... Heating:Outdoor air temp:20°C/15°C,water tank water temperature from15°C heating to 55°C;( ... energy regulation.High efficiency and energy savingUsing high-efficient compressor rotary or scroll and heat exchanger, small volume, ... and reliableUnit protection against freezing, compressor high-pressure compressor, high and low voltage protection, compressor overtemperature, compressors flow, power supply ...