Do you have some south facing windows? (North facing if you are
in the Southern Hemisphere), If so you might want to consider some
free solar heat. Don't expect this to eliminate all heating costs
but it will reduce your expenses. The more windows you can place
one of these solar heaters in the more you will see a reduction
in your heating costs.
The main components of this solar heater design are sheets of heavy-duty
foam insulation, one or more sheets of window glass, a tube of "RTV"
(bathtub sealant), a box or two of aluminum foil, and a roll of
duct tape. Exact sizes and angles to cut will vary, depending on
the height of your window from the ground, it's width, and the winter
sun angle at your latitude.
The Heat Collector can be as simple as painting the sun
side of the thin foam panel flat black, or for a more efficient
collector use a sheet of ten-thousandths aluminum (available as
scrap from most newspaper or "offset" presses). Paint
the aluminum sheet(s) flat black on both sides then mount it ¾ inch
from the surface of the foam sheet using a couple of dozen ¾ inch
cubes cut from foam and cemented down with RTV. This allows the
air to pass by both sides of the solar heated aluminum, greatly
increasing the efficiency.
Cover all inside foam surfaces with aluminum foil and glue it down
with RTV. Paint or otherwise cover ALL external foam surfaces.
Foam is sensitive to ultraviolet light and will decompose if left,
unprotected, in direct sunlight.
Be sure and seal the glass top and all other exposed seams with
RTV to insure the assembly is watertight. Moisture in the collector
will reduce its efficiency, and may promote mold.
Use RTV to glue the sides to the bottom panel and end cap. Duct
tape can be used to hold everything in place while the RTV sets
up, if applied along all edges the duct tape can be left in place
to add strength. You may want to consider pushing a few nails through
the side panels and into the thinner inner foam panel to hold it
in place as the RTV sets up.
Cut two foam covers to close the hot and cold air ducts at night
or in the summer. Duct tape makes pretty good hinges and clasps
for these covers. If you live in wind a prone area you may want
to drive two stakes in the ground and attach them at each side of
the lower end of the solar heater to prevent wind lift. Remember
to keep the glass clean for optimal performance.
Notice: The intent of this web page is not to be step-by-step
instructions, but as a source for general information and rough
design ideas. If you are not handy building small projects I would
suggest you find someone who is to help you with this project.