Development of high efficiency VRF systems under partial heat load for commercial buildings
VRF systems in commercial buildings are mostly operated under less than 50% heat load through a year, even if the capacity is optimally selected. Therefore it is important to improve its performance under low heat load condition. For this purpose, innovative energy saving A/C controller and compressor were developed in order to enable an optimum operation under low heat load conditions in buildings. These technologies were applied to new developed VRFs "VRV X" and these new VRF products have been launched since March, 2015 in Japan. The partial heat load performance tests of the conventional VRFs and new VRFs were conducted by air enthalpy method. This report shows the operation states and the EER/COP of the new VRFs in comparison with those of the conventional VRFs by the laboratory tests in the test facility. And the seasonal average EER/COP (not SEER/SCOP) of these VRFs was predicted by combining the EER/COP of the VRFs obtained by the laboratory tests and the annual variations of operating conditions in the model building.