Thermal Insulation Of Buildings Research Articles

The design of a novel approach for the assessment of thermal insulation in buildings using infrared thermography and artificial intelligence

Buildings consume high energy for space and water heating and thereby contribute largely to greenhouse gas emission. Improving thermal insulation of building's walls can significantly reduce energy consumption for space heating as well as decrease greenhouse gas emission. However, prior to the retrofitting of a building it is required to evaluate the current level of wall insulation, as over insulation will increase the cost of insulation and decrease the expected energy savings and hence, causing a lengthy payback period. Infrared thermography is a very effective tool in evaluating building's thermal performance when a reasonable temperature gradient exists between indoor and outdoor environment. This paper presents a novel design which involves using a low resolution infrared camera with single point heating system from which the thermal conductivity and thermal insulation of building's wall can be categorised and estimated. An experimental study has been conducted on different sample wall sections and an artificial neural network is used to analyse the infrared images of walls for categorisation based on the level of wall insulation. The result shows 88% overall accuracy in categorising the wall types based on their level of insulation from a set of infrared images.

Development and characterization of sustainable lightweight geopolymer composites

Abstract Production of lightweight building materials attract the attention of the scientists worldwide with the need for reducing the structure deadweight, provide better thermal insulation for buildings, and cost less to transport. The current work focused on the production of lightweight geopolymer composites by the incorporation of aluminum powder and aluminum slag in various ratios for water-cooled slag/kaolinite sand composite; the activators used were 6% of equal ratio from sodium hydroxide and sodium silicate. The properties of the produced lightweight geopolymer composites were studied by measurement of compressive strength, bulk density, water absorption, FTIR, XRD and SEM imaging. Results showed the enhancement for both physicomechanical and microstructural characteristics with using aluminum powder and aluminum slag forming lightweight composites with densities below 2.15 g/cm3 depending on the studied mix composition.

О КАЧЕСТВЕ НОРМИРОВАНИЯ ТЕПЛОЗАЩИТЫ ЗДАНИЙ

Considered relevant the problem of quality regulatory documentation for thermal protection of buildings, not only depends on the quality of the thermal protection designed buildings but also ensuring favourable hygienic conditions in the premises, as well as reliability and cost of enclosing structures. Provides a critical analysis of existing regulations on heat-shielding of buildings for compliance with the requirements of technical regulations on safety of buildings and constructions (FZ 384)-creation of thermal comfort indoors and ensure constructive reliability of external walling during the cold period of the year. It is noted that the existing regulations on heat shielding buildings incorrectly defined the main objective of the thermal insulation of buildings. How to ensure a given level of heat energy consumption. Critically analyzed the main sections of the existing regulations and proposed methods of Thermo-physical parameters of rationing of exterior fencing of buildings in which priority is energy conservation and ensuring thermal comfort in rooms, the main criterion which is established by specialists the difference between the room temperature and the temperature of the inner surface of the outer fence. Offered a simple and reliable technique for regulation of water resistance design that provides no moisture accumulation in constructions during the cold period of the year. The technique of integrated calculation of heat and vapor barrier layers of multilayer enclosing structures, Thermo-physical properties which meet regulatory requirements

Positive and Negative Aspects of ETICS

Thermal insulation of buildings brings the social benefits mainly through energy savings. However, the risk of producing undesirable negative impacts on the environment and the health of the population is not negligible. Proper selection of the appropriate variant and product should include an assessment not only of the thermal, technical, operational, economic but also health and environmental aspects. In assessing the environmental and health impacts, only CO and sulfur emissions are often evaluated. The impact of other very dangerous chemicals released during the production of ETICS components and subsequently during the operation of the building is investigated only marginally. This aspect will be given the utmost attention and individual variants will be carefully examined also in this point of view. The public does not usually have enough quality data on the various available ETICS variants. The chosen method of thermal insulation should also be felt by the user in a positive way, which will contribute to the comfort and high standard of living.

