Closed Loop Hot Water Heater

A special water heater tank incorporating a heat exchanger works in conjunction with one or more flat plate roof mounted collectors.

Closed loop hot water heater.

These units are completely packaged systems designed for a maximum operating temperature. This is always the location of the heater drain valve. A closed water heater system means that the hot water cannot expand beyond the valves and mix with the municipal water. Glycol or some equivalent antifreeze fluid fills the collector and associated routing pipes.

If you have a dedicated return line then this is a great system to use. I added a return line from two locations through a check valve in. The water from the boiler to this heat exchanger flows 24 hours a day in a closed loop making the heat exchanger continuously active i e. Closed loop active antifreeze systems are the most versatile and failsafe of all the solar supplemental water heating systems.

Whenever needed the storage tank draws heat from the heat exchanger and maintains a constant tank temperature. Attach a wrench to the valve and turn counterclockwise. The km series of heat transfer systems is designed for closed loop temperature control of common heat transfer fluids. The advantages of a continuously active heat exchanger loop are twofold.

A hot water loop uses a small pump to circulate hot water between a water heater and a distant bathroom or kitchen. However doing so in a way that doesn t waste a lot of energy is a little trickier. This loop keeps hot water going throughout the house so when a fixture is used hot water is right there. Creating the loop is fairly easy.

Closed loop solar water heater systems sometimes referred to as anti freeze or glycol systems include the heat collectors insulated piping a circulating pump an expansion tank a hot water storage tank a heat exchanger solar fluid usually a solution of water and nontoxic propylene glycol antifreeze a controller valves and gauges. As the loop returns to the water heater it connects at the low point of the heater. Most new solar homes feature a variation of one kind or another. Near the water heater area a recirculating pump pulls the water from the furthest fixture back into the water heater creating a loop.

This assist consists of having the return pipe from the remote location being smaller than the supply pipe. A continuously operating pump is clearly wasteful. All that is required for this loop to function is for the water heater to be below the fixtures that you want hot water at and for there to be a bit of an assist to increase the loop s performance. This valve is simply screwed into the heater.