EVALUATION OF ANNUAL PERFORMANCE OF MULTI-TYPE AIR-CONDITIONERS FOR BUILDINGS (COMPARISON OF EHP AND GHP)

In this paper, the results are presented on the partial thermal load performance tests of multi-type air-conditioners for buildings. We tested two types of air-conditioners, heat pump driven by electric motors (EHP) and that driven by gas engines (GHP), with a rated cooling capacity of 56 kW. The coefficient of performance (COP) and the annual energy consumption measured by those tests were closely compared with those predicted by JIS. In EHP, the measured COP attains the maximum under the indoor thermal load ratio of 50 %, while COP in GHP decreases gradually as the thermal load ratio is decreased. Based on these results, we examined the accuracies of COP and the annual energy consumption predicted by JIS. We found that in both EHP and GHP the current calculating method prescribed in JIS could not reproduce the deteriorations of COP that appeared under the low thermal load conditions. As a result, the annual energy consumption is seriously underestimated by JIS.