Closed Loop System Solar Water Heater

Closed loop active antifreeze systems are the most versatile and failsafe of all the solar supplemental water heating systems.

Closed loop system solar water heater.

Most new solar homes feature a variation of one kind or another. Indirect closed loop solar glycol systems use propylene glycol as the heat transfer fluid in the solar array to overcome issues of freezing glycol can tolerate 60f in high concentrations and eliminate scaling. Sized for family load. Solar controller to automatically control the pumps.

The primary difference between the two system types is that water is used for heat transfer in a drainback system and a glycol solution is used for heat transfer in a closed loop system. Fluid expansion tank and safety relief valve. A typical closed loop solar water heating system consists of. The glycol is separated from the potable water by means of a heat exchanger that transfers the energy from the array into the storage tank.

Active closed loop systems use electric pumps valves and controllers to circulate the heat transfer fluid usually a polypropylene non toxic unlike polyethylene glycol water antifreeze mixture through the collectors. There are two main types of solar hot water systems. A special water heater tank incorporating a heat exchanger works in conjunction with one or more flat plate roof mounted collectors. Heat exchanger to exchange the heat between the hot solar panel antifreeze and the clean potable water.

The type of system affects overall system design and each type of system has strengths and weaknesses.