... tube, borrosilicate glass 3.37) Solar working station8) With heat pipe: anti-freezing > -35 degrees centigrade9) Water capacity: 150L, 200L, ... 80h13) Electric heater: 1.5Kw to 3Kw Solar collector(Heat pipe series)SC-H seriesModelSC-H-15-5818SC-H-18-5818SC-H ... Aluminum Alloy,Thickness,1.8mm,Insulating layer,compressed rock woolHeat Pipe pure red copper TU1+water,transfer power>=150W,Working pressure ...