Passive cooling application in a hot and humid country: Theory and experimentation. Case study: Khon Kaen, a city of northeastern Thailand.

摘要

The application and cooling efficiency of an indirect evaporative cooling system were studied, based on experiments at UCLA, in Los Angeles, USA. The experiments included in this research are: (1) Shower Tower and Conventional Heat Exchangers; (2) Shower Tower and Concrete Roof as a Heat Exchanger. The indirect evaporative cooling systems can reduce indoor air temperatures without introducing extra humidity into the interior space. Formulas were developed to predict the pond temperature from wet bulb temperature and vice versa, and to predict the maximum indoor air temperatures from average outdoor air temperatures. Climate data from Khon Kaen, Thailand, where my future university is located, were used as a case study to test the formulas in predicting the performance of the system in a hot and humid climate. The results from the prediction show that the cooling system would drop the maximum indoor air temperature of a test-cell from the maximum outdoor air temperature 1.12°C in Khon Kaen, as compared to be a 1.50°C in the test-cell at Los Angeles. The same cooling system with additional mass would cause a 2.52°C drop in Khon Kaen, compared to a 4.30°C drop in Los Angeles. When mass was combined with night ventilation, it would drop 4.42°C in Khon Kaen, and 7.60°C at Los Angeles. When the test-cell with mass was painted white (with out ventilation), the drops were 2.92°C in Khon Kaen, and 4.50°C at Los Angeles. However, since the experiments were conducted in a hot and dry location, and the prediction is extrapolated to a hot and humid place, an actual experiment in Thailand is planned to verify these results. The calculated data using the experimental predictive formula shows a good match with measured data. The application of this system to architectural design in the Khon Kaen climate was studied and design guidelines were recommended. An experimental plan for the actual experiment on indirect evaporative cooling system in Khon Kaen is proposed.