All water heaters waste heat energy even when the burner is off and the unit is sitting idle between heating cycles.
Closed loop solar water heater system.
Propylene glycol and the new bio green are common antifreeze materials we have several options for exchanging the heat to the clean domestic hot water.
The direct open loop solar water system freeze recirculation is both the simplest and most efficient type of solar heating system.
Heat exchangers in the storage tank eliminate a pump but make eventual tank replacement more.
Lots on installation detail.
Instead of relying on glycol for freeze protection this system allows all the water in the array to drain back from the array and into a storage vessel in the solar loop when the pump is turned off.
Most new solar homes feature a variation of one kind or another.
Closed systems are often used in second homes or primary residences in areas prone to long power outages.
Covers closed loop antifreeze systems and drainback systems.
In this system potable water is drawn directly from the storage tank and circulated through the array to be heated and returned to a recirculation port in the tank.
Hydronic heating systems must be filled with water to provide the heat transfer fluid htf that makes them work.
Very good articles on selecting the components for a closed loop solar hot water heating system suitable for cold climates.
In the case of the closed loop solar heating system the htf is typically a mixture of water and propylene glycol.
The process of filling the plumbing system with this antifreeze while purging all the air out must be done systematically and in the right order.
Glycol or some equivalent antifreeze fluid fills.
Closed loop solar heating system.
Indirect solar water drainback systems are also a indirect design that use a heat exchanger to separate the collector loop from the potable water.
If freeze protection is an issue than a closed system with anti freeze is a good idea.
A special water heater tank incorporating a heat exchanger works in conjunction with one or more flat plate roof mounted collectors.
Closed loop active antifreeze systems are the most versatile and failsafe of all the solar supplemental water heating systems.
Installation basics for solar domestic water heating systems chuck marken and ken olsen.
Here s how a solar powered water heater works.
To protect the unit you must consider an open or closed water heater system.
The heated water then flows into the storage tank before it s channeled into the heat exchanger.
When the controller senses that the sun is shining and your tank needs a warm up it signals the pump to send water through the black collector panels.
An open water heater system is when water that increased its volume and pressure due to the heating freely goes from the storage tank into the cold water supply line and eventually into the municipal water system if the pressure is high enough.