Thermal Insulation Of Buildings Research Articles

Application of SiO 2 Aerogel Material in Building Energy Saving Technology

SiO2 aerogel is a three-dimensional network structure solid materials, with the characteristics of low density, low thermal conductivity, high light transmittance, high porosity, high specific surface area and so on, but also has the excellent performance of fireproof and waterproof. It is a rare light, environmental protection, multifunctional material, which has great application prospects in the broad field of building thermal insulation. With the objective of building energy saving, this paper briefly describes the research on SiO2 aerogels, discusses the possibility of large-scale production from preparation of diverse raw materials, raw materials and drying cost reduction and so on, focuses on the application progress in building insulation of SiO2 aerogel glass and SiO2 aerogel thermal insulation coatings; then, from the point of view of the excellent characteristics, this paper presents the application of a SiO2 aerogel material in building energy saving technology, and from the SiO2 aerogel materials in thermal insulation, waterproof, fireproof and simplifying the construction process and other advantages, constructs the application system that SiO2 aerogel materials replace the current thermal insulation material in building energy saving. At last, it makes a conclusion and expectation of the SiO2 aerogel materials application prospect in building thermal insulation.

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

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 of thermal insulation of buildings, and their functionality in the long term, while taking into account local specifics and the preparation of environmental product declarations.

The Domestic Research Situation of Crop Straws as Building Wall Materials and Thermal Insulation Materials

At present, the comprehensive utilization of crop straws exist the problem of the lower industrial utilization in Jilin Province, China. It’s well-known that the industrial conversion of crop straws are often used as the building wall materials and thermal insulation materials in our country. According to the above two questions, this paper elaborates the domestic research situation of crop straws that serve as building wall materials and thermal insulation materials, and summarizes the fabrication process, mechanical property and thermal performance of the crop straws as building wall materials and thermal insulation materials. Finally, the article puts forward three key problems of crop straws, which are used as the building wall materials and thermal insulation materials. I hope that this paper can provide valuable reference for speeding up the comprehensive utilization of crop straws in Jilin Province.

Thermal performance of different exterior wall structures based on wall orientation

Heat transfer from opaque walls of buildings is very important for energy saving and providing thermal comfort in different climates. In this study, insulation models of opaque walls with different orientations and external, internal and sandwich materials were numerically analyzed in terms of their time-dependent thermal behaviors. The one-dimensional transient heat conduction equation was solved via the implicit finite difference method for summer and winter conditions and northern, southern, eastern and western orientations. Meteorological data for cities in Turkey with different climates, i.e., Ankara, Erzurum, İstanbul and İzmir, were used in these calculations. When the outside boundary conditions were defined by using January and July monthly averages of the daily data; the inside air temperature was assumed to be 20°C and 24°C in winter and summer. The results indicated that sandwich wall insulation produced more convenient heat loss and heat gain for each climate and direction. The standard deviations of the heat transfer values for the different directions were larger in summer than in winter because of the solar radiation effect. The numerical calculations for the sandwich wall applications were carried out for different insulation thicknesses namely 0.15m and 0.25m, and for an uninsulated wall; the results were also compared with Turkish directive on the thermal insulation of buildings, TS825 taken as a reference condition. Compared with the insulation thickness calculated based on the TS825, the heat loss and gain values could be decreased by up to 65% and 80% for the worst winter and summer conditions.

Multicriteria Analysis of Selected Building Thermal Insulation Solutions

Abstract The purpose of this paper is to present and analyse the decision-making problem faced by a future house owner - selection of the optimal solution of building thermal insulation in relation to the selected criteria, both related to costs and future benefits. The problem of selecting the best solutions in the construction sector is widely discussed in the science literature. In this paper, the authors decided to solve the raised problem by using the Entropy method.

Young’s modulus and thermophysical performances of bio-sourced materials based on date palm fibers

The present work is a part of a large project aimed at design and development of new composite materials containing date palm fibers (DPF) primarily suitable for thermal insulation in various sectors, especially in the building sector. On one hand, porosity (P) and Young’s modulus (E) of gypsum based composites reinforced with DPF were investigated. On other hand, thermal resistance and time lag of composites were also studied. The results showed that E of DPF reinforced gypsum materials is mainly affected by the interfacial adhesion between matrix and DPF. The effect of DPF sizes and loadings is highly significant on the stiffness of gypsum. It’s noted that the adding of DPF on gypsum induces an increase of both time lag and thermal resistance of composites. This new biocomposite can be used as a raw material for reinforcement gypsum materials in order to produce a friendly biocomposite materials to use for thermal insulation in buildings.

