27 tube solar water heater all-glass evacuated tubular collector design with sealed all glass heat pipes.  170 liter stainless steel inner tank,  aluminum stand, air vent, water inlet and outlet fittings, tank cover, foot cushions, end caps and automatic filler valve mechanism  are all included. 

Vacuum tubes can never freeze, since they contain no water.  Optional auxiliary electric heater and controller can keep water temperature constant. Manual filling and draining possible, or connect directly to pressurized water with auto-filler valve to keep tank full.

-Low pressure system, vented to atmosphere, gravity drain.

-Similar appearance to pressure model without reflector.

-Gravity drain most common in China

Package contains a complete solar water heater:

·  Stand alone system, no additional parts

·  Economic system for typical house

·  No electricity or pumps required.

·  Assemble yourself in 3 hours

·  Optional electronic controller-heater

·  Graded Al-N/Al selective coating, high energy absorption and low heat transfer losses

·  highly evacuated with pressure ≤5×10^-2 Pa in the space between outer and inner covers, so no heat loss

·  All Glass Heat pipes transfer heat energy in one direction only

·  High transparency with boron silicon glass, high resistance to cold water shock