Analysis of Thermal Insulation Building Materials Based on Natural Fibers

Abstract In recent decades, there has been growing concern about protecting the environment through all possible methods, and the area concerned is that of constructions because they are the largest energy consumer and the largest producer of waste. In this context, the present paper proposes new thermal insulation materials based on natural fibers, sheep wool and hemp, which are renewable resources, with increased availability at national level. The thermal characteristics of the composite materials were followed the aim being to obtain materials with thermal insulation properties superior to those existing on the market and consequently to increase the energy efficiency of the buildings.

Renewable Insulation materials constructed from Colombian materials according to the principles of Sustainable Development: a review of possibilities

The growing demand for building materials requires the development of environmentally friendly materials with excellent use properties and reasonable prices. One of the major objectives of materials research in the construction industry is the use of renewable resources from waste materials from industries for the development of new building materials. The current trend of thermal insulation of buildings has resulted in the development of materials for insulation based on renewable resources of agriculture. This article describes the research and development of insulation materials based on natural fibres of agricultural origin; in particular, guadua fibres, sugar cane, hemp, flax and jute.

Telhados verdes como alternativa para construções sustentáveis

O telhado verde tem sido considerado como alternativa para mitigar alguns problemas ambientais presentes nos centros urbanos, como enchentes, poluição do ar e sonora, e ilhas de calor. Além disso, pode atuar como isolante térmico em edifícios proporcionando conforto térmico e economia de energia. Entretanto, uma das desvantagens é o seu elevado custo de implantação. Este trabalho apresenta uma pesquisa experimental realizada em Limeira, São Paulo, com o objetivo de avaliar dois aspectos de telhados verdes: seu custo de implantação e seu desempenho como isolante térmico na região de estudo. Para a composição de preços, foram considerados os principais sistemas construtivos de telhado verde, orçados por m-² em empresas especializadas e como materiais unitários no comércio local, obtendo-se variações de valor de até 835%. Para a análise de desempenho térmico, foram construídos três módulos experimentais (M), sendo o M1 apenas com laje de concreto impermeabilizada (telhado de controle), e os outros dois com sistemas de telhado verde extensivo: o M2 utilizando Chlorophytum comosum e o M3 com Hemigrafis alternata. O controle de temperatura e umidade interior e exterior nos módulos foi realizado com termohigrômetros (Testo 174 h data logger) a partir de medições a cada 10 minutos durante 40 dias. Com esta análise pode-se atestar o melhor desempenho térmico das coberturas vegetadas (M2 e M3), que apresentaram temperaturas máximas até 3,4°C inferiores àquelas do M1 (controle). Conclui-se que, apesar do custo de implantação ainda ser elevado, o telhado verde, é viável, pois possui benefícios ambientais e de conforto térmico e pode levar à diminuição do consumo de energia elétrica.

Use of Modern Technology to Develop Investment Housing Projects in Iraq

Abstract The problem of housing is one of the most important problems in Iraq, especially with the increase in the rate of population growth which is one of the highest rates in the world and after the great destruction that happened in Iraq because of wars and terrorist acts, and here begins to think about the real solutions of this crisis using modern technology and taking into account the feasibility of using modern construction materials compared to the traditional method of construction. Investors are seriously considering changing the traditional building style and transition to modern building materials to increase quality, win a time, ease of installation and achieve dimensional consistency with ease of internal and external finishing work. The hot weather in Iraq requires real attention to the issue of thermal insulation of buildings and therefore can use the advantage of modern materials to increase thermal insulation and reduce in the energy consumption. This article sheds light on the investment housing projects in Baghdad city.

