Urban heat islands pose significant challenges as they intensify the impacts of climate change and compromise urban living conditions. White roofs, having a high albedo, are able to reflect solar radiation and reduce roof surface and near-surface air temperatures. However, there has been limited research on the effectiveness of white roofs in reducing conductive heat flux into buildings (G) and air conditioning (AC). To bridge this research gap, the Community Land Model Urban (CLMU), an improved numerical urban climate model that includes parameterizations of urban heat mitigation strategies, was employed to compare two scenarios for the contiguous United States (CONUS) from 1981 to 2000: one scenario using regular roofs and the other using white roofs. White roofs are found to demonstrate greater temperature reductions in hotter climate zones compared to cooler ones, with a similar trend observed for reductions in air conditioning demand. Surprisingly, AC is not found to be directly linked to G, indicating a more intricate relationship between changes in roof albedo and AC demand. The building energy balance is further investigated, aiming to elucidate the heat transfer mechanisms involved. The results emphasize that reductions in AC through the implementation of white roofs are contingent on specific conditions.