Archive for the ‘Solar Garage Heater’ Category

The long cold winters in Ohio make it uncomfortable to work in my garage workshop.
Here is my solution for the problem! This solar heater should take the chill out of the air
while also being super cheap to operate.

Solar Heater-1

Solar Heater 1

Beginning the project…

Beer and Soda Cans for Solar Heater

Beer and Soda Cans for Solar Heater

I started out by collecting about 160 cans. Pop cans, beer cans, anything goes!
The bottoms were drilled out,  tabs were removed, and everything was washed.

Box for Solar Heater

Box for Solar Heater

Next I built a box. My box is 77″ x 43″ x 7.5″
The size of this box was determined by the size of the glass being installed.
My glass was recycled from a neighbor that removed a sun room from his house.
I cut a “rabbit” around the box so the bottom and glass will be recessed.
All joints were glued and stapled. The corners were reinforced with steel angle joints.
After the build was complete, everything was sealed with silicone and then painted
with several coats of exterior latex paint.

Holes cut for ductwork for solar heater

Holes cut for duct-work for solar heater

Four-inch holes were cut out in the top and bottom sections of the box. These holes
will accommodate the air ducts.

Duct-work inserted into hole in the solar box

Duct-work inserted into hole in the solar box

The air ducts are glued into place. Four-inch dryer ducts are used for this.

Snap disc thermostat for solar heater

Snap disc thermostat for solar heater

A “Snap Disc” thermostat will be used for this build. This will automatically turn on the
system fan when the air inside of the heater reaches 115-degrees Fahrenheit and then turn it off again when the air drops below 109 degrees. This item was purchased on eBay.

The Snap Disc Thermostat is installed

The Snap Disc Thermostat is installed

The thermostat is mounted into the upper air duct. It will be wired in a later step.

Special Nails with clips for holding insulation in place

Special Nails with clips for holding insulation in place

These items were used for attaching insulation to the box. It is basically a nail attached to a piece of tin. Several of these are glued to the sides and bottom of the box. The insulation is simply pressed into place onto the nails and the crimped piece is clamped onto the nail. (One of my neighbors gave me these! I’m not sure what they’re supposed to be used for!)

Beginning to install the insulation into the Solar Heater

Beginning to install the insulation

Insulation is installed onto the sides of the box. I used “duct-board” insulation that I got from an HVAC contractor. It comes in large sheets that can easily be cut to size. It is a rigid foil-backed fiberglass insulation about 1-inch thick.

Wiring the snap disc thermostat

Wiring the snap disc thermostat

Before installing insulation onto the bottom of the box, I connected the thermostat wires. These are routed to the bottom air duct where the system fan will be located. These wires will be beneath the insulation for protection from the heat that will be generated.

The insulation installation is complete

The insulation installation is complete

Insulation is installed into the bottom of the box. All seams are then taped with foil duct tape.

Underside of the duct

Underside of the thermostat

Thermostat wiring protruding from duct

Thermostat wiring protruding from duct

The box is now flipped over and the air ducts are sealed with silicone. Note the thermostat wires protruding from the air duct.

Beginning the solar manifold

Beginning the solar manifold

Each air manifold is built by assembling two pieces of gutter that are cut to fit tightly between the sides of the insulated box. These two gutters are then glued together with silicone. Two of these are needed. One for the top and another for the bottom.

Holes are cut into the manifold

Holes are cut into the manifold

Another hole is cut in manifold

Another hole is cut in manifold

Holes are cut into the manifolds to accommodate the cans. A 4-inch hole is cut to accommodate the air ducts. Finally, the manifolds are painted with a high temperature, low gloss black to better attract the heat from the sun.

The solar manifolds are in place

The solar manifolds are in place

Each manifold is glued into place and attached to the air duct.

Preparing and Stuffing Cans into downspout pipe

Preparing and Stuffing Cans into downspout pipe

Downspout pipes are cut to fit between the two manifolds and then painted with the same black. (Sorry, I forgot to take a picture of that!) Downspout pipe comes in 10-foot lengths, so I was able to simply cut them in half and use the 5-foot lengths. I used silicone to glue one of the prepared cans into one end of each pipe, making sure that half of the can still protruded from the pipe (to fit into the manifold later). After this dried, I added more silicone insuring that this end of the pipe was completely sealed around the can.

Afterwards, the remaining prepared cans are inserted into the downspout pipes. By inserting cans into the pipes, all air passing through will be slowed down giving it more time to be heated. I cut slots into the sides of a few of the cans to allow more of the air to enter the pipes instead of just passing through the cans. Before placing the last can into each pipe, I insured there was enough room to slide it back and forth a couple inches. This allowed me to place the downspout pipe into position between the manifolds and then pull the can out to lock it into place. Also, to give this final can more stability, I squeezed another can inside of it to double up it’s side walls.

Downspout Pipes - Top Section

Downspout Pipes - Top Section

Downspout Pipe - Bottom Section

Downspout Pipe - Bottom Section

After all pipes are in place, silicone is generously applied to seal the final can into place within each of the downspout pipes. When this has dried completely, more silicone is added to completely seal the can into the manifolds. My goal was to make these seals as airtight as possible. This kind-of reminds me of the Lincoln Memorial!

Solar Heater installed and in place

Solar Heater installed and in place

The heater is mounted into place and the glass is installed. Prior to this, 4-inch holes were drilled through the aluminum siding on my house to accommodate the air ducts.

Power Switch and Air Intake

Power Switch and Air