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 transfer through the roof structure. However, several scientific and industry publications have claimed that additional benefits can arise from the reduction in air temperature above cool roofs. Rooftop heating, ventilation and airconditioning (HVAC) equipment energy consumption would be reduced by such an effect, and the efficiency of rooftop photovoltaic (PV) panels would be improved.
A small number of studies have attempted to quantify the effects of cool roofs on above-roof temperature fields and the performance of rooftop equipment, but these studies have been relatively small in scope and have produced varying results. It is likely that some such effects exist, that are not currently taken into account in assessments of roof performance, but prior to the present project it was not possible to determine whether such effects are significant. This report summarises the work carried out under project RP1037, the aim of which was to generate experimental evidence, and other data, that may be used to more accurately quantify the benefit of cool roofs to Australian largefootprint buildings, including the generally unaccounted-for above-roof effects described above.