Solar Thermal (Hot Water)

Specially popular are the domestic compact equipments, composed typically by a warehouse of approximately 200 or 300 liters of capacity and one or two collectors of one or two square meters. These equipments, available so much with circuit opened like closed, can give 90 % of the needs of warm annual water for a family from 4 to 6 persons, depending on the radiation and the use. These systems avoid the emission of up to 4,5 tons of noxious gases for the atmosphere. The approximate time of energetic return (necessary time to save the energy used in making the device) is one year and a half approximately. The useful life of some equipments(teams) can overcome 25 years with a minimal maintenance, depending on factors as the quality of the water.

It is usual to find facilities in which the accumulator contains an electrical resistance of support, which acts in case the system is unable to attain the temperature of use (usually 40 º C). Some countries sell equipment using gas as a support.
The structural characteristics of the collectors respond to the minimization of energy losses when the heated fluid passes through the tubes, which are isolated to drive (empty or otherwise) and rerradiación low temperature.

Besides their use as hot water, heating and cooling (using absorption machine), the use of solar thermal (generally inexpensive materials such as polypropylene) has proliferated to the heating of residential swimming pools, in countries where legislation prevents the use of other energies to this end.


In many countries there are subsidies for the domestic use of solar energy, in which case a residential installation can be amortized in about 5 or 6 years. On September 29, 2006 came into force in Spain the Technical Building Code, which provides for the compulsory introduction of hot water systems (ACS) with solar energy in all new buildings, to comply with the protocol Kyoto, but forget the heat, as embodied in the ordinances of the City Councils solar.