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Solar Space Heating Page
Solar space heating is more difficlut to accomplish in a retrofit situation than water heating for a vaiety of reasons:
| Orientation | For solar heating to work, one side of the building needs to face south, perferably the longest axis, so that the collection area will be as large as possible. |
| Exposure | A building that is shaded by some object(s) will not recieve much solar heat. |
| Construction | A building may be constructed so that it is difficult to modify it to let the sun into its interior, such as masonry or log construction. |
Before adding solar heating, the home should be made as energy efficient as possible. This will not only make whatever system that you install carry a higher precentage of the heating load, but will reduce the cost of heating now. With the way energy prices are going, you cannot afford not to do this now.
Retrofitting an existing home is possible, even in less than perfect conditions. Below is a photo of a home retrofitted with a sunspace and a hot air collector
This photo shows the porch that was enclosed to form a sunspace. On the second story wall above the porch roof and the overhang of the main roof, an air heater was constructed.
Air warmed by the sunspace is pulled by a fan through the air heating collector, then this heated air is blown into the house. The temperature of the air entering the home is often greater than 120oF.
On sunny days, no other heat is needed at outside temperatures above 20oF.
Although no heat storage is provided, the materials of the house will store heat for some time after the collector has stopped running for the day. In the early fall and late spring, no other heat is needed, as long as the night time temperatures do not drop below 40oF by bed time.
It should be noted that this house does not have a perfect south facing alighnment. It faces about 24o degrees west of south. This still is close enough to give good performance. About 4 to 5 hours of operation on a winter day.
The collector design was inspired by Rhodale Press's New Shelter, which was published in the early 80's. It was called a clear view collector.
To the left is a sketch showing where the collector was added between the two existing roofs.
This collector is a boxed in and glazed area of wall with an absorber plate hung in it. Air is pulled by a fan through the collector and blown into the house. The fan is operated by a remote blub thermostat, when the temperature in the collector rises to 90oF, the fan turns on, at about 85oF, the fan turns off. In the warmer months, when the heat is not needed, the power to the fan is turned off and vents are opened to prevent overheating. One of these vents can be seen in the photo above, on the very left of the collector. This collector carries about 25% of the annual heating load. The rest of the heat demand is supplied by sunshine in solid form, wood burned in a stove.
About three to four cords of wood per year are used. If wood heat is used, it should be burned is a stove that will burn it a clean as possible, such as one equipped with a catalytic converter. Otherwise the smoke that you are sending up the flue is some of the fuel that you had to cut or pay for. A clean burning stove will usually save you 25-30% of the wood that you would have to burn, not to mention the reduction in air polllution. If you have wood avialable locally, it makes economic sense, even if you have to buy it, the money helps your local economy, rather than that of OPEC members.
email me at SLee529282@aol.com.
