... above -10 degrees ,Low temperature air to water heat pump can work at -20 degrees.AW09,AW09B,AW12,AW12B, ... phase heat pumpON LINE SYSTEM is optionalDaily hot water pump: Wilo water pump is optionalElectric heater: 3KW ,6KW,9KW is ... humanized display ,alarm automatically , heating system equipments can be controlled;EMERSONE expansion valve control the refrigerant flow accurately, SCHNEIDER electronic ...