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.
AMORTIZATION
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.