... ,reliable 4.R407c & R410a Refrigerant heat pump water heater High-efficiency: 1) our own advanced heat pump technology2 ... with oil boiler, gas boiler, coal boiler, electricity water heater etc. Environment-friendly: ODP---Ozone Depletion Potential, GWP--Global ... exchanger.3)no potential hazards of inflammable, explosive, electric shock,gas poisoning. Model KFRS-90IIheating capacitykw87.4water flow ...