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.

Heat exchanger to exchange the heat between the hot solar panel antifreeze and the clean potable water. A typical closed loop solar water heating system consists of. There are two main types of solar hot water systems. A closed loop often referred to as a glycol or anti freeze system a drainback system.

Closed loop systems use a heat transfer fluid to collect heat and a heat exchanger to transfer the heat to household water. The type of system affects overall system design and each type of system has strengths and weaknesses. A special water heater tank incorporating a heat exchanger works in conjunction with one or more flat plate roof mounted collectors. Fluid expansion tank and safety relief valve.

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. Most new solar homes feature a variation of one kind or another. Sized for family load. Glycol or some equivalent antifreeze fluid fills the collector and associated routing pipes.

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.