... heater systemWorking principle:when the diffeference of collector temperature and tank temperature gets to the set value, the circulation system ... tube, borrosilicate glass 3.37) Solar working station8) With heat pipe: anti-freezing > -35 degrees centigrade9) Water capacity: 150L, ... Alloy,Thickness,1.8mm,Insulating layer,compressed rock woolHeat Pipe pure red copper TU1+water,transfer power>=150W, ...