Thermal Performance Of Building Materials Research Articles

A comparative LCA of external wall assemblies in context of Iranian market: considering embodied and operational energy through BIM application.

Building envelopes have a critical role in the sustainability of the construction sector. The goals of the current research are assessing the environmental impacts of typical exterior wall assemblies and presenting the best Iranian market option through taking account of both embodied and operational energy. Autodesk Green Building Studio (GBS) is used to determine the operating loads of each wall. Simapro, a life cycle assessment software, is applied for managing data on environmental impacts. The derived results demonstrate that human health is the most severe damage category for all the analyzed walls. Also, the end-of-life stage's environmental impact is insignificant compared to the production and use stages. Reducing carbon emissions has the highest priority, such that replacing 1 m2 of masonry brick wall (the worst option) with prefabricated extruded polystyrene (XPS) drywall (the best option) can result in saving 1257.85 kgCO2eq. The operational phase of the studied walls has a wide range of environmental impacts. Prefabricated Knauf drywall as well as prefabricated XPS drywall consumes less energy for the operating phase mainly due to providing sufficient quantity of isolations that leads to the better total environmental performance. In conclusion, it should be noted that the thermal performance of building materials should be given more attention.

Numerical study of thermal stress of a building material based on clay and date palm fibers

This work aims to present, through a numerical study, the results of the thermal stress that appears within a construction material based on soil stabilized by date palm fibers (PDF) in a dry climate region. These plant fibers constituting an abundant and renewable natural waste have always been favored to develop and improve the thermal performance of building materials, nevertheless the problem of daily temperature variations in these regions leads to cracks that may cause deformations and damage of building walls. The simulation begins with the generation of 3D structures and then homogenization techniques and finite element calculations (FE) are used to estimate the equivalent coefficient of thermal expansion of the composite. This coefficient varies from 5.4.10-6 per °C for pure clay to 5.9.10-6 per °C for a fraction of 30% of date palm fibers, showing that the content of date palm fibers in adobe and clay brick acts on the thermal stress and stability of traditional construction buildings.

Development of affordable hot box calorimeter to determine the U-value of inhomogeneous building material

In recent years, the use of three-dimensional printing to create construction components has advanced quickly; it is possible now to simplify construction, increase speed, and lower cost while using natural resources responsibly. It also allows us to use recycled material to produce building envelopes while increasing design flexibility. However, the thermal performance of building materials must be characterized to achieve the necessary energy efficiency of the building envelopes. This study aims to develop, produce, and calibrate a hot box calorimeter at a reasonable price for thermal testing components building envelope. The heat loss through these components using a hot box can be measured in a lab to get an idea of the thermal performance of the building envelopes. In order to evaluate and analyze the thermal performance of various 3D-printed building brick samples made in the labs, this study explains the design and creation of an inexpensive hot box. The hot box can conduct a conventional thermal experiment, which involves monitoring heat flux, surface temperatures, and air temperatures. The testing process, instrumentation, test conditions, and validation of the new metering box are all covered in the article. The U-value of the brand-new lattice-based 3D printed building blocks was afterward determined using the validated new hot box. It was observed that the U-values values of 1.04 W/m2.K and 0.99 W/m2.K, respectively, for small components utilizing developed hot box and larger lattice panels using commercial equipment, with a maximum variance of 5%. It highlights the dependability of the hot box apparatus, which is also made affordable to operate by using less material for specimen preparation and less energy to maintain the temperature in the hot and cold chambers. Its small size also makes setup and thermal testing of construction materials simple.

An Overview of Thermal Insulation Material for Sustainable Engineering Building Application

Residential buildings help to facilitate the occupants against solar radiation and adverse weather conditions. However, the growing increase in climate change in our environment has resulted in different side effects on human’s health mostly in the northern region of Nigeria and other parts of the world where high radiation from the sun are experience. This has resulted to the key interests of this research on possible thermal insulation materials that can help resist or absorb the solar radiation effects that can cause damage to lives in our community. This literature review of thermal insulation materials aims to proffer a sustainable solution by evaluating the thermal performance of building materials to provide an eco-friendly environment for building occupants. This research also discusses the Application of Thermal Insulation Materials for Developing Roofing sheets. The classification of thermal insulation materials, heat transfer in insulation materials, factors that influence the choice of building materials and thermal conductivity, resistivity, resistance, and conductance. Advantages of building insulation materials on economic, comfort, and environmental were also studied, and the reviewing of previous and incorporating thermal insulation materials with roofs. From the critical review, the application of insulating materials for developing building materials is highly recommended due to the provision of an eco-friending environment with reduced energy consumption during applications of home appliances.

