Solar water heating systems almost always require a backup system for cloudy days and times of increased demand.
Indirect solar water heater system.
The indirect solar system ite consists of an indirect tank which is connected to a boiler electric gas or oil or water heater.
Indirect solar system ite.
The ite as well as the its can be part of a solar water heating system.
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.
Some heat loss occurs while the transfer fluid circulates the system.
6 4 while the swhs which are fitted with heat exchangers are called indirect systems shown in fig.
The optimum installation can be constructed by using different accessories.
Indirect systems water is heated directly into solar collectors and circulating in your home it is best suited for cold or freezing conditions where the absence of heat exchangers means that cold cold water cannot be heated effectively.
6 5 16 in a direct system the service water is directly circulated between the water tank and the collector while in an indirect system a heat transfer fluid usually antifreeze distilled water.
Indirect solar water drainback systems are also a indirect design that use a heat exchanger to separate the collector loop from the potable water.
Active indirect systems in which a heat transfer fluid like propylene glycol is heated up within the solar collectors and then transfers the heat to the water supply with a heat exchanger in a closed loop system.