There are two methods of solar heating: active and passive. Passive solar heating garners energy from the sun without the use of mechanical or electrical devices. This is largely done through building structure and design and is advantageous for its low operation and maintenance costs. Active solar heating requires the use of pumps or fans to move and direct solar heat. This article will focus on the active method of solar heating. Active solar heating can be further broken down to liquid-based and air-based systems.
Liquid-based Active Solar Heating
Liquid-based systems utilize liquid solar collectors to trap and move heat. Flat-plate collectors are the most common. The collectors are filled with a fluid, such as water or antifreeze, which absorb the sun’s heat initially. A mechanical controller, such as a pump, transfers the heated liquid through the collector into a storage tank or heat exchanger. Special consideration must be made for the cost, size, durability, and placement of a storage tank. Once there, the solar heat is ready for distribution. This can occur with a central forced air system, a hot water radiator or baseboard, or a radiant floor.
Air-based Active Solar Heating
Air-based systems also use solar collectors, trapping air instead of water to absorb and transfer the sun’s heat. Air collectors operate at a lower efficiency than liquid collectors because air does not transfer heat as efficiently as water. However, air-based systems can heat rooms directly and can function early and late in the day.
Air collectors gather solar heat within an insulated, air-tight metal plate located in a metal frame. The heated plate heats then the air within the collector. All this hot solar air gets distributed via an electrical blower or fan.
Air collectors are easy relatively easy to build. They can be installed outside to heat more than one room. These collectors are usually installed on roofs, window frames, or walls. Contact our Solar Installers to learn more.
Remodeling tweets and photos posted daily. Join Us on Twitter