Active solar heaters are primarily of three types direct indirect and drain.
Indirect solar water heater 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.
Indirect solar water drainback systems are also a indirect design that use a heat exchanger to separate the collector loop from the potable water.
Solar water heating systems almost always require a backup system for cloudy days and times of increased demand.
Conventional storage water heaters usually provide backup and may already be part of the solar system package.
Some heat loss occurs while the transfer fluid circulates the system.
The optimum installation can be constructed by using different accessories.
The ite as well as the its can be part of a solar water heating system.
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.
Indirect solar system ite.
The indirect solar system ite consists of an indirect tank which is connected to a boiler electric gas or oil or water heater.
6 4 while the swhs which are fitted with heat exchangers are called indirect systems shown in fig.