Solar Water Heaters Home / Products / Solar Water Heaters Compact Thermosiphon Solar Water Heating System This non-pressurized solar water heater uses the principle of thermosiphon to collect heat from the sun and transfer it to hot water for residential and commercial uses. Horizontal Glass Evacuated Tubes Solar Collector This product is suitable for thermosiphon systems with higher level supplying cold water tank, and it is suitable for forced systems (direct or indirect pressurized or non-pressurized systems). Vertical Glass Evacuated Tubes Solar Collector This collector is suitable for thermosiphon systems with higher level supplying cold water tank, and it is suitable for forced systems (direct or indirect pressurized or non-pressurized systems).