The environmental impacts of thermal insulation of buildings including the categories of damage: A Polish case study

Households have a big impact on energy efficiency in Poland. About 80% of final energy in the construction sector is used for heating buildings. Due to the significant role which is assigned to the thermal modernization in European documents, the paper attempts to assess the environmental benefits of the investment consisting of thermal insulation of the building external vertical walls, with the use of LCA analysis and divided into three categories of damage. A methodology for assessing the benefits has been proposed and the analyses for different variants have been performed, including the condition of the building before thermal insulation, the used heat source, the type of thermal insulation and the climatic zone in which the building is located. It has been shown that the investment, for all examined variants, is beneficial for environmental reasons. In the worst case, the reduction of the burden on the environment as a result of the investment occurs after 5 years, while in most cases only after one year. The obtained environmental benefits depend primarily on the condition of the building before thermal insulation and the used heat source. The greater are the advantages, the bigger is the demand for thermal energy of the building that also depends on the climate zone. Because of the thermal insulation material the greatest environmental benefits are found in the case of ecofibre. Taking into account three categories of damage, the greatest benefits were achieved in the Resources category.

Study on ecological cost-effectiveness for the thermal insulation of building external vertical walls in Poland

Improving the energy efficiency of buildings is not a new issue. It is a challenge not only in Poland but also in many other European countries, which is proved by the actions and initiatives taken by the European Union. Due to the fact that Poland lies in a warm moderate temperate zone, with transition to the impact of marine and continental climate, the issue of thermal insulation of buildings is important in terms of economy and ecology. The paper proposes a method and an analysis of the ecological cost-effectiveness for the investment involving the thermal insulation of external vertical walls for two different buildings in five climate zones located in Poland. The authors based their study on the life cycle assessment (LCA) technique. The analysis took into account different components, such as: heat sources, thermal insulation and construction materials, and usable areas of the analyzed buildings. Popular building materials on the Polish market, and more, were also included. The studies were performed on two single-family houses with a similar usable area, which are representative on the European market. The most favourable values of ecological cost-effectiveness were obtained among the examined options for most ecological thermal insulation material (eco-fibre), the type of heating with the highest environmental impact (electricity) and the most extreme (cold) climate occurring in Poland. The ecological payback period of thermal insulation investment for the studied variants were obtained in the range 0–6 years. The proposed method proved to be very helpful in assessing various options for thermal insulation investments. It can also be used in other places in the world. It allows to take into account both the environmental and economic aspects of the investment. This method could be useful for designers and energy/environmental auditors.

Research on the Application of Building Information Model Technology in the Design of Urban Residential Buildings in Cold Region

The design of urban residential buildings in cold region is different from that in low latitude region, or the design of general public buildings. The precise grasp of dwelling unit type and appearance style, effective control of building heating and thermal insulation efficiency and the implementation of the sustainable concept of low cost construction and environmental protection are dependent on the early scientific and rational design. And the building information model technology just acts as a platform for the optimization of the design. The study is based on the engineering projects; the planning, the design of building facade, collision detection optimization and the full participation of construction cost control in building information model provide a new train of thoughts and research reference for the residential design in cold region, in the context of the digital age, and to a certain extent, the study looks forward to the future urban residential design and construction industrialization prospect in the cold region . Building information modeling technology improves the design efficiency and quality with its precise data processing and analysis, avoids the defects in design and the material waste of construction and environment pollution, significantly enhancing the pre-processing level of construction structure parts, which is in line with the energy-saving environmental protection and rural environmental construction philosophy advocated by the state, and the green building strategies of sustainable development.

Preparation and properties of a polyvinyl alcohol toughened urea-formaldehyde foam for thermal insulation applications

Urea-formaldehyde (UF) foam exhibits excellent flame-retardant properties and low thermal conductivity. These properties make it suitable for thermal insulation in buildings. However, the brittleness of this material is its biggest disadvantage. In this study, polyvinyl alcohol (PVA) was used to improve the toughness of UF foam. The effect of the amount of PVA addition on the properties of the UF foam, such as the apparent densities, foaming ratio, compression strength, microstructure, fragility, limited oxygen index and thermal conductivity, were studied. The best performance was obtained for PVA modified UF foam with 1.5wt.% added PVA. The pyrolysis characteristics of the 1.5wt.% PVA modified UF foam were investigated using thermogravimetric analysis coupled with Fourier transform infrared spectroscopy. Emissions of CO2, ammonia and isocyanic acid were identified during pyrolysis. By comparing the combustion and pyrolysis derivative thermogravimetry (DTG) curves, the effects of the presence of oxygen on the thermal decomposition were observed.

