... :100-500L 2. Anti-freezen&Pressurized 3. CE, SRCC, Solar keymar Split Solar Energy Water Heater Features, Specifications, Size, Accessories 1) The tube ... all-glass evacuated tube and metal-glass evacuated tube with heat pipes 2) Suitable for frigid zones because there is no ... part is a vacuum glass tube that lowers heat loss 6) Stable solar conversion throughout the day, with the round shaped tube ...