Performance and energy analysis of a solar hybrid desiccant air-conditioning system

This paper presents the performance of a solar hybrid desiccant air-conditioning system that was tested in a humid and hot weather of Malaysia. The system is consisted of a desiccant wheel, a solar thermal collector, a vapour compression refrigeration cycle and a heat pipes heat exchanger. In this system, the latent heat load of supply air was removed by a silica-gel desiccant wheel which was regenerated by a 31.5 m² evacuated tube solar collector assisted by an auxiliary heater. The sensible heat load was removed by pre-cooled the supply air using vertical heat pipes (act as a heat recovery system) before the air temperature is further reduced by a cooling coil connected to a conventional vapour compression cycle. Through the test, the supply and exhaust (regeneration) mass flow rate of air were maintained at 450 m³/hr. The Coefficient of Performance (COP), effectiveness of desiccant wheel and heat pipe were 1.42, 0.61 and 0.54, respectively. Reduction in energy consumption was estimated at 62% relative to a system without a desiccant wheel and heat pipe heat exchanger. It can be concluded that this system can provide supply air at a temperature of 23.4 °C and specific humidity of 0.011 (kg/kg) with a significantly less energy consumption in a hot and humid weather of Malaysia.