... .Wkg125160280560650760High-efficiency:1) Famous America Copeland Compressor;2) America shell & tube high efficiency heat exchanger;3) Environment-friendly refrigerant R22 ... ;6) Saving cost as high as 60%~80% compared with oil boiler, gas boiler,coal boiler, electricity water heater ... , factory, school, hospital, military, villa,village etc. Commercial Series Air Source Heat Pump (Circulation heating)