The Formation of a Comfortable Habitat and the Economic Feasibility of Using Alternative Thermal Insulation Technologies

The pace of construction and renovation of buildings is increasing every year. This encourages the search and introduction of new materials and technologies to improve the comfort of housing. An important problem is also the need to ensure the energy efficiency of buildings. A peculiarity of the Russian natural conditions is a significant daily and annual difference in atmospheric temperatures. The use of various thermal insulation materials in the construction process will significantly reduce the cost of maintaining buildings and provide comfortable conditions for people, regardless of natural events. In addition, the use of certain facade treatments solves the aesthetic problem and can protect against precipitation and industrial emissions. Therefore, the purpose of this study is to find additional possibilities for thermal insulation of buildings using non-traditional technologies and materials. Modern approaches to the aesthetics of buildings involve the use of expensive mineral thermal insulation materials. Reducing the cost of their manufacture is possible through the use of industrial waste. Wastes from non-ferrous metallurgy are suitable for the production of slag wool or for the production of slag glass-ceramics. A wide range of possibilities allows the use of various wastes in the manufacture of bricks to increase porosity, strength and frost resistance. The use of a number of additives also provides an increase in economic efficiency and environmental friendliness of production. The use of special coatings for gypsum finishing materials could increase their strength and water resistance. The quality of facade paints is significantly increased when using aluminum silicate liquid sodium glass. Fine-dispersed waste of metallurgical enterprises will allow to lower the cost of production of liquid glass and aluminosilicate glue. The use, obtained from waste, astringent, provides for the production of heat-insulating materials the production of bright colors without the use of pigments. High strength and water resistance of materials can ensure the use of magnesian waste. Keywords: thermal insulation, energy efficiency, industrial waste, building materials, finishing materials, paints.

FEASIBILITY ANALYSIS OF THE USE OF RIGID POLYURETHANE FOAM IN MODULAR SANDWICH PANELS FOR RAPID ASSEMBLY STRUCTURES

Mobile and rapidly assembled structures play an important role in building temporary and semipermanent accommodations and shelters in post-disaster management. One of the most efficient construction systems that can be used in rapidly assembled buildings is lightweight panelized systems. Use of rapidly assembled panelized systems is becoming very popular for cutting the construction time and transportation costs that make them suitable options for rapid assembly construction. In addition, when acoustic and thermal insulation of buildings is important, foam filled composite sandwich panels are an effective solution. Soft, semi-rigid and rigid Polyurethane (PU) foams, which are first introduced into the market in the 1950s, are most popular types of foams. Regarding the research performed in the last decade, the structural behavior of PUfoam filled sandwich panels has been investigated by several researchers worldwide. There is a need for a comprehensive feasibility studies on the use of rigid PU foam in structural sandwich panel cores so that various aspects of this material is deeply investigated. In this paper, a feasibility study carried out on a commercial type of rigid PU foam with trading name AUW763, to be used as the core material of sandwich panels, based on ASTM E1730-15. Results show AUW763 meets the standards requirements and specifications for building constructions.

Assessment of waste clays in the Qusseir region of east central Egypt for production of lightweight bricks

BackgroundEgyptian Upper Cretaceous waste clay samples from Yunis Mines, Qusseir vicinity, Eastern Desert, were investigated for their chemical and mineralogical compositions as well as for firing. These investigations were carried out to assess the suitability to use the waste clays for the production of lightweight bricks. X-ray fluorescence (XRF), scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared (FTIR) techniques were applied for characterizing chemical and mineral compositions of the raw clays. On the other side, densification parameters of the fired samples up to 1100 °C were examined by using Archimedes water-saturation methods and by determining the density and crushing strength of the fired bodies.ResultsTwo types of concrete were prepared using different grain sizes: coarse and a mix of coarse and fine aggregates. Concrete batches were prepared, and the mechanical strength and the bulk density were determined. Mineralogically, the waste samples consist of montmorillonite as the predominant clay mineral, with quartz, calcite, fluorapatite, anhydrite, and pyrite as impurities. Bulk density and apparent porosity of the fired clay sample at 1100 °C were 0.89 g/cm3 and 67.19%, respectively, while the bulk density of the two types of concrete range from 0.76 g/cm3 in coarse type with no fines to 0.90 g/cm3 in the coarse with 20% fine fraction. The crushing strength of both types is 25 kg/cm2 for coarse type and 45 kg/cm2 for coarse and fine types, respectively.ConclusionsThe results showed that the data provides a useful application of waste clay ramps of ancient Yunis mining tunnels in Qussier area with an additional mean to assess their suitability for the production of lightweight brick concretes to reduce density and their relatively good strength in modern buildings for non-loading building units and to enhance the thermal insulation of buildings.

