Solar Space Heating
Solar Thermal Space Heating Systems capture the sun's energy to supplement the existing heating system for a home or commercial building. The heating system intensifies the sun's power to heat water or air that is then used to heat the building. While some solar collectors look like solar photovoltaic panels, they are quite different. Solar thermal panels do no generate electricity, but simply absorb the sun's heat.
Types of Solar Space Heating Systems
Hydronic Systems and Air Systems
There are two basic types of active solar heating systems: those that use hydronic collectors, and those that use air collectors. The collector is the device that is exposed to the sun, and warms air or a fluid for use by the system.
These systems are an extension of solar water heating systems. Hydronic collectors warm water or an antifreeze solution by circulating them through a manifold that is exposed to the sun.
These systems are designed to collect and transfer heat to warm the air circulating in the building. As the name suggests, air collectors similarly pass air through a sun-exposed collector, rather than a liquid.
Both hydronic and air systems collect and absorb solar radiation to heated air or a liquid then use the heated air or liquid to transfer heat directly to an interior building space. or to a storage system from which the heat can be distributed. If the system cannot provide adequate space heating, an auxiliary or back-up system makes up the difference. Liquid systems are more often used when storage is included, and are well suited for
radiant heating systems
, boilers with hot water radiators, and even
absorption heat pumps and coolers
. Both air and liquid systems can supplement forced air systems.
Active and Passive Systems
Active solar water heating systems use pumps to circulate the liquid warmed by the collectors Passive systems do not use pumps, but instead use gravity and water pressure to circulate the liquid instead.
Active systems come in two types:
(open loop): water is circulated directly through the solar collectors. This system cannot be used in areas where temperatures drop below freezing.
(closed loop): a non-freezing liquid is circulated through the collectors and heats the water in a tank afterwards through a heat exchanger.