PERFORMANCE CHARACTERISTICS OF A SIMULTANEOUS HEATING AND COOLING HEAT PUMP IN THE HEAT RECOVERY MODE

Abstract

The cooling load in winter is significant in buildings and hotels because of the usage of office equipments and the high efficiency of wall insulation. Hence, the development of a multi-heat pump that can cover heating and cooling simultaneously for each indoor unit is required. In this study, the performance of a simultaneous heating and cooling heat pump was investigated in the heat recovery mode (HR mode). The system adopted a variable speed compressor using R-410A with four indoor units and one outdoor unit. In the HR mode, the capacity and COP were improved as compared with those in the cooling or heating mode because the waste heat in the outdoor unit was utilized as useful heat in the indoor units. However, energy imbalance between heating and cooling capacities of each indoor unit was observed in the 2H–1C HR mode. Therefore, the performance of the system in the 2H–1C HR mode was enhanced by controlling refrigerant flow rate through the outdoor unit.