Abstract
The authors proposed a passive cooling method in our previous paper, i. e. to induce cooled air in a crawl space to an indoor space by ventilation. This method was examined by model house tests without direct solar heat gain. In this paper, this method is re-examined under various conditions and its thermal performance is simulated for practical use. The experiment models used here are houses without windows, with windows and with windows fixed with eaves. The cooling effect of this method is recognized in all these cases. Thermal performance in a crawl space, the mechanism of this cooling method, is modelled for numerical simulation. The calculated air temperature in the crawl space and that in the room are in good accordance with those of model house tests. This numerical simulation model is applied to the estimate of three factors which influence the cooling power of the crawl space. They are the length of the crawl space, the ventilation rate and the evaporation ratio. It is also applied to the simulation of the thermal performance in the practical scaled model houses. They are wooden, reinforced concrete and wooden double envelope house. The practicability of this passive cooling method is made clear by the numerical simulation.