Effect of nano vacuum insulation panel and nanogel glazing on the energy performance of office building

Nanotechnology has proved to be a promising candidate for thermal insulation of buildings. Nano aerogel and nano vacuum insulation panel (VIP) have been widely explored in the recent past, and their viability in buildings remains an ongoing research challenge. Even though a lot of works have been reported from around the globe, the Gulf Cooperative Council (GCC) region, particularly the Kingdom of Saudi Arabia (KSA) – a leading building construction market in the world, has a wide scope of research in this area. This article presents a simulation study on the energy performance of a prototype office building in KSA, by replacing the conventional polystyrene insulation and double-glazing with nano VIP and nano aerogel (nanogel) glazing. The building model was built in Autodesk Revit (version 2015), and the energy simulation was performed by ECOTECT software (version 2011) by using the weather data of Dhahran. Considering polystyrene insulation in walls and roof and double-glazed windows as the base case, nanogel and nano VIP were employed individually, and in combinations of window, wall and roof. The results show that, compared to the base case, the nano VIP in walls and roof and nanogel glazing in windows could jointly save about 18% of annual energy consumption of the building, wherein the contribution of nanogel glazing alone is 16% for the setpoint temperature (ST) band of 19–27°C. The sensitivity analysis has revealed that the energy saving potential of the nanogel glazing is sensitive to the ST band.

Environmental implications of the use of agglomerated cork as thermal insulation in buildings

The market for insulation material is playing a crucial role in Europe's energy transformation, due to its influence on energy consumption in buildings. The introduction of renewable materials for thermal insulation is recent, and little is known so far about its environmental implications. This study analyses the environmental performance of a cork insulation board, made of agglomerated cork from forestry cork wastes, by means of cradle-to-gate Life Cycle Assessment methodology. The results indicate that the use of natural insulation materials does not necessarily imply a reduction of environmental impacts due to manufacturing processes with a low technological development. In this case, the most influential stage is the manufacturing stage, in which the board agglomeration and the cork trituration have the highest impacts. The most influential inputs are both the transport used during the life cycle and the large quantities of electricity and diesel in the manufacturing stage. Some strategies have been identified to reduce the environmental impact, such as promote the acquisition of local raw cork to reduce transportation from the manufacturer, improve the efficiency and productivity of manufacturing processes and improve the product design to help increase its market share. Moreover, the inclusion of biogenic carbon contained in forest-based building materials affects the Global Warming Potential results considerably. However, it is very important to consider how this biogenic carbon is calculated and how the product is managed after its lifetime.

Characterization and reactivity of sodium aluminoborosilicate glass fiber surfaces

Multicomponent complex oxides, such as sodium aluminoborosilicate glass fibers, are important materials used for thermal insulation in buildings and homes. Although the surface properties of single oxides, such as silica, have been extensively studied, less is known about the distribution of reactive sites at the surface of multicomponent oxides. Here, we investigated the reactivity of sodium aluminoborosilicate glass fiber surfaces for better understanding of their interface chemistry and bonding with acrylic polymers. Acetic acid (with and without a 13C enrichment) was used as a probe representative of the carboxylic functional groups in many acrylic polymers and adhesives. Inverse gas chromatography coupled to a mass spectrometer (IGC–MS), and solid state nuclear magnetic resonance (NMR), were used to characterize the fiber surface reactions and surface chemical structure. In this way, we discovered that both sodium ions in the glass surface, as well as sodium carbonate salts that formed on the surface due to the intrinsic reactivity of this glass in humid air, are primary sites of interaction with the carboxylic acid. Surface analysis by X-ray photoelectron spectroscopy (XPS) confirmed the presence of sodium carbonates on these surfaces. Computer simulations of the interactions between the reactive sites on the glass fiber surface with acetic acid were performed to evaluate energetically favorable reactions. The adsorption reactions with sodium in the glass structure provide adhesive bonding sites, whereas the reaction with the sodium carbonate consumes the acid to form sodium-carboxylate, H2O and CO2 without any contribution to chemical bonding at the interface.

Positioning of an isothermal heat storage layer in a building wall exposed to the external environment

The paper presents an idea for the enhancement of a building's thermal insulation component by adding into the structure a thin layer of a phase-change material (PCM). The proposed solution can be dedicated, for example, to an external partition of lightweight construction. The capacity for latent heat storage allowed it to stabilize the temperature inside the insulation layer in a daily cycle and to minimize the temperature difference between the internal and external surfaces. In this paper, different positions of a PCM layer in the thermal insulation of an external wall were analysed. The main goal of this work was to find the best position of the PCM layer, taking into account the indoor temperature and the meteorological conditions. The authors propose two parameters: the amount of stored energy and the dynamism of the charging/discharging processes. Taking into account large temperature fluctuations on the external surface during summer and winter, it was concluded that, for this specific case, the most appropriate solution would be an external position of the PCM with a melting temperature of 20°C.

