Center for the Built Environment

Cooling energy savings and improved thermal comfort in hot climates can be achieved using cool roofing materials. High solar reflectance and infrared emittance values reduce the amount of absorbed solar radiation and the surface temperature of a material exposed to sun radiation, consequently the heat transfer into the building is lowered. A reduction of the urban heat island effect, caused by the presence of high absorption surfaces and the lack of vegetation, may be obtained using cool roofing materials.

Computer energy simulations have been used to assess the energy savings and temperature profiles consequent to the application of a cool roofing material when applied to industrial premises in three Mediterranean cities: Genoa, Madrid and Cairo. In particular, the related influence on cooling energy demand and maximum temperature at the outside face of the roof are analyzed, varying the roofing material and the insulation thickness.

The results of this study showed that using a cool roofing material in the Mediterranean area for industrial premises leads to significant sensible cooling energy savings, up to 42%. Moreover, it was obtained that the maximum roof outside surface temperatures decrease of 40÷50°C when cool roofing materials are applied.