heat pump water heater 1.High efficiency,safety,reliable 2.Automatic defrost 3.Safety,reliable 4.R407c & R410a Refrigerant heat pump water heaterHigh-efficiency ... %~80% compared with oil boiler, gas boiler, coal boiler, electricity water heater etc.Environment-friendly: ODP---Ozone Depletion Potential, GWP--Global Warming ...