compared with short carbon fibers and multiwall carbon nanotubes (MWCNTs) via thermal conductivity, density and compressive strength tests. This research includes also an effort to build a model of building to evaluate the thermal insulation of the materials used in the practical part. The main building design and performance simulation tool in this research is DesignBuilder. Findings Results showed that adding micro charcoal particles to mortar resulted in improving the thermal insulation and decrease the rate of reduction in the compressive strength compared to other additives, while adding short carbon fibers resulted in improving the thermal insulation and decrease the compressive strength. Adding MWCNT to the mortar had a negative effect on mechanical and physical properties, i.e. compressive strength, density and thermal insulation. Originality/value This paper uses DesignBuilder software to design a model of building made from the materials used in the practical part to predict and evaluate the thermal insulation.

scholarly journals Evaluation of thermal properties of insulation systems in pitched roofs

2019 ◽  
Vol 91 ◽  
pp. 02047 ◽  
Author(s):  
Alexey Zhukov ◽  
Armen Ter-Zakaryan ◽  
Ekaterina Bobrova ◽  
Igor Bessonov ◽  
Andrey Medvedev ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Thermal Properties ◽  
Water Vapor ◽  
Thermal Resistance ◽  
Heat Loss ◽  
Thermal Insulation ◽  
Insulating Layer ◽  
Insulation Systems ◽  
Materials Used ◽  
Supporting Structures

The article outlines the basic requirements for pitched roof insulation systems. The analysis of the properties of thermal insulation materials used in insulation systems was conducted. It is substantiated that the thermal resistance of such structures on the surface of the roof is formed taking into account the thermal conductivity of thermal insulation, thermal conductivity of wooden rafters and heat loss through the leakiness of joints and mounting devices. An assessment was made of the effect of loads of various types on the heat-insulating layer, namely: the effect of the air flow in the ventilated gap; the movement of the vapor-air mixture in the material; condensation of water vapor and penetration of drip liquid; exfiltration of air at the joints of the plates and on the surfaces of contact with the supporting structures. The expediency of using products on the basis of unstitched polyethylene foam in the construction of pitched roofs with a wooden roof system, taking into account the advantages and features of this material, as well as taking into account the possibility of creating a seamless insulating shell, is substantiated.

Development of Thermal Insulation Composite Material from Recycled Polymer and Recycled Glass

2012 ◽  
Vol 487 ◽  
pp. 701-705 ◽  
Author(s):  
Jan Pěnčík ◽  
Libor Matějka ◽  
Alena Kalužová ◽  
Libor Matějka ◽  
Darina Dostálová ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Composite Material ◽  
Thermal Insulation ◽  
Static Load ◽  
Sustainable Construction ◽  
Mechanical Resistance ◽  
Recycled Glass ◽  
Coefficient Of Thermal Conductivity ◽  
Structural Details ◽  
Materials Used

With the sustainable construction the emphasis is placed on saving energy, reducing of consumption of natural resources, extending the life cycle of recycling, etc. One of the important groups of waste materials that can be reused are waste polymers. These materials are used in the design of thermal insulation composite material. The crucial property of materials used for thermal insulation is the coefficient of thermal conductivity. Thermal conductivity coefficients of waste polymers however do not meet the requirements. For this reason, waste polymers are within the development of thermal insulation composite material combined with filler with a low coefficient of thermal conductivity. In developing of this composite material the developers combine a method of theoretically optimized software design of blends with their production and experimental verification. Possibility of application of thermal insulation composite material can be seen especially in the structural details, in which it is necessary to eliminate the thermal bridges, but also details where the requirements are applied to the mechanical resistance and static load bearing capacity.

scholarly journals STUDIES ON THE THERMAL CONDUCTIVITY OF COMPOSITE MATERIALS BASED ON LOCAL RENEWABLE RESOURCES / KOMPOZICINIŲ TERMOIZOLIACINIŲ MEDŽIAGŲ IŠ VIETINIŲ ATSINAUJINANČIŲ IŠTEKLIŲ ŠILUMOS LAIDUMO TYRIMAI

2011 ◽  
Vol 3 (5) ◽  
pp. 83-88
Author(s):  
Sigitas Vėjelis ◽  
Saulius Vaitkus ◽  
Giedrius Balčiūnas
Keyword(s):  
Thermal Conductivity ◽  
Composite Materials ◽  
Thermal Insulation ◽  
Renewable Resources ◽  
Environmentally Friendly ◽  
Herbaceous Plants ◽  
Mass Ratio ◽  
Crop Straw ◽  
Reed Straw ◽  
Materials Used

Thermal insulation materials produced from local renewable resources are increasingly used for two reasons – they are environmentally friendly and their manufacture requires less amount of energy. The most renewable resources include a wide variety of crop straw – barley, rye, wheat, triticale, etc. the thermal conductivity of which depends on their orientation to the product and structure of the same straw. For specimen composition, the straw stems of bulrush, reeds, bent and triticales were used, producing composites with the mass ratio of 1:1. The paper analyses the results of thermal conductivity tests on different stem composites of herbaceous plants. Thermal conductivity was investigated considering composition specimens such as bulrush-reeds, bulrush-bent, bulrush-straw, reed-straw, reed-bent. The use of composites in all cases reduced thermal conductivity compared with the thermal conductivity of materials used alone. The greatest reduction in thermal conductivity compared with the thermal conductivity of the single straws of herbaceous plants has been observed in bulrush-straw composites. Santrauka Termoizoliacinės medžiagos iš vietinių atsinaujinančių išteklių vis plačiau naudojamos dėl dviejų priežasčių – jos yra ekologiškos ir jų gamybai reikalingi maži energijos kiekiai. Iš atsinaujinančių išteklių labiausiai paplitę įvairių kultūrinių augalų šiaudai: miežių, rugių, kviečių, kvietrugių ir kt. Šių medžiagų šilumos laidumas labiausiai priklauso nuo jų orientacijos gaminyje ir pačių stiebelių struktūros. Bandiniams komponuoti buvo naudojama švendrų, nendrių, smilgų ir kvietrugių šiaudų stiebai, iš kurių pagal masės santykį 1:1 buvo komponuojami kompozitai. Atlikta kompozitų, sudarytų iš skirtingų žolinių augalų stiebelių, šilumos laidumo tyrimai. Tirti tokių sudėčių bandinių šilumos laidumai: švendrai + nendrės, švendrai + smilgos, švendrai + šiaudai, nendrės + šiaudai, nendrės + smilgos. Naudojant kompozitus visais atvejais sumažintas šilumos laidumas lyginant su šilumos laidumu, kai naudotos pavienės medžiagos: didžiausias šilumos laidumo sumažėjimas, lyginant su pavienių augalų stiebų šilumos laidumu, gautas švendrų ir šiaudų kompozite.

scholarly journals Fique as a Sustainable Material and Thermal Insulation for Buildings: Study of Its Decomposition and Thermal Conductivity

2021 ◽  
Vol 13 (13) ◽  
pp. 7484
Author(s):  
Gabriel Fernando García Sánchez ◽  
Rolando Enrique Guzmán López ◽  
Roberto Alonso Gonzalez-Lezcano
Keyword(s):  
Thermal Conductivity ◽  
Thermal Decomposition ◽  
Thermal Insulation ◽  
Model Fitting ◽  
Good Alternative ◽  
Negative Effects ◽  
Thermal Insulator ◽  
Fitting Method ◽  
Thermogravimetric Data ◽  
Reduce Energy Consumption

Buildings consume a large amount of energy during all stages of their life cycle. One of the most efficient ways to reduce their consumption is to use thermal insulation materials; however, these generally have negative effects on the environment and human health. Bio-insulations are presented as a good alternative solution to this problem, thus motivating the study of the properties of natural or recycled materials that could reduce energy consumption in buildings. Fique is a very important crop in Colombia. In order to contribute to our knowledge of the properties of its fibers as a thermal insulator, the measurement of its thermal conductivity is reported herein, employing equipment designed according to the ASTM C 177 standard and a kinetic study of its thermal decomposition from thermogravimetric data through the Coats–Redfern model-fitting method.

scholarly journals Optimum Thickness of Thermal Insulation with Both Economic and Ecological Costs of Heating and Cooling

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3835
Author(s):  
Robert Dylewski ◽  
Janusz Adamczyk
Keyword(s):  
Thermal Insulation ◽  
Construction Materials ◽  
Optimum Thickness ◽  
Degree Days ◽  
Transfer Coefficients ◽  
Cooling Period ◽  
Heating And Cooling ◽  
Optimum Heat ◽  
Materials Used ◽  
Building Walls

The energy efficiency of the construction sector should be determined by the cleanliness of the environment and, thus, the health of society. The scientific aim of this article was to develop a methodology for determining the optimum thickness of thermal insulation, taking into account both economic and ecological aspects and considering both heating and cooling costs. The method takes into account the number of degree days of the heating period, as well as the number of degree days of the cooling period. Variants in terms of different types of thermal insulation, various types of construction materials for building walls, climatic zones and heat sources, were taken into consideration. In order to find the optimum thicknesses of thermal insulation, both in economic and ecological terms, a metacriterion was used. The optimum thicknesses of thermal insulation with the use of the metacriterion were obtained in the range of 0.11–0.55 m. It was observed that the values of the optimum heat transfer coefficients for economic and ecological reasons do not depend on the type of construction materials used for vertical walls. The type of applied heat source is of the greatest importance for the size of the economic and ecological benefits. The proposed mathematical model for determining the optimum thickness of thermal insulation with the use of a metacriterion is a kind of generalization of earlier models from the literature.

scholarly journals Microstructure Dependence of Effective Thermal Conductivity of EB-PVD TBCs

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1838
Author(s):  
Shi-Yi Qiu ◽  
Chen-Wu Wu ◽  
Chen-Guang Huang ◽  
Yue Ma ◽  
Hong-Bo Guo
Keyword(s):  
Thermal Conductivity ◽  
Mechanical Stress ◽  
Effective Thermal Conductivity ◽  
Thermal Insulation ◽  
Inclination Angle ◽  
Physical Vapor Deposition ◽  
Thermal Contact ◽  
Mathematic Model ◽  
Columnar Structure ◽  
Structural Parameter

Microstructure dependence of effective thermal conductivity of the coating was investigated to optimize the thermal insulation of columnar structure electron beam physical vapor deposition (EB-PVD coating), considering constraints by mechanical stress. First, a three-dimensional finite element model of multiple columnar structure was established to involve thermal contact resistance across the interfaces between the adjacent columnar structures. Then, the mathematical formula of each structural parameter was derived to demonstrate the numerical outcome and predict the effective thermal conductivity. After that, the heat conduction characteristics of the columnar structured coating was analyzed to reveal the dependence of the effective thermal conductivity of the thermal barrier coatings (TBCs) on its microstructure characteristics, including the column diameter, the thickness of coating, the ratio of the height of fine column to coarse column and the inclination angle of columns. Finally, the influence of each microstructural parameter on the mechanical stress of the TBCs was studied by a mathematic model, and the optimization of the inclination angle was proposed, considering the thermal insulation and mechanical stress of the coating.

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