Notes on Gree Amber Nordic GWH09YD-S6DBA1 Heat Pump

As part of an experiment to add domestic water heating capabilities to conventional mini-split ACs, I purchased an air-source heat pump Gree GWH09YD-S6DBA1 which has an inverter controlled compressor and an electronic expansion valve that allows it to work efficiently even down to -30℃ (-22℉). Model GWH09YD-S6DBA2A where GWH09YD is...