Analysis of surface temperatures and air-conditioning loads of buildings equipped with water-retentive building materials

We conducted an outdoor experiment and numerical analysis to clarify the mitigation effects on the surface temperatures and reduction of the air-conditioning loads of buildings equipped with water-retentive building materials. In the outdoor experiment using two housing units in the daytime during summer, the cooling effects of the water-retentive building material were demonstrated by decreases in the roof surface temperature by 20°C, and in the room air temperature by 1.2-1.7 °C. Next, a building heat load model was coupled with a simultaneous heat and mass transfer model to confirm whether simulation results were consistent with the observed data for surface temperature and room air temperature. We then implemented case studies using assumptions for standard buildings, and found that the use of water-retentive building material had a cooling load reduction effect of by 9.8-15.1% in the case of a factory and, 9.0-13.8% in the case of an office.