Do-it-Yourself Solar Air Heater

So, you have weatherized and insulated yourmodification to the photos shown here.
house. You have switched all of, OK most of yourPaint the entire interior of the solar air heater with
light bulbs to CFL's and installed a low flowflat black spray paint.
showerhead. Your programmable thermostat isApply the compressible foam weatherstripping
set for 66° at night and you use a wholealong the face of the entire frame. You may elect
house fan to cool your house in the summer. Nowto use silicone sealant, but this will prevent you
you are considering entering the world offrom removing the glass in the future.
alternative energy, but you don't live on a windySecure the old window sash or glass to the
five acre lot, nor do you have the funds to investframe. Screw directly through the sash to the
in a photovoltaic array or a solar hot waterframe or use 1" long pieces of aluminum angle to
system. The answer to your dilemma is a Solarhold the glass in place. Insert a piece of the
Air Heater.weatherstripping between the aluminum angle and
First you need to determine which window thatthe glass.
you want to build your solar air heater for. ThisNow you are ready to install your solar air heater
type of heater will work in a double hung window,and weatherize it so that you don't loose more
should face south to south west, and should be inheat than you gain. Open the window and set the
direct sun for the greater part of the day. Raiseheater in place. Lower the sash and install foam
or remove the screen and measure the minimumweatherstripping along the line where the sash will
clear opening width.meet the heater. Cut the "air conditioner" foam
If you are using an old window sash, you will needweatherstipping the width of the sash and insert
to scrape off any ole paint, repair the glazingbetween the sashes at the bottom of the
putty, prime and paint the sash, and clean theexterior sash. Next, tuck a piece of plastic wrap
glass.between the air heater arm and the window
Build the wood frame: make it 1 ½" widerjamb, making sure to secure it in place and cover
than the minimum clear opening and 36" to 48"all surrounding surfaces. Fill the gap between the
tall. Or build it to fit the old window that you areair heater and the window jamb with expandable
using. Other designs use insulation for the frame,foam. Finally, install insulating window film over the
but treated wood decking is much more durablewindow, securing the bottom of it to the
so your air heater will last for years and years.horizontal piece of decking.
Marine grade plywood or primes and painted 1x6'sFinally, cut a piece of rigid insulation to fit in the
may be substituted for the decking.top opening of the heater to prevent any
Add the arms that extend through the windownighttime heat loss, or roll up an old bath towel
making sure that they extend far enough so thatand set it into the gap just below the sash. Adding
the air heater can be secured on the inside of thea piece of aluminum flashing on the top of the
window. Follow this up with the remaining deckingsolar air heater will help to keep the water out,
pieces and the 1x4 trim. Seal all joints with sealant.and in the spring you might want to prime and
Cut the rigid insulation back to fit into the frame,paint the treated wood frame.
leaving a 5 ½" gap at the top. Use a chalkMaterials list: 1 - 4'x8' sheet of rigid insulation, old
line to mark the line or a drywall square with awindow sash or glass, 3 - 5/4x6x8' treated
new blade in your knife in order to make cleandecking, 1 - 1x4x8', construction adhesive,
straight cuts. Secure this into the frame with aexterior sealant, compressible foam
continuous bead of construction adhesive. Add 2"weatherstripping or silicone sealant, flat black
spacers along the edges and in the middle.spray paint, foam sealant (Great Stuff), 3"
Add the horizontal rigid insulation between thescrews, 1 ½" roofing nails, metal corner
arms at the bottom, and then one in the middlebead (for drywall), aluminum flashing, "air
of the arms. Again, secure both pieces with aconditioner" foam weatherstipping, 1"x1" aluminum
continuous bead of construction adhesive on allangle, plastic wrap, and insulating window film.
four sides.Optional materials: glazing putty, primer and paint.
Cut the front insulation panel and secure with aTools list: Utility knife, saw, drill, screwdriver,
continuous bead of construction adhesive. Cut theclamps, caulk gun, tape measure, tin snips, chalk
corner bead and secure with roofing nails to theline or drywall square. Optional tools: putty knife,
insulation with the fins pointing out. This is a slightpaint brush.