... balcony or windowsAdvantages:1.CE,UL,ISO9001,CCC,Solar water heater with SOLAR KEY MARK certificate2.High efficiency, Absorption rate: ... Endless hot water and no need waiting. Compare Solar to Conventional Water Heater SOLAR WATER HEATER: FREE energy from the SunSTANDARD WATER HEATER:COSTLY gas ... there are more than 800,000,000 Solar Water Heater units installed all over the world and because ...