Abstract:
Building envelope inspections are carried out for two specific purposes: (1) quality control of new or retrofitted wall assemblies and (2) existing building condition assessment. The purpose of quality control of new construction is to verify that there are no hidden defects that could result in premature material deterioration. Quality control of new construction is the more difficult task: the thermographer does not have the luxury of visual symptoms of material deterioration or failure. The thermographer has to make assessments and recommendations based on available construction drawings and thermal imagery of assemblies that do not show any visible evidence of problems . This chapter describes heat loss through exterior walls and the next chapter is devoted to roofs. The primary difference is that a roof survey usually relies on the sun to heat entrapped moisture. Since the walls are often shielded from the sun, a temperature difference between the interior and exterior is necessary. This is generally requires heating or cooling the interior. Evaporative cooling can also identify entrapped moisture. Building inspections are usually qualitative.Keywords:
Building envelope
Envelope (radar)
Envelope (radar)
Building envelope
Building Design
Opacity
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Building envelope
Envelope (radar)
Building science
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Retrofitting the thermal insulation of pitched roofs, especially those equipped with an impermeable sheathing membrane, may cause problems by moisture accumula- tion in the roof. As a non-ventilated insulation makes use of the whole cavity between the rafters and can be realized much more easily it should be preferred over a ventilated con- struction if possible. However, this requires that the roof assembly can dry out to the inte- rior side, so that any moisture penetrating into the roof by accident will not be trapped permanently. The influence of the local climate, roof orientation and inclination as well as the interior conditions on the hygrothermal performance of an unventilated pitched roof has been determined by numerical investigations. The results show that a north ori- entation combined with a strong inclination is the least favourable situation for the drying potential of the roof. The application of a humidity-controlled vapour retarder offers the best solution against moisture related problems under all investigated conditions. How- ever, under favourable boundary conditions also a moderate vapour retarder provides a working alternative.
Retrofitting
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This book results from a Special Issue published in Energies, entitled "Building Thermal Envelope". Its intent is to identify emerging research areas within the field of building thermal envelope solutions and contribute to the increased use of more energy-efficient solutions in new and refurbished buildings. Its contents are organized in the following sections: Building envelope materials and systems envisaging indoor comfort and energy efficiency; Building thermal and energy modelling and simulation; Lab test procedures and methods of field measurement to assess the performance of materials and building solutions; Smart materials and renewable energy in building envelope; Adaptive and intelligent building envelope; and Integrated building envelope technologies for high performance buildings and cities.
Building envelope
Envelope (radar)
Building science
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The purpose of this analysis is to determine "typical" building envelope characteristics for buildings built after 1980. We address three envelope components in this paper - roofs, walls, and window area. These typical building envelope characteristics were used in the development of DOE's Reference Buildings .
Envelope (radar)
Building envelope
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According to the climate characteristics in Chongqing,the paper focus on the relationship between building energy consumption and envelope. Through analysis on the current situation of building envelope,to improve building envelope thermal performace and make indoor thermal more comfortable as well as reduce energy consumption,it put forward some points for insulation control in this region,and discussed several key steps of envelope energy efficiency.
Building envelope
Envelope (radar)
Consumption
Dynamic insulation
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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 minimize 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 realized 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.
Building envelope
Envelope (radar)
Dynamic insulation
Building Design
Thermal mass
Passive cooling
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The building envelope plays an important role for the contributions to the whole building thermal load, especially for residential houses without significant internal heat gain; hence, it is a critical component for influencing a building's thermal performance. However, the envelope R-value is usually acquired from the original design value, regardless of the thermal insulation degrading that has occurred during the whole long lifecycle. The main reason lies in that, with traditional methods, the in situ envelope R-value is extremely inconvenient to measure. In this study, a simple noninvasive approach was proposed to measure the envelope R-value using the interfacial thermal resistance from the thermal boundary layer between the envelope exterior surface and the ambient air, and the envelope surface temperature measured through the infrared thermal imaging. A field measurement procedure was developed and implemented for a typical detached residential house, along with a widely accepted method using film heat-flux sensors as a validation test. The final results show a good approximation between these two tests, which shows that the proposed method could extend the functions of thermography from only qualitative diagnosis to quantitative measurement on envelope thermal performance.
Building envelope
Envelope (radar)
Thermography
Thermal mass
Thermal transmittance
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The building envelope plays a crucial role in saving or consuming energy, depending on the type of the envelope and design. Architects and engineers need to consider many issues when working with envelope designs, including environmental issues, aesthetic appearance, occupant comfort, and view; these aspects make the envelope a multifunctional component, thus the integration approach is the optimal method to address envelope design. In the last decade we have witnessed the inclusion of the kinetic envelope in many typologies of buildings. Many scholars believe the kinetic envelope improves the environmental performance of the building. The purpose of this paper is to review the current practice and development of the kinetic envelope and to investigate its role in the improvement of energy performance in buildings.
Building envelope
Envelope (radar)
Component (thermodynamics)
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