Solar Air Heat Systems
Like solar hot water systems, solar air heat systems use solar collectors to absorb the sun’s energy then pump that heat throughout the home using fans.
There are two types of active solar heating systems which use different heat transfer mediums: air is used for solar air heat and water is used in solar radiant heat systems. Both systems use their respective heat transfer medium to absorb heat in the collector, which is used to heat the home. Here we will be talking specifically about air heat systems.
The systems are traditionally called “air heaters” because they use fans to circulate the air heated in the collectors throughout the home. Typically these types of systems are used to warm individual rooms with the air collector place on an exterior wall or roof in close proximity to the room it is used for. New technologies however are being developed to make air heating available for the entire home.
The great thing about air collectors is that they never freeze, rarely experience leakage problems, and produce more useable heat than a liquid system (i.e. they can provide heat earlier and later in the day). The caveat though is they are not as efficient as solar liquid heating systems because air is a poor heat transfer medium.
How to Choose a Solar Air Heat System
Installation of a solar air heat system is just like any other solar installation: it depends on many factors. Things to consider are your local climate, the size and efficiency of your solar air collectors, and the temperature you like to keep your home.
A good rule of thumb to ensure you implement the most cost effective option would be to install a system that at least covers 40% of your heating needs, however there are systems that can often serve up to 80% of your home’s needs.
Active systems are the best option for households living in areas where there is adequate sunlight and where heating is needed most of the year. This can generate a sizable savings in energy costs when converting from traditional heating systems which use non-renewable energy resources.
Anticipate spending between $30 to $80 per square foot of collector area installed. Solar air systems are the simplest to install and less expensive than solar radiant heat systems which use liquid as the heat tranfer medium, but are not practical for areas with long heating seasons.