We recently completed our latest solar hot water installation in Duluth Ga. The system is an EnerWorks type. These systems use a standard water heater as the solar storage tank. The EnerWorks “appliance” mounts to the storage tank and performs the heat exchange and pumping. The controller is also housed within the appliance.
The solar tank is piped in series with the existing water heater so the solar tank “pre-heats” the water coming into the existing tank. This is known as a pre-heat system.
System shown with panel cover removed. Note the heat exchanger, pump and small expansion tank. A supplemental expansion tank (gray tank against wall) was added to the solar loop for added protection against stagnation.
The two collectors are also from EnerWorks. They are 4′ x 8′ glazed flat-plate collectors which do an excellent job of collecting btu’s in southern climates. They are mounted on two C-channels which are secured to the roof with lag bolts. They are connected to the solar tank via 3/8” insulated copper tubing. This solar loop is filled with a 40% mixture of polyethylene glycol and distilled water and is circulated by the pump at the appliance.
The fluid is circulated through the heat exchanger and it’s heat is transferred to the potable water in the solar storage tank. This closed-loop system ensures no glycol enters the potable water, however the glycol is also non-toxic as required by code.