Solar sorption cooling for residential air-conditioning applications

This paper presents the comparison of two sorption cooling systems for providing air conditioning in a residential building that can be driven by a flat plate solar collector. A thermodynamic model has been developed for each system to compare the energy balance in each component and the coefficient of performance (COP). Analyses have been performed for 10 kW water-ammonia absorption and activated carbon-ammonia adsorption chillers. For both systems, the first law efficiencies have been compared and the optimum efficiency has been investigated under different operating conditions. Analysis revealed that under any operating condition, the COP is always higher for the absorption chiller and its maximum value is 0.6, which is almost twice that of the adsorption chiller (COP = 0.35), for 10 kW systems operating at evaporator and condenser/absorber temperatures of 2°C and 30°C, respectively. The adsorption system requires a higher energy input to produce the same cooling effect as compared to the absorption system.