Design Optimization of Passively Cooled Room

We consider this paper an actual design implementation of a passively cooled room, employing the night-cooling roof-pond method. The main intended application in our case is of cool storage of agricultural products in the region of Northern Thailand. As there have been no roof-pond systems specifically designed for the storage of agricultural products in a tropical climate, a fresh analysis of the system's thermal behavior leading to design changes should be made. Towards our application, this results in system optimization of two major design aspects: (1) The optimization of pond-water depth to achieve the target equilibrium temperature; and (2) the optimization of cool-room dimensions for best cost performance of the required volume of interior storage space. The paper begins by providing the general background and discussing the previous related works of passive cooling. Our main engineering analysis and mathematical modeling then follow. Equal emphasis is given to the solution methods as well as the detailed derivations of various model parameters. Sets of sample calculations are included as illustrations for the eventual application, with its final decisions based very closely on this study.