Performance study of open pond as heat sink of water-cooled air conditioner

Abstract

In this paper, performance of open pond as heat sink of water-cooled condenser instead of cooling tower was considered. Experimental test of a 3.5 kW R32 air conditioner with 3m×3m×1.1 m open pond was performed and the unit was running between 8 a.m. and 6 p.m. on a clear sky day in summer of Chiang Mai, Thailand. A model to predict the average pond temperature and energy efficient ratio (EER) of the air conditioner was developed and the simulated results agreed well with those of the experiments. The model was used to find out the suitable pond volume that could keep the air conditioner EER over 4.1 when the number of air-conditioner were changed from 1 to 3 units on the hottest day in April. By adjusting the appropriate ratio of pond surface area and pond depth (A/D), the pond temperature on the next day could be lower or equal to that on the previous day then the air-conditioner EER should be at least similar to that on the previous day.