Performance of a solar integrated heat pump air-conditioner, water heater and dryer

Abstract

In this study, a solar assisted heat-pump system for air-conditioning, water heating and drying was designed and constructed and the performance evaluated. The three applications can be served simultaneously or independently. The presence of an innovative two-phase unglazed solar evaporator-collector, where refrigerant R-134a was used as the fluid, enabled the system to operate round the clock. The evaporator-collector gained, instead of losing, a significant amount of energy from the ambient environment due to the low operating temperature of the collector. A large fraction of the energy requirement is met by a combination of energy collected from the sun, ambient and the energy recovered from a vapour compression heat-pump system, which also serves as an air-conditioner. One of the two condensers served as a water heater and the other for heating the air to the required temperature for drying purposes. A series of experiments were conducted under the meteoro-logical conditions of Singapore to evaluate the system performance under different applications and operating conditions. Maximum COP achieved during the experiment was about 6.8. This system could ensure long-term operation under different working conditions and reduce building heating costs, especially for hotels and hospitals in the tropics. © Ambient Press Limited 2008.