Air-to-Water Heat Pump PLR performance curve issue
I have a model using E+ 22.2.0 which consist of one air-to water heat pump for heating and cooling of a small office building in a cold climate. The model uses the HeatPump:PlantLoop:EIR:Heating and HeatPump:PlantLoop:EIR:Cooling object.
When running the model with the CAP_FT factor and the EIR_FT factor, the output COP of the heat pump are the one expected from the performance table. However, I am having an issue when I add the EIR_FPLR factor. I am using a performance table to provide the EIR_FPLR factor with the data provided from an example using the data below. However, when adding such performance table in the model, the COP increases to very high values (9 to 20) especially in cooling mode. From my understanding, this is due to the low PLR operation and thus low EIR_FPLR factor which results in a low electricity consumption from the Heat Pump (Power output = PrefEIR_FTEIR_FPLR). Does anyone have faced similar issues when using the EIR_FPLR for air to water heat pump? Also Is there any recommended performance curve suitable in cold climate for an air-to-water heat pump in E+?
PLR performance Table:
PLR input [0, 0.25, 0.5, 0.75, 1]
HP_EIRFPLR output [0, 0.296357, 0.399506, 0.648768, 1]
Thank you