Solar Cooling - Air-Conditioning From the Sun
At first glance, solar cooling looks like an oxymoron. However,
the same energy that can provide heat in the wintertime can also
provide cooling during the summer.
Several passive cooling systems have been developed and tested.
At their simplest, they rely on a coolant that absorbs and
dissipates heat from the house. This could be a pool of water on
the rooftop which absorbs seat from the inside of the house as
it evaporates on exposure to the sun.
More sophisticated passive solar cooling systems have a solar
collector which is shaded during the daytime. A storage medium
collects heat during the day and dissipates it at night by
exposing the solar collector to the cool night air.
Since the solar collector must be shaded, a retractable awning
or overhang extension can be installed. Since the system can be
reversed in the winter months, it is important that the solar
collector can be exposed to sunshine if needed.
Solar panels can also be used to operate traditional air
conditioners. As it happens, the periods of intense heat
correspond to the periods of peak electricity production from
photovoltaic cells. As long as you have solar panels which
generate sufficient to electricity, you can operate air
conditioners at no cost.
Solar cooling that does not take advantage of high technology is
another possibility. The Romans used a system of running water
to cool down exterior walls of their houses. The heat of the sun
causes the water to evaporate and dissipate the heat within the
house. This kind of system can be used on walls or on rooftops.
Heating and cooling are two of the biggest expenses for most
households. Using solar energy to reduce this expense makes
sense financially as well as ecologically. The less dependent we
are on fossil fuels for heating and cooling the cleaner the
environment will be.