Abstract
We made the partial load performance tests of recently developed GHP VRF systems with rated cooling and heating capacities of 45kW and 50kW, respectively. COPs were measured at 37 test points for cooling operation and 31 test points for heating operation to make clear their detailed partial load performances. Based on the measured COPs and thermal load models for detached shops, the annual energy consumptions of these air conditioners were evaluated. They were compared with those obtained with conventional GHP VRF systems, and their energy-saving performances were demonstrated. Next, we applied a new calculation method of the annual energy consumptions of air conditioners, which was originally developed for EHP VRF systems, to the present GHP VRF systems. The variations of COP to the outdoor air temperature and the indoor thermal load were predicted based on COPs measured at 8 test points in the partial load performance tests. The annual energy consumptions of the tested VRF systems were calculated based on those predicted COP characteristics. It was confirmed that the errors included in the annual energy consumptions and resulting annual average COPs predicted by the proposed method were less than 7%.
