Solar energy absorption by a building wall is affected by many parameters, including the structural characteristics of the wall, the heat-transfer coefficient of the south wall's outer surface, the radiation intensity and outdoor air temperature, etc.
Does external wall Solar absorptivity affect building energy use?
Although external walls present an important share of the building envelope and have a substantial contribution to the building energy use, the effect of the external wall solar absorptivity is less researched ( Pisello et al., 2017) in comparison to roofs, especially under temperate climate conditions.
Does Solar absorptivity affect building energy use and indoor thermal conditions?
Therefore, within this study, building energy use and indoor thermal conditions were analysed for an office cell using different types of solar absorptivity (e.g. white, dark grey, collector or cool coating) and thermal transmittance, on either external wall or roof. The analysis was conducted for hot-arid and temperate climate locations.
They stated that roofs and walls of buildings absorb most of the solar radiation received by urban areas, while the relatively small amount is absorbed by the ground, especially in highly dense urban areas.
Does Solar absorptivity affect thermal response of roof/wall?
Thermal response of roof/wall was analysed by altering U value and solar properties. Solar absorptivity has significant effect on total energy use, especially at U > 0.3. Optimal total energy use in Hamburg and Granada was always achieved by cool coating. Coating's solar properties affect indoor thermal comfort in summer and winter.
How does surface temperature affect external Solar absorptivity?
Surface temperature in reference to external solar absorptivity The influence of the external surface absorptivity reaches beyond the issues of energy performance, because it affects the indoor comfort through the internal surface temperatures of building envelope.
How to control solar properties of building external surfaces?
The solar characteristics of the building external surfaces can be controlled by the application of material having the desired optical properties, such as green vegetation surfaces, or by using spectrally modified coatings. The latter were developed in order to enable focused utilization of the coating optical characteristics.