العزل الحراري کأداة لترشيد استهلاک الطاقة - دراسة لترشيد استهلاک الطاقة بالمباني السکنية للمناطق الحارة الجافه Thermal insulation as a tool for energy conservation Study to rationalize energy consumption in residential buildings of dry hot areas

تعد کفاءة الطاقة من أهم المحاور التى يتم مناقشتها والعمل على تفعيلها فى المباني فى معظم دول العالم؛ وحيث أن العزل الحراري في المباني السکنية يشکل الأداة الرئيسية لتحسين کفاءة استهلاک الطاقة؛ وتطورت مواد العزل الحراري ليس فقط من حيث الخصائص الحرارية، ولکن أيضا فيما يتعلق بتحقيق جودة البيئية الداخلية والتأثير البيئي. وتظهر إشکالية البحث في أن التحديات تفرض نفسها بالرغبة في تخفيض استهلاک الطاقة مع تحقيق راحة المستخدمين، لإيجاد الحلول التي تقدمها مفاهيم التحکم الحراري في قدرتها على تجاوز مثل هذه التحديات بالرغم من أن هناک الکثير من التناقضات في معايير تصميم المباني المستدامة التي تحافظ على البيئة الداخلية للمسکن بشکل يؤدي لتحسين الاداء الحراري في المسکن وبالتالي تحقيق الراحة الحرارية للمستخدمين مع ترشيد استهلاک الطاقة. ويهدف البحث الى ترشيد استهلاک الطاقة للمباني السکنية من خلال استخدام مواد العزل الحرارى لعناصر الغلاف الخارجي للمبنى کما يهدف لحماية البيئة في التقليل من إنبعاثات غاز(CO2) الناتجة عن استهلاک الطاقة المستخدمة لأغراض تدفئة وتبريد المباني السکنية مع تحقيق الراحة الحرارية داخل المباني لشاغليها.Energy efficiency is one of the most important topics to be discussed and activated in buildings in most countries of the world. Thermal insulation in residential buildings is the main tool for improving the efficiency of energy consumption. Thermal insulation materials have developed not only in terms of thermal properties but also in terms of internal environmental quality and environmental impact.The research problem shows that the challenges impose themselves on the desire to reduce energy consumption without sacrificing the comfort of users, to find the solutions offered by the concepts of thermal control in their ability to overcome such challenges, although there are many contradictions in the standards of design buildings that maintain sustainable internal environment To improve the thermal performance of the dwelling and achieve thermal comfort of users with energy conservationThe research aims to rationalize energy consumption in residential buildings through the use of thermal insulation materials for the building envelope. It also aims to protect the environment by reducing the CO2 emissions such as resulting from the consumption of energy used for the heating and cooling of residential buildings. And the indoor health environment for occupants, which will increase their activity, work, and production.

Cellulose Aerogels for Thermal Insulation in Buildings: Trends and Challenges

Cellulose-based aerogels hold the potential to become a cost-effective bio-based solution for thermal insulation in buildings. Low thermal conductivities (<0.025 W·m−1·K−1) are achieved through a decrease in gaseous phase contribution, exploiting the Knudsen effect. However, several challenges need to be overcome: production energy demand and cost, moisture sensitivity, flammability, and thermal stability. Herein, a description and discussion of current trends and challenges in cellulose aerogel research for thermal insulation are presented, gathered from studies reported within the last five years. The text is divided into three main sections: (i) an overview of thermal performance of cellulose aerogels, (ii) an identification of challenges and possible solutions for cellulose aerogel thermal insulation, and (iii) a brief description of cellulose/silica aerogels.

