Closed Loop System Solar Water Heater

A closed loop often referred to as a glycol or anti freeze system a drainback system.

Closed loop system solar water heater.

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. The type of system affects overall system design and each type of system has strengths and weaknesses. 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. Closed loop active antifreeze systems are the most versatile and failsafe of all the solar supplemental water heating systems.

Solar controller to automatically control the pumps. Glycol or some equivalent antifreeze fluid fills the collector and associated routing pipes. Most new solar homes feature a variation of one kind or another. Fluid expansion tank and safety relief valve.

A typical closed loop solar water heating system consists of. Closed loop systems use a heat transfer fluid to collect heat and a heat exchanger to transfer the heat to household water. 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. Heat exchanger to exchange the heat between the hot solar panel antifreeze and the clean potable water.

There are two main types of solar hot water systems.