Study on evaporative cooling effect of roof lawn gardens

摘要

In a very hot climate equivalent to a Japanese summer, the reduction of heat coming into rooms in very important with respect to thermal comfort and energy efficiency. The objective of this study is to investigated the evaporative cooling effect from roof lawn gardens planted in non-woven fabric as one mode of passive cooling. It was confirmed by field measurements during the summer that the amount of heat coming into the rooms was reduced by a roof lawn garden. That is, the surface temperature of the roof slab decreased from about 60 to 30 deg. C during daytime, which was estimated to be followed by a 50/100 reduction in heat flux into the room by simple calculation.