Air to water heat pump
EVI technology
Low working temperature
Higher COP in cold environment
Lower running cost and invest

Super Heating Performance at Low Ambient Temperature
 
Standard heat pump delivers best performance at 7°C ambient. Its efficiency drops significantly when the ambient temperature goes below 0°C, and when the ambient temperature goes below -5°C the heat pump generally will stop operation.

DC inverter heat pump though has an enhanced heating ability at low ambient generated from a bigger output of compressor, its limited ambient temperature is only down to -10°C.

EVI heat pump however has a super heating performance at even -15°C, which is realized through extra suction of compressor to increase the operating refrigerant.
 
Save your running costs further.