Investigation of thermal performance of newly multilayer wall/roof constructions for low-carbon buildings

Increasing concerns about energy consumption for heating and cooling of buildings have made it necessary to improve the thermal performance of building materials. However, in addition to using materials with high insulation characteristics, an accurate calculation of the capacities of the heating and cooling systems is also an important factor in ensuring high energy efficiency for low-carbon buildings. The devices will not be selected at capacities larger than the capacities that should be on this point and energy wastage will be prevented. To achieve this goal, in this study, investigations are carried out to produce new concrete types with high thermal insulating characteristics. Besides, many new concrete wall and roof samples were produced with different types of aggregates at different volume ratios and their thermophysical characteristics are tested in accordance with ASTM and EN standards. To estimate the thermal performance of produced samples, a periodic solution method, the Complex Finite Fourier Transform technique, is developed by using thermophysical characteristics data of those structures. The results showed that the daily heat gain values were calculated as 65.909 W/m2 for the EPC50 wall and 11.324 W/m2 for the PC40-EPC60 wall with 20 cm thicknesses.

The thermal performances of cement-based materials with different types of microencapsulated phase change materials

Phase change materials (PCMs) have been proposed as a means of building energy conservation due to a large amount of heat being absorbed or released during phase-transition. Recently, the application of the encapsulated PCMs (MPCMs) in cement-based materials is drawing more and more attention for the improvement of the thermal performance of building materials. However, the thermal effect of MPCMs with inorganic silica shells on cement-based materials is rarely focused on. In this study, two types of MPCMs with silica shells respectively at nanometer and micron scale were fabricated, and the effect of MPCMs on the thermal performances of cement-based materials was systematically evaluated. Results showed that the prepared MPCMs increased the enthalpy of phase change but decreased the thermal conductivity of cementitious composites. The heat storage and release characteristics of cement pastes were noted to be strongly dependent on the volume fraction of MPCMs, while small size MPCM exhibited better thermal stability and the effect of MPCMs was strongly correlated with the temperature ramp. The prepared MPCMs significantly improved the thermal inertia of cement pastes and can be used as a thermal storage material in buildings to mitigate the indoor temperature fluctuations. To achieve better building energy conservation, MPCM with higher enthalpy is recommended.

Comparative Analysis of the Use of Thermal Insulation Materials Depending on Climatic Conditions and Comfort Microclimate Supply Systems

The use of thermal insulation materials to reduce the heating and cooling demand of the building in order to provide energy efficiency is the main solution. But there is a wide range of these products on the market and, therefore, the choice and application of these materials is a rather difficult task, since many factors must be taken into account, such as environmental safety, cost, durability, climatic conditions, application technology, etc. Basically, comfort microclimate systems are designed based on normative standards, where the thickness of the thermal insulation material is selected depending on the required heat transfer resistance. These values are calculated taking into account climate conditions, that is the duration of the heating period, as well as taking into account sanitary and hygienic requirements. This article discusses the thermal performance of building materials, and also provides a comparative analysis of the use of thermal insulation materials depending on climatic factors and on the system providing comfort microclimate. Based on the calculations by mathematical modeling and optimization, it is advisable to choose the thickness of the thermal insulation, taking into account the capital and operating costs of the comfort microclimate systems. Comparing the optimization data with the normative one, the energy efficiency of the building increases by 50-70% when applying the optimal thickness of the thermal insulation layer, and when the thermal insulation layer is increased, the thermal performance of the enclosing structures has improved by 30%, which contributes to energy saving.

Study of Condensation Risk in Ecological Blocks with Recycled Wood Aggregate

Abstract Concrete is a building material with a continuous demand in the construction industry due to the convenient price-performance ratio. On the other hand, concrete is not an environmentally friendly material. Thus, in order to obtain a sustainable material, wood waste can be recycled and used as light aggregates in the manufacture of precast ecological building blocks. Block walls must satisfy not only structural criteria but also functional requirements. In addition, thermal contribution is important in reducing energy consumption over the life of the building. The presence of moisture on the exterior walls due to the appearance of condensation will decrease the thermal performance of building materials. This paper analyses the occurring of condensation risk and its location in the outer wall made of wood-concrete blocks by the Glaser method, for different situations of arrangement and composition of the layers.

Thermal performance of building materials based on feather and polystyrene wastes

The development of composites using renewable resources has received attention of scientists over the last decade, with the aim of manufacturing environmentally friendly composites, reducing cost and the dependence on petroleum resources. This experimental study emphasizes the development of new cost-efficient composite based on feather/cotton nonwoven and polystyrene waste. The microstructure and thermal properties have been determined in each FPS material. Vacuum molding method was adopted for fabricating of the biocomposites with two contents of polystyrene matrix (30% and 50%). As a result, the morphological analysis revealed better compatibility and adhesion between the nonwoven and the polystyrene matrix. The manufactured composites showed an insulating character with thermal conductivity coefficient value of 35.95 and 33.85 mW / (m.K) respectively for the composite reinforced with 30 and 50% polystyrene. The origin of the variation of this property is due to densities and the percentage of the polystyrene matrix. The composites developed with polystyrene showed very high performance, combined with sufficient durability to be potential candidates for the development of new sustainable materials for the building sector.

