Thermal Performance of Building Envelope (original) (raw)
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IJERT-Thermal Performance of Building Envelope
International Journal of Engineering Research and Technology (IJERT), 2020
https://www.ijert.org/thermal-performance-of-building-envelope https://www.ijert.org/research/thermal-performance-of-building-envelope-IJERTV9IS070653.pdf In the era of raising environmental problems, built structures are considered as one of the main energy consuming entities which are ultimately responsible for environmental degradation. To handle the issue it is important to deal with building's energy demand which is mainly due to extreme weather conditions. Building envelope is the first to encounter with weather thus it plays a major role in deciding building's energy demand. This paper deals with the improvement of thermal performance of Building Envelope according to climate, indices and local solar time of region .This paper also focus on new facades technologies which lower down the building's energy demand with better insulation. To achieve this goal an integrated approach is required which comprise techniques, technologies, architectural innovation all together. These facades also have benefits other than energy saving. Numerous technologies are being developed to generate energy also.
Thermal Insulation of Building Envelope for Ecological Conservation
2021
Sustainability has been a rising concern for facility projects since the early 1990s. It is conscious that in terms of carbon emissions, energy usage, water use, utilisation of raw materials, waste production and many other factors, construction and operation of buildings have enormous direct and indirect environmental consequences. Increased economy and population will create more and more challenges for the design, construction and operational community to fulfil the new requirements for infrastructure that are affordable, safe, resilient and sustainable while reducing their environmental impact. The building envelope's key feature is to offer shelter, safety, solar and thermal control, control of moisture, control of indoor air quality, access to sunshine, and outdoor views, fire resistance, acoustics, cost-effectiveness, and aesthetics. This study seeks to promote awareness on the energy friendly design strategies which economically minimize operational expenditure, while enhancing comfort of the occupants in the building. This work would allow architects, engineers and builders to choose the most efficient or climate-reactive envelope alternative in order to improve thermal environment efficiency of the construction design being proposed.
Impact of Heat Exchange on Building Envelope in the Hot Climates
The building envelope consists of both opaque and transparent parts of the walls and roof which in addition to the floor – are connected to the external environment. These may be single or multi layer, and represent the partition between the external and internal environment. The functions of the envelope include structural, aesthetical, environmental and other tasks. The environmental function is the primary one that protects the inner environment of the building from the impact of external variations of climatic phenomena.The building envelope is subjected to climatic influences by its individual orientation and composition. The main function of the building envelope in hot climates is to minimise external heat stress. Indoor thermal control can only be achieved through understanding of the thermal performance of the building envelope in relation to relevant weather parameters. It is also becoming increasingly realised that much can be done to mitigate heat stress in unconditioned buildings and to reduce cooling and heating loads and the energy consumption of air conditioned buildings, through a proper choice of building envelope materials and envelope design. The envelope’s response to climatic conditions is a major determinant of the amount of energy required to maintain the building’s thermal environment. Also, he building envelope directly influences the cooling peaks and air conditioning system capacity requirements.The thermal properties of the envelope are determined by the combination of wall mass, thermal resistance; insulation location, external surface colour, texture, and size. This study concentrates on the building envelope role in heat exchange and its characteristics and energy conservation In hot climates .
Thermal Insulation of Building Envelope Toward Zero Energy Design in Hot-Humid Climate
bounceinteractive.com
The use of thermal insulation in the building envelope in hot and humid climate is investigated through computer simulation. A total of 1,944 parametric simulation runs were carried out for three different cities and climate zones in Brazil (Curitiba, Brasilia and Salvador), considering variation of window-to-wall ratio, SHGC of the glazing system, insulation thickness in exterior walls, type of walls, and internal load densities. The results have confirmed that the building envelope has more influence on cooling energy consumption for building models with low interior load densities. Thermal insulation of exterior walls has negative impact for Brazilian cold climate, increasing the energy consumption for cooling as avoid the internal heat dissipation to the exterior environment. But in hot climate the energy consumption for cooling can be decreased with thermal insulation of exterior walls. In this case, the energy savings for cooling achieved up to 3.3%. Thermal insulation of exterior walls revealed to be a good solution to reduce peak cooling loads for the three climates under analysis, with 7.8% of maximum cooling capacity saving for the hottest city.
Thermal Performance of Innovative Building Envelope Systems in Mediterranean Climate
2017
Energy efficient buildings, besides saving energy, should provide adequate indoor thermal comfort. Hence, to maximize advantages, a balance between different energy efficient technologies and solutions must be found. In this sense, the European directives on the energy performance of buildings have defined a high standard of thermal insulation for buildings in order to comply with strict energy performance limits. However, several studies have highlighted that such an approach can have negative effects in summer, especially in the Mediterranean area, thus inducing an increase in the energy needs for cooling and a remarkable overheating. In this context, the main objective of this study is to investigate the thermal performance of Vacuum Insulation Panels (VIPs) and Phase Change Materials (PCMs) when applied to the building envelope, and their ability to improve the building thermal behavior in the Mediterranean area. To this aim, a numerical model of a test room with standard constr...
