... and automatic operationc. Anti-freeze: Using the anti-freezing liquid as the medium and the controller hasthe anti-freezing functiond ... tube, borrosilicate glass 3.37) Solar working station8) With heat pipe: anti-freezing > -35 degrees centigrade9) Water capacity: 150L, 200L, ... Alloy,Thickness,1.8mm,Insulating layer,compressed rock woolHeat Pipe pure red copper TU1+water,transfer power>=150W,Working ...