... -efficiency: Absorb free heat from the air, compared oil boilers, gas boilers, electronic boilers, it reduces operating costs by 65-80 ... ). Auto-defrosting9) Widly used: widly be used in swimming pool, SPA pool, Sauna pool and etc.10) ECO-friendly. GS,CE ... CERTIFICATE Loading SPA pool heat pump, spa pool heater, spa pool heat pump water heater