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 system solar water heater.
Solar controller to automatically control the pumps.
The type of system affects overall system design and each type of system has strengths and weaknesses.
Sized for family load.
Closed loop systems use a heat transfer fluid to collect heat and a heat exchanger to transfer the heat to household water.
Fluid expansion tank and safety relief valve.
A typical closed loop solar water heating system consists of.
A special water heater tank incorporating a heat exchanger works in conjunction with one or more flat plate roof mounted collectors.
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.
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.
Most new solar homes feature a variation of one kind or another.
Closed loop active antifreeze systems are the most versatile and failsafe of all the solar supplemental water heating systems.
A closed loop often referred to as a glycol or anti freeze system a drainback system.