Hygrothermal and Acoustical Performance of Starch-Beet Pulp Composites for Building Thermal Insulation.

This article deals with the elaboration and the characterization of an innovative 100% plant-based green composite made solely of beet pulp (BP) and potato starch (S). Using this type of material in insulation applications seems a good solution to reduce the CO2 gas emissions in building. The influence of the starch amount on composite characteristics was studied. Four mixtures were considered with different S/BP mass ratios (0.1, 0.2, 0.3 and 0.4). The physical properties of these materials were studied in terms of porosity, apparent and absolute densities, thermal conductivity, and hygric properties. The influence of humidity content on acoustical properties was studied as a function of frequency. Test results show a real impact of both starch and humidity contents on the hygrothermal and acoustical properties of the studied material due to the porosity. The composite with the lowest amount of starch (S/BP = 0.1) seems to be the optimal composition in terms of the hygrothermal and acoustical behaviors.

Inwards Doors Blocked by Fire Induced Overpressure in Airtight Apartment: a Real Case in Germany

Nowadays, construction requirements and practices are rapidly moving towards more airtight building envelopes, thermal insulation and energy saving according to the Energy Performance of Buildings Directive. In such structures, one might wonder if there are specific risks in case of fire. Some fatal accidents during the intervention of fire brigades were reported in the past due to a backdraft phenomenon in airtight and insulated renovated apartment. However, the occupants of better insulated and sealed buildings can also be exposed to news kinds of hazards. This paper presents the fire that occurred in an apartment in Germany on the 5 February 2013. This fire broke out during night in an apartment in a newly renovated building to meet the passive standard. Awakened by the noise of the flames, the occupant of the apartment quickly noticed that a fire had just broken out in his living room. After an unsuccessful attempt at fire extinction, he decided to abandon his dwelling. Unfortunately, the inwards-opening door to reach the outside via the corridor turned out to be completely blocked. After an interminable waiting period estimated by the investigators of nearly two minutes the occupant was finally able to open the bedroom door leading to the balcony where he was rescued by the emergency services and escaped with burns. After some investigations and based on fire simulations results from CFAST modeling, it was concluded that the door were blocked due to the fire induced overpressure.From this real fire case there is no doubt about the capacity of the building structure to withstand high levels of overpressure, the integrity of the sealing of the passive house being not deteriorated in the first moments of the fire. This new fire hazard has to be taken into account in the fire safety design of confined dwellings.

Development of novel building composites based on hemp and multi-functional silica matrix

This study focuses on the development of novel bio-composites using a silica matrix that provides dual functionality: as a hydrophobic surface treatment and as a binder for hemp-shiv. The hydrophilic nature of hemp shiv, a plant based aggregate, results in composites having poor interfacial adhesion, weak mechanical properties and long drying times. In this work, sol-gel process has been utilised to manufacture durable low density hemp based composites. Morphological characterisation by scanning electron microscopy (SEM) showed that hemp shiv was embedded well in the matrix. Detailed chemical analysis using x-ray photoelectron spectroscopy (XPS) and gas chromatography-mass spectrometry (GC-MS) indicate the presence of water soluble and ethanol soluble extractives leached from the hemp shiv which are incorporated into the silica matrix inducing the binding effect. The composites were water resistant and showed good mechanical performance having the potential to develop novel thermal insulation building materials.

