... .Adopts world famous parts 3.On line system 4.R410a Air Source heat pumpModel: AW09,AW09B,AW10,AW10B,AW12,AW12B,AW13 ... heat pump can work at above -10 degrees ,Low temperature air to water heat pump can work at -20 degrees.AW09 ... (20% than than double pipes or other types ) , repair easily;Air exchanger (Fan coil ) with hydrophilic coating ,higher coefficient of heat ...