Energy performance of cool roofs under the impact of actual weather data

The findings suggest that: (1) there is a deviation from 3% to 29% between the predicted energy performance under CWEC and that under actual weather data; (2) highest roof insulation level has the least overestimation in space conditioning energy demand; (3) cool roof with the least roof insulation level has the largest overestimation in space conditioning energy demand; and (4) the majority of cool roof designs estimated by CWEC tends to be overestimated which leads to more conservation designs. This paper demonstrates the importance to evaluate the long term performance of the cool roof by taking into account actual weather data. And it also quantifies the potential overestimation in energy demand and offers designers a reference at early design stage of cool roof in the cold climate