... air to water heat pump :AW10/L,AW13/LNormal air to water heat pump can work at above -10 ... degrees ,Low temperature air to water heat pump can work at -20 degrees.AW09,AW09B,AW12,AW12B, ... pumpON LINE SYSTEM is optionalDaily hot water pump: Wilo water pump is optionalElectric heater: 3KW ,6KW,9KW ... flow accurately, SCHNEIDER electronic parts make the unit work safely ,etc ;If you have any requirements, ...