Humidity Effects in Mobile Air-Conditioning Systems

Abstract

A humidity addition system was installed in the mobile air-conditioning test facility. The system is able to produce relative humidities at the evaporator inlet in excess of 95% RH. The system is able to control the humidity to with ± 2% RH of a setpoint. Regulation of the flow rate of water sprayed into the air provides the necessary humidity control. An analysis is developed to predict the ratio of latent heat transfer to total heat transfer from the air flowing over the evaporator. A large number of tests were conducted in the test facility to determine the actual latent heat transfer ratio. The latent heat transfer ratios predicted by the analysis are consistently lower than those measured in the test facility. A discussion of causes of the discrepancy is included in this paper.