Prediction method of the long-term thermal performance of Vacuum Insulation Panels installed in building thermal insulation applications

Vacuum Insulation Panels (VIPs) are super-insulating products that can be used for different applications. When they are used for building thermal insulation, they have to maintain a very high thermal performance in long-term. The initial thermal conductivity of VIPs is around 4 mW.m−1.K−1. This very low value will increase in time, depending on the nanoporous property of the core material and on the barrier envelope efficiency which prevents the increase of moisture and internal pressure. To estimate the long-term thermal performance of VIPs, modelling is required. Simulations have shown the very great importance of the core material characteristics, and the external temperature and humidity conditions. That is why it is necessary to study the VIPs behaviour with realistic solicitations in service life for each VIP configuration. This paper proposes a methodology for determining the long-term thermal performance of VIPs when they are installed in envelope components for various building thermal insulation applications. All the methodology including the climate conditions, the building modelling and the insulation systems, is described. Severity criteria and performance indicators are proposed in order to estimate the thermal efficiency of VIPs in various applications and climates.

Energy Efficiency of “Green Structures” in Cooling Period

The proposed methodology for estimating the reduction of CO2 emissions by green constructions (green roof and facade greening) due to the “cooling effect” during the cooling period allows to calculate CO2 savings in warm periods of the year. For Kyiv, in July, the reduction of CO2 emissions per m2 at coal using is 133 g / m2, during the warm period of the year – 515 g / m2; using gas – 78 g / m2 and 303 g / m2. It is established that the energy savings of a green roof depends on the thickness of the thermal insulation of buildings: the thicker insulation causes the less green roof contribution to energy savings. However, the significance of their effectiveness remains. Green roofs can be especially effective in switching from gas to local solid fuels: peat waste, pellets, etc. As a practical recommendation, it is proposed to coordinate the placement of greened and ungreen parts of the green roof with rooms under the roof, which allows to reduce the refrigeration load on air conditioning. In addition, recommendations on grass care on the green roof have been developed. To maximize the cooling effect, it is necessary to maintain grass height no more than120 mm. Before the beginning of the transition period, it is necessary to stop mowing the grass, which reduces the cooling effect.

Measuring thermal conductivity of green-walls components in controlled conditions

This study is the first stage of a larger multidisciplinary research program about the environmental performances and functions of green walls in urban ecosystems. It aims to determine how green-walls contribute to the thermal insulation of buildings by measuring the thermal conductivities of green-walls’ components in controlled conditions. The study focused on complex green-wall systems, i.e. with a structure containing substrate in opposition with green-walls based on climbing plants. The four substrates were materials found in commercial substrate combinations. To compare, the thermal conductivities on two plants are carried out. In dry conditions, they showed conductivities of 0.062 W/m °C for sphagnum moss (Sphagnum cristatum), 0.060W/m °C for outdoor planting mix, and 0.105 W/m °C for clay balls and 0.051 W/m °C for substrate from a green-wall. Vegetation conductivities were also measured for ivy (Hedera helix) and Virginia creeper (Parthenocissus quinquefolia). As expected, conductivities were quite high (between 0.220 and 0.274 W/m °C). With the building thermal simulation, green-walls are technically able to improve buildings’ insulation.

Wood waste as an alternative thermal insulation for buildings

Current insulation materials in the construction market, which are predominantly inorganic materials, have a high performance in relation to heat transfer, i.e. high R-values, but the environmental impacts in their production processes are significant. The use of bio-based natural fibre materials such as cork, cotton, wood fibre, hemp, etc. with their lower embodied energy, moisture buffering capacity and, consequently, improved Indoor Environmental Quality have received increasing focus in both research and application, particularly amongst environmentally-conscious clients and designers.In this study a natural fibre material in the form of wood waste is examined experimentally to assess its suitability for use as a thermal insulation material, without the addition of any binder, within a timber frame wall construction. The wood waste is from primary production sources using untreated material. According to our experimental results, the thermal conductivity values of wood waste with different densities, ranged from 0.048 to 0.055 W/mK. These values are slightly higher than commonly used inorganic based insulation materials, although comparable to other natural insulation materials in the market, but have the economic advantage of being a low-cost by-product. The values relating to the material hygric performance including the water vapour diffusion resistance factor, water vapour permeability, and water absorption coefficient were also determined and presented, which will help facilitate future hygrothermal modelling.