Conventionally in building performance simulations (BPS), it is assumed that air entering outdoor HVAC equipment is at the outdoor ‘ambient’ temperature, obtained from a weather file. However, significant spatial variations exist in outdoor air temperature fields, especially within the thermal boundary layers that form near exposed surfaces like roofs.

Cool roof technology is known to reduce the cooling energy consumption of conditioned buildings during hot periods, and widespread implementation of such roofs in a neighbourhood or precinct can mitigate the urban heat island effect. Established building energy modelling techniques are able in principle to predict the benefits of cool roofs due to reduced heat...