Study of the Thermal and Mechanical Performance of Laterite Blocks Mixed with Néré Pod for the Thermal Insulation of Buildings

Study of the Thermal and Mechanical Performance of Laterite Blocks Mixed with Néré Pod for the Thermal Insulation of Buildings

A Comparison of Banana Fiber Thermal Insulation with Conventional Building Thermal Insulation

A Comparison of Banana Fiber Thermal Insulation with Conventional Building Thermal Insulation

Development of Durable Exterior Insulation Finishing Systems Based on Composite Timber Technology for Building Facades

Today, the requirements to thermal insulation of buildings and structures are increasing. Insulation has become an essential part of regulatory thermal protection of buildings. The analysis of the advantages and drawbacks of the existing insulation systems has shown that the most suitable system is the one with the insulation layer located outside the building. Such system of insulation is based on the use of an additional layer, called finishing or cladding, placed on top of the insulation layer to ensure the protection of buildings against atmospheric agents. The purpose of this study was to develop a material for exterior finish cladding of buildings. We developed a composite timber cladding system in the form of laminated composite material consisting of a substrate (base), a binder and a decorative layer. Manufacturing process comprised four stages. Atmospheric effects were modeled according to the GOST climatic test methods. For the rational use of material resources we calculated the optimal material consumption per unit area for the decorative layer. Durability of cladding depends on the substrate material. Under the effect of atmospheric agent the durability of cladding decreases. Heat and ultraviolet exposure causes decrease in durability of cladding after the completion of resin polymerization, which initially leads to an increase in durability. The impact of aggressive media solutions also results in reduced durability of cladding. Durability of cladding depends on the strength characteristics of the substrate. An operation life of cladding is determined by the difference between the mass of cladding with optimal material consumption per unit area for the decorative layer and the mass of similar cladding with the least possible material consumption per unit area for the decorative layer from an aesthetic perspective. The operational life of the developed cladding is at least 15 years. The cement chipboard-resin compound has low adhesive strength, which leads to the conclusion about the impossibility of using cement chipboard as the substrate for decorative cladding. High humidity deformation limits the use of wood particleboards and MDF as a substrate for cladding. Thus, we recommend using WBP plywood as a substrate for the cladding. The economic rationale is based on the comparison of the following materials used for exterior finishing systems: plywood, facing bricks, porcelain stoneware and vinyl siding.

Use of bottom ash from olive pomace combustion in the production of eco-friendly fired clay bricks

Olive pomace bottom ash was used to replace different amounts (10–50wt%) of clay in brick manufacturing. The aim of this study is both studying bricks properties and showing a new way of olive pomace bottom ash recycling. Properties of waste bricks were compared to conventional products following standard procedures in order to determine the maximum waste percentage. The amount of olive pomace bottom ash is limited to 20wt%, obtaining bricks with superior engineering properties when 10wt% of waste is added. Adding higher amount of waste (30–50wt%) resulted in bricks with water absorption and compressive strength values on the edge of meeting those established by standards. Therefore, the addition of 10 and 20wt% of olive pomace bottom ash produced bricks with a bulk density of 1635 and 1527kg/m3 and a compressive strength of 33.9MPa and 14.2MPa, respectively. Fired bricks fulfil standards requirements for clay masonry units, offering, at the same time, better thermal insulation of buildings due to a reduction in thermal conductivity of 14.4% and 16.8% respectively, compared to control bricks (only clay).

The Effect Of Thermal Insulation Of An Apartment Building On The Thermo-Hydraulic Stability Of Its Heating System

Abstract The contribution aims to investigate the effect of the decreased thermal losses of an apartment building due to the thermal insulation of opaque external building constructions and the replacement of transparent constructions. It emphasizes the effect of the thermal characteristics of external constructions on the functionality of the existing heating system in the building and the related requirements for the renovation of the heating system in order to ensure the hydraulic stability of the system and the thermal comfort of the inhabitants.

Performance criteria for the fire safe use of thermal insulation in buildings

Building design can be considered as a multi-objective optimisation problem, in which many criteria are considered for determining the most favourable solution. The application of optimisation techniques requires the design criteria to be quantifiable, which sets the baseline for the application of performance-based designs. Sustainability has become the main driver in the built environment during recent decades, with energy efficiency becoming the foremost design criteria and appropriately quantified. By contrast, the approach taken for fire safety is much simplistic, relying on a series of prescriptions based on material classification and “pass–fail” criteria defined in standard fire tests. This results in deficiencies in identification of fire hazards and undermines any attempt at design optimisation. A redefinition of the failure criteria framework based on fundamental understanding of the material behaviour, including the heat transfer controlled processes governing the onset of pyrolysis, can provide a performance-based methodology for the fire safe use of insulation materials in buildings. The different hazards from insulation materials in fire are identified and a set of criteria are defined to identify likely failure modes. A series of highly instrumented large-scale experiments of a construction system involving a common combustible material are referenced to demonstrate the proposed methodology.