2018
Building envelopes function as an environmental filter; they form a skin around the building and control the influence of the outdoor environment. In hot arid climate, due to problems such as overheating and high solar gain, intelligent design strategies and technologies for building envelope are necessary. Since more than one third of energy use is consumed in buildings, more than by industry or transport, and the absolute figure is rising fast as the construction booms, especially in countries like UAE. Tall Office buildings need more attention due to their large size, energy consumption for cooling and lighting, and highly glazed facades. The study aims to optimize the envelope for office building in hot arid climate, in order to achieve thermal and visual comfort, energy efficiency, and make use of renewable energy. The study analysed the outdoor and indoor climatic conditions, taking different case studies to understand the problems of overheating, discomfort, and the energy needed to achieve indoor environment quality. The effects of applying different technologies and design strategies using computer simulation programs (Ecotect and Trnsys) on the comfort and energy efficiency were evaluated. The evaluations of technologies included: glazing performance, shading and solar control, insulation and thermal mass, and P.V integrated facades, as well as design strategies included: opaque transparent ratio, orientation, and natural day and night ventilation. The results showed a significant decrease in cooling loads and energy for lighting, and increase in thermal and visual comforts. These design strategies and technologies are suitable for architects and buildings facades engineers to be aware of the environmental performance of building facades and sustainable design, which adapt to the climatic conditions.
Sustainability, 2019
Expectations of traditional and contemporary buildings are different in terms of thermal comfort. Traditional buildings mostly achieve comfort through passive means, without HVAC support, but old levels of thermal satisfaction do not meet today's expectations, although their passive thermal performances are notable for contemporary building designs. In this regard, the current study tries to investigate the possibility of comparing traditional and contemporary buildings' construction techniques to achieve thermal comfort from an architectural point of view. In other words, is it possible to achieve passive building design by considering vernacular architecture principals as a reference? Likewise, how well can architects define insulation layers in contemporary construction surfaces in hot and humid climates? To this end, a dynamic, numerical, thermal calculation case study has been modeled in Famagusta, Northern Cyprus, to answer the above-mentioned questions. A mixed-use mode benefitting free-run periods is proposed and compared with a mode providing 24 hours of airconditioning in different scenarios using the same initial settings. Thus, different floor-to-ceiling heights, insulation placements and indoor conditions have been tested separately in both winter and summer periods. The results show that thermal comfort can be achieved in free-run periods only during a limited percentage of the year. Furthermore, although increasing building heights may lead to a rise in the free-run periods, in contemporary buildings it increases the total energy usage of the buildings between 6% and 9% in the mixed mode. Therefore, vernacular architecture strategies are proper in their own context. However, this energy usage can still be controlled and optimized by such considerations as insulation material placement. In this regard, the best envelope properties for different building functions are proposed for application in hot and humid climates.
Performative building envelope design correlated to solar radiation and cooling energy consumption
Nucleation and Atmospheric Aerosols, 2017
Climate change as an ongoing anthropogenic environmental challenge is predominantly caused by an amplification in the amount of greenhouse gases (GHGs), notably carbon dioxide (CO2) in building sector. Global CO2 emissions are emitted from HVAC (Heating, Ventilation, and Air Conditioning) occupation to provide thermal comfort in building. In fact, the amount of energy used for cooling or heating building is implication of building envelope design. Building envelope acts as interface layer of heat transfer between outdoor environment and the interior of a building. It appears as wall, window, roof and external shading device. This paper examines performance of various design strategy on building envelope to limit solar radiation and reduce cooling loads in tropical climate. The design strategies are considering orientation, window to wall ratio, material properties, and external shading device. This research applied simulation method using Autodesk Ecotect to investigate simultaneously between variations of wall and window ratio, shading device composition and the implication to the amount of solar radiation, cooling energy consumption. Comparative analysis on the data will determine logical variation between opening and shading device composition and cooling energy consumption. Optimizing the building envelope design is crucial strategy for reducing CO2 emissions and long-term energy reduction in building sector. Simulation technology as feedback loop will lead to better performative building envelope.
In this paper we evaluate the thermal performance of a range of modern wall constructions used in the residential buildings of Tehran in order to find the most appropriate alternative to the traditional un-fired clay and brick materials, which are increasingly being replaced in favor of more slender wall constructions employing hollow clay, autoclaved aerated concrete or light expanded clay aggregate blocks. The importance of improving the building envelope through estimating the potential for energy saving due to the application of the most energy-efficient wall type is presented and the wall constructions currently erected in Tehran are introduced along with their dynamic and steady-state thermal properties. The application of a dynamic simulation tool is explained and the output of the thermal simulation model is compared with the dynamic thermal properties of the wall constructions to assess their performance in summer and in winter. Finally, the best and worst wall type in terms of their cyclic thermal performance and their ability to moderate outdoor conditions is identified through comparison of the predicted indoor temperature and a target comfort temperature.
Innovation façade for an energy performance and thermal comfort of building in hot and dry climate
Journal of Fundamental and Applied Sciences, 2020
This paper discusses the energy innovation of external facade for existing residential buildings. It consists to taking into account both architectural and thermal aspects for new and old construction. With the use of energy wall systems, it is possible to reduce the heating/cooling demand of energy consumption and evaluate the indicators of energy performance. In doing so, this work can contribute not only to long-term economic growth, but also help address pressing social, including on a wide range impact environmental. We use a dynamic simulation with a structural equation modelling to test the hypothese on a data base of climate of this region. The final part consists technico-economic approach, calculating the investment costs analysis, comfort and energy saving. The results demonstrate its utility in explaining, regarding high systems availables in innovation performance.