... heated by solar energy, while in cloudy or rainy days, the water is heated by air energy 2) Safe, high efficiency, ... air, only 1/4 electricity consumption of electrical water heater 2) Utilizing high efficiency, environment protecting working substance 3) World top ... defrosting system, totally solving making heat problems in winter About solar water heater: 1) Vacuum tube size: Φ58x1,800mm 2) Bracket: ...