... Air Source heat pumpModel: AW09,AW09B,AW10,AW10B,AW12,AW12B,AW13,AW13B,AW15,AW15B,AW20,AW20BLow temperature air to water heat pump :AW10/L,AW13/LNormal air to water heat pump ... : EmersonInternal differential pressure switchSoft starter 1 phase heat pumpON LINE SYSTEM is optionalDaily hot water pump: Wilo water pump is optionalElectric heater: 3KW ,6KW,9KW is ...