About The Two Methods of Solar Heating
- A simple version of an active solar system
Active systems utilize a pump to circulate water or other fluid heated by solar panels, so some electricity is typically used, making it less efficient from a savings point of view. However, it is a more effective way to heat a home than the passive system, particularly in cold weather. And even though it uses electricity to pump the heating fluid through the system, it uses far less than a typical heating system would, so it does reduce electrical use.
Probably the most common active system is a closed loop, meaning the system is capped and water used for heating the house is heated indirectly from the fluid (possibly antifreeze) in the loop. The major advantage of a closed loop system is that it eliminates the constant flow of water, which can cause lime buildup and other impurities and clog the lines. Therefore, flushing of the closed part of the system isn't necessary and eliminates a maintenance problem.
An active system offers other comfort advantages not easily implemented by passive heating, such as heated floors and baseboard heat. - An example of passive solar heating; azsolarcenter.com/
Passive solar heating applies several components into an integrated plan to heat, in this case, a home or building. The basic premise is simple: Passive heating takes advantage of the fact that the sun is higher in the sky in the summer than it is in the winter. Using an overhang over the building in the summer shades the building from the heat of the sun, keeping the building cooler, like sitting under a shade tree.
The second component of passive solar heating is allowing the sun's rays in the colder months to enter the building to heat a thermal wall, which contains a special glass plate within it. There is a space between the glass and the wall that traps the warmed air inside. Known as a Trombe wall, it typically consists of an 8-inch- to 16-inch-thick masonry wall faced with a single or double layer of glass and an area in between to create heated airspace. Vents in the top and bottom of the wall allow the release of heat and regulation of how and where the heat flows to warm the building. - Cost is the biggest disadvantage of using active solar heat, particularly when retrofitting an existing house, as it requires a significant amount of piping, plumbing and pumping to make the system work efficiently.
You also need a lot of sunlight for long periods of time for the system to work in a comfortable and efficient way. - If you install a residential power system for heating water, it is advisable to have a backup heating system for times when there just isn't enough sunshine to adequately heat the water to warm your home. If the solar system was added after the home was built, there is most likely a primary heating system in place, which you can use when solar heat isn't feasible. If you build your own home based on solar power, include a backup system as part of the design considerations.
Probably the least costly approach is to use a combination boiler that heats hot water on demand when weather conditions don't allow solar energy to be used as the primary source. When weather allows, it can be used as part of the active heating system as a storage tank for the heated water. - A well-designed system will provide 50 to 80 percent of a home's hot water needs (less in winter, more in summer). There should be 10 to 15 square feet of collector area on the panels for each person who lives in the house, and the storage tank should hold up to 30 gallons of water per person. The collector piping and storage tank should be located as close to the backup and distribution systems as possible to minimize heat loss. And, of course, the pipes must be well insulated to prevent an unacceptable amount of heat loss.
There are tax credits available for installing a solar heating system, and, in some states, tax advantages, as well. Do your homework so you know how much money you will save by adding this system.
