Abstract
On the passive solar system that was composed of transparent wall, the cooling effect that was acquired by creating water film on the exterior surfaces was measured and verified by prediction formula in consideration of interreflection. On the experiment, the greenhouse with water film that consisted of transparent wall with the super-hydrophilic photocatalyst and the one without water film were built, the cooling effect was confirmed by comparison between various data on two experiment models. Moreover the prediction value was calculated by prediction formula that was taken interreflection into consideration and arranged the conservation equation of greenhouse energy and the heat balance equation on the exterior wall surfaces that were reported by the present. The result can be summarized as follows: Comparison of the experimental data with the prediction data that was calculated by the arranged prediction formula and some constants that were obtained through the experiments under the various weather conditions indicated good agreement. (i) The evaporation cooling effect of creating water film on the exterior wall surface with the super-hydrophilic photocatalyst was determined quantitatively. (ii) Measurements showed that the coefficient of heat transfer could be set as one constant. Therefore heat balance equation could be calculated, the exterior surface temperature and the amount of evaporation could be predicted easily. (iii) The experimental result has demonstrated that the latent heat of water film on the exterior wall surfaces occupied from 18 to 32% heat radiation of experimental model at daytime.
