Experimental Study of a House-Hold Dual Evaporation Temperatures Based Chiller

Indoor environment control strategies in small buildings are simply considered, such as achieving the indoor temperature control through ON/OFF cycling the compressor of a direct expansion (DX) air conditioning (A/C) system, leaving the indoor humidity uncontrolled. In some areas, the large latent cooling load will lead to an unstable and high indoor humidity, resulting in deteriorating thermal comfort, indoor air quality and energy efficiency, suggesting that an actively controlled humidity is indispensable. The existing temperature and humidity independent control (THIC) methods are too complicated to be suitable for applying in small buildings. Therefore, the authors established a water chiller which can be applied in residential buildings for THIC by using a dual-evaporation-temperature compressor. A prototype was built and experimentally tested. Results showed that in the varying summer condition, the high and low water supplying temperatures were maintained around 18.8°C and 7.8°C, respectively, suggesting that this novel chiller could provide chilled water of two different temperatures for THIC. Furthermore, the energy efficiency ratios (EER) of the compressor was 3.5, which was comparable to those conventional DX A/C systems or chillers of the same size. Therefore, this novel chiller based on dual evaporation temperatures was feasible.