... .CE,ISO9001,CCC,certificates 4.for hotels,schools, offer OEM project solar collector size: 47mm,1500mm,/58mm,1800mm, tube quantity according the tank ... ,make a full system completely autumatic, you can uae hot water anytime, high efficient,and no-pollution.3. installation: instal full ... pipe for transfer hot, more high efficient, and water more clear,because no water in tube so can work in bad weather ...