Evaporative Cooling Performance Resulting from Changes in Water Temperature

Abstract

Three trials were conducted to determine the effect of water temperature on the performance of an evaporative cooling system. A small, self-contained pad and fan evaporative cooling system with a 1.3 1.3 m (4 4 ft) cross-section tunnel and a 0.9 0.9 m (3 3 ft) area pad was used for the test. Inlet air temperatures were 32, 35, and 38C (90, 95, and 100F). Water temperatures were 10 to 50C (50 to 120F) in 5.5C (10F) increments. Results showed that for each inlet-air temperature tested, the performance of the evaporative cooling system worsened as the water temperature increased. Over the range of treatments, dry-bulb temperature and relative humidity of the conditioned air increased over 2.2C (4.0F) and over 3.2%, respectively; the amount of water evaporated increased 73%; and the system efficiency declined 16.1%. The results support the conclusion that as the water temperature increases, the performance of evaporative cooling systems decreases.