Performance characteristics of a combined air conditioner and refrigerator system interconnected via an intercooler

• Heat pump and refrigerator are inter-connected using an intercooler.
• Experimental investigation on performance of this combined system.
• Electric power consumption of this combined system was reduced by 32%.

Convenience stores and supermarkets are equipped with air conditioner and refrigeration/freezer systems that are independently operated; these systems consume approximately 50%–60% of the total electric power used by the convenience store or supermarket. In this study, a combined system that can recover the condensation heat of the refrigeration system into the air conditioner using an intercooler is developed. Experimental investigations are conducted in order to investigate the performance characteristics of the combined system. Then, the proposed combined system is installed in a convenience store and operated for one year in order to measure the annual power consumption in a real environment. The proposed combined system exhibits an increase in the operation ratio, a reduction in defrosting operations, and a 32% reduction in the annual electric power consumption. The intercooler contributes to the reduction in power consumption, as does the use of a variable speed compressor. It is also found that the flow rate of the intercooler should be optimized when the air conditioning system is operated in the cooling mode.