Thermal parameters of roofing slates from Czech Republic

Thermal performance of building materials is an important parameter from the point of view of energy consumption for heating buildings, which is obviously related to environmental protection standards. Thermal parameters of roofing slates were measured for samples from two different formations in the Czech Republic. These were rocks of lower Carboniferous Culm facies of Moravice Formation and Silesian Unit of Flysch Moravian-Silesian Carpathians. Thermal conductivity and thermal effusivity measurements were performed with use of TCi analyser. Thermal parameters were obtained in parallel and perpendicular direction to the bedding in rocks. Thermal conductivity of the Moravian slates in the direction perpendicular to the bedding ranges from 1.43 to 1.79 W m−1 K−1, while for samples from Carpathian region this parameter ranges from 1.99 to 3.15 W m−1 K−1. High values of thermal conductivity correlate to higher quartz content in the rocks. The measured thermal parameters (conductivity, effusivity, diffusivity) are strongly depending on the direction of measurement. Thermal conductivity of analysed rocks increases along with increase in temperature. The increase in thermal conductivity value is more significant in case of Moravian slates. In practice, the obtained results indicate that the traditional building material, such as roofing slates, shows better insulation properties at lower temperatures, while in conditions of strong sunlight the temperature conductivity increases. In case of roofing slates, which tend to be highly anisotropic, the essential information is the direction of thermal parameters measurement. Slates, due to their specific texture, are characterized by a very high thermal anisotropy coefficient.

Improvement Insulating Properties of Ceramic Materials by Incorporating Additives

AbstractThe objective of this study is to improve the thermal performance of masonry bricks produced by the factory Briqueteries du Nord. This industrial plant is located in the north of France. The use of additives in the raw material admixture presents a promising approach for improving the thermal performance of building materials, and consequently to respond of requirements of the thermal regulation. Therefore, three additives are selected as part of an approach supporting sustainable development and waste valorization: flax shives, maize starch, and polystyrene beads. This experimental study is focused on the effect of these additives on the physical, mechanical, and thermal properties of ceramic samples. Different characterization tests were conducted at the laboratory scale. The results indicated that mixtures containing 2.5% flax shives or 7.5% starch ensured an optimal thermal performance, taking into account the mechanical strength of these products.

Assessment of thermal performance of different types of masonry bricks used in Saudi Arabia

This paper presents the assessment of thermal performance of nine types of clay brick and two types of concrete brick in use in Saudi Arabia. The results are based on the experimentally measured values of equivalent thermal conductivity. The analysis of the measured data showed that the addition of insulation material either within the masonry brick mix to make the brick more lightweight or through filling insulation material into the holes of masonry bricks increases the thermal resistance significantly. Red clay brick were found more thermally effective than concrete brick. Use of insulating mortar in building walls increases the thermal resistance compared to that of the walls prepared with ordinary concrete mortar. An economic analysis shows that the insulated clay brick (type 7) is the most effective among the types of brick studied as it has the lowest net present value (NPV) of 36.9 $/m 2. The load due to thermal transmission through a building envelope (walls and roof) constitutes an appreciable percent a building’s total thermal load. Therefore, long-term studies of the thermal performance of building materials should be conducted to establish thermally optimal brick for usage in building construction in the Kingdom of Saudi Arabia.

Hot-Box Testing of Building Envelope Assemblies—A Simplified Procedure for Estimation of Minimum Time of the Test

Cost of performing hot-box experiments on building envelope assemblies is relatively high. That is why proper estimation of the minimum amount of time necessary to achieve required test accuracy is critical to all hot-box operators. In this paper, two methods are proposed for determining wall specimen time constants, for the hot-box apparatus testing. The requirements published in ASTM C1363-05 “Standard Test Method for the Thermal Performance of Building Materials and Envelope Assemblies by Means of a Hot Box Apparatus,” concerning determination of the time to reach the steady state of heat flow are discussed. One method requires numerical calculations of the response factors with subsequent determination of time constants. The second method makes use of the approximate relation between the time constant and the product of resistance, capacity, and a structure factor. Both methods may serve for the optimization of the minimum test time during hot-box experiments.

Validation of Envelope Thermal Characteristics for an Existing Building

A genuine concern has been expressed in literature by the building engineers and architects about the in-use variations in thermal performance of building materials in general and of insulation in particular due to aging, shrinkage, settling, compression, etc. However, research ef forts to quantify these effects have been limited.