These systems pump heat-transfer fluids (usually a glycol-water antifreeze mixture) through the solar water heater. Heat exchangers transfer the heat from the fluid to the water that is stored in tanks. Double-walled heat exchangers or twin coil solar tanks prevent contamination of household water. Some standards require double walls when the heat-transfer fluid is anything other than household water. Closed-loop glycol systems are popular in areas subject to extended subzero temperatures because they offer good freeze protection. However, glycol antifreeze systems are more expensive to purchase and install and the glycol must be checked each year and changed every few years, depending on glycol quality and system temperatures.

Advantage:

1.Simple Installation,No Maintenance,Effective operation

2.Easy Retrofitting To Existing systems

3.Suitable for single and multiple solar heating Application systems,

4.Preferred option for extremely cold areas and questionable water quality. I5.ncoming potable water is routed to the solar storage tank

6.Porcelain Enemal or SUS316 Stainless Stee Storage Tank With Electrical or gas Back Up

7.Double-walled Copper Coil heat exchangers in storage tank prevent contamination of household water.