... , and air-conditioning system commonly use heat pipes for heat conduction. The principle behind heat pipe's operation is actually ... air pressure, by evacuating the heat pipe, we can achieve the same result. The heat pipes used in AP solar ... , thus greatly reducing heat transfer performance. All-glass Evacuated Solar Collector Tube with Heat Pipe (SOLAR WATER HEATER,ISO9001,SOLAR KEYMARK,CE,SRCC,EN12975 ...