Solar heat works by absorbing the sun's
radiation and converting this to heat energy. The concept of air
movement, called natural convection, is an integral part of all
successful solar heating installations. If a solar heating system
works with natural convection, hot air rising and cold air falling,
then the result in comfort level can exceed expectations.
Solar heating can be used to heat the space
in your home or to heat the water in your plumbing system. There are
many benefits to incorporating a solar heating system into your
- Solar heat is environmentally friendly.
- Solar heat does not pollute or produce
- Solar heating helps conserve the earth's
- Solar heat is the best choice for people
with allergy problems and chemical sensitivities.
- Solar heating is stable in price. Once
you have bought it, you are protected from inflation and the
political/economic surprises that come with other fuels.
There are two basic types of solar heating
systems: passive solar heating and active solar heating.
Passive Solar Heating
A passive solar heating design does not
actually include any sort of mechanical heating device. Rather,
passive solar heating functions by incorporating building features
that absorb heat and then release it slowly to maintain the
temperature within the home. These building features, often referred
to as thermal mass, may include large windows, stone flooring, and
For passive solar energy to be utilized
effectively there must also be a means for the heated air to
circulate throughout the home. The natural circulation of air is
usually enough as long as doors are left open throughout the home,
however, sometimes fans are also incorporated into the design to
While these may sound like relatively
simple measures, passive solar heating features can reduce heating
bills by almost 50 percent. And, in many cases, especially if you're
working with a builder who is familiar with the processes of passive
solar heating, building a passive solar home may cost the same as
building a conventional home.
Active Solar Heating
Active solar heating is similar to passive
solar heating, but it is a much more involved process and generates
much more heat than passive systems do. Active solar heating relies
strongly on three components: a solar collector to absorb the solar
energy, a solar storage system, and a heat transfer system to
disperse the heat to the appropriate places in your home.
Active heating systems can be divided into
two categories: air systems and liquid systems. The differences in
the heating systems are in the way the solar energy accumulates in
the solar collector. Liquid systems use a liquid to collect the
energy in the solar collector; whereas air systems absorb the energy
through the air.
Since solar collectors are normally
installed on the roof of the building being heated, it is best to
place the hot air outlet in the ceiling to shorten the duct run. A
system installed in this manner mixes the air in a building like a
ceiling fan in addition to supplying solar heat.
The downside of an active solar system is
that the initial installation costs are much higher, since in most
cases you will also need to install a traditional heating system for
the times when the solar heating can't work–many cloudy days in a
row, for example. Active solar heating systems can be expected to
supply between 40 and 80 percent of your home's heating, depending
on the size of the system you have installed as well as the climate
where you live. However, in the long term you will reap the benefits
(and break even) through significant savings on utility bills.