Indirect or closed loop systems in which potable water is heated indirectly by a heat transfer fluid that is heated in the collector and passes through a heat exchanger to transfer its heat to the.
Direct and indirect solar water heaters.
Solar water heating swh is the conversion of sunlight into heat for water heating using a solar thermal collector a variety of configurations is available at varying cost to provide solutions in different climates and latitudes.
They can be used in any climate and the fuel they use sunshine is free.
Indirect solar water drainback systems are also a indirect design that use a heat exchanger to separate the collector loop from the potable water.
Two types of solar water heating systems are available.
Direct or open loop systems in which potable water is heated directly in the collector.
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.
Traditionally indirect systems are more successful nationwide than direct systems because of their resistance to cold.
Indirect solar water heating systems circulate a fluid typically a mixture of water and glycol in a circuit between the rooftop thermal collector and a heat exchanger that actually warms the potable water.