Solar Heating Systems

You've read a lot about it.  You've thought a lot about it.  And you've finally decided to do it.  You want to put in a solar heating system.  No, you're not a "tree hugger" who wants to save the world by decreasing the greenhouse gases that come from the fuel you use to heat your house.  Your area is offering significant tax credits for installing a solar heating system.  You can get both an income tax deduction and a property tax exemption so you're going to go for it.  What now?  What are your options.

Solar Heating Systems:  Active or Passive

Your first decision will be an easy one.  In both active and passive solar heating systems the sun heats a medium but active systems store and distribute the heat via some mechanical means like a blower fan, while passive systems rely on the natural convection properties of air distribution.  In a passive system, air enters the solar collector, is heated by the sun, then enters the room to be heated.  When the sun is shining the air flows back into the collector.  When the sun is not shining, a damper keeps the air in the room.  If you're getting the idea that passive systems are best suited for single room applications, you're right.  If you have an addition that just doesn't seem to get enough heat, a passive system may be approriate.  If you're interested in heating your whole house, an active system is the only way to go.  A well designed active solar heating system can provide between forty and eighty percent of you home's heating requirements.

Active Solar Heating Systems:  Types

Those solar panels you've seen on top of houses in your neighborhood are filled with a medium that is heated by the sun.  The medium is either liquid or air, and those are the two types of active solar heating systems.  A liquid based system uses water or a form of antifreeze to capture the sun's energy in what is called a "hydronic" collector.  Air based systems, as you would suspect, heat air in an "air" collector.

Liquid based systems are generally considered as more appropriate for central heating needs.  Liquid is a much more efficient heat transfer medium than air.  Both air and liquid systems follow the same cycle.  The liquid or air is heated, stored, and then distributed when a call for heat comes.  In air systems heat is most often stored and distributed in a special heat pump.  In liquid systems, special water tanks are used for storage and then distributed through hot water radiators or radiant floor systems.  Radiant floor systems are especially suitable and some well designed ones eliminate the need for a storage facility.  In this case, the liquid does not pass through the solar collector to be heated until it is needed.  The same happens with most air systems.  Solar energy is stored in the air collector and when a call for heat comes, the air then is pulled through the collector, heated, and then immediately distributed.  If you're dazed and confused, try getting in touch with someone in your local area who has a solar heating system installed.  Local contractors can advise you as to which type of solar heating system is best for you.  Good luck with your system!