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In thermodynamics, the heat transfer coefficient or film coefficient, or film effectiveness, is the proportionality constant between the heat flux and the thermodynamic driving force for the flow of heat (i.e., the temperature difference, ΔT ). It is used in calculating the heat transfer, typically by convection or phase transition between a ...
Thermal transmittance. Thermal transmittance is the rate of transfer of heat through matter. The thermal transmittance of a material (such as insulation or concrete) or an assembly (such as a wall or window) is expressed as a U-value. The thermal insulance of a structure is the reciprocal of its thermal transmittance.
Pearl Rating System (Abu Dhabi) The Pearl Rating System is the green building rating system developed by the Abu Dhabi Urban Planning Council as part of their sustainable development initiative, Estidama. The system can be applied to communities, buildings and villas, with different requirements for each. [1]
Estidama is a building design methodology for constructing and operating buildings and communities more sustainably. The program is a key aspect of the "Abu Dhabi Vision 2030" drive to build the Abu Dhabi emirate according to innovative green standards. "Estidama" is the Arabic word for sustainability. [1] The program is not itself a green ...
Window insulation reduces heat transfer from one side of a window to the other. The U-value is used to refer to the amount of heat that can pass through a window, called thermal transmittance, with a lower score being better. [1] The U-factor of a window can often be found on the rating label of the window. Although the concept of U-value (or U ...
Thermal conductivity and resistivity. The thermal conductivity of a material is a measure of its ability to conduct heat. It is commonly denoted by , , or and is measured in W·m −1 ·K −1. Heat transfer occurs at a lower rate in materials of low thermal conductivity than in materials of high thermal conductivity.
The R-value (in K ⋅ m 2/ W) is a measure of how well a two-dimensional barrier, such as a layer of insulation, a window or a complete wall or ceiling, resists the conductive [2] flow of heat, in the context of construction. [3] R-value is the temperature difference per unit of heat flux needed to sustain one unit of heat flux between the ...
Heating degree day. Heating degree day (HDD) is a measurement designed to quantify the demand for energy needed to heat a building. HDD is derived from measurements of outside air temperature. The heating requirements for a given building at a specific location are considered to be directly proportional to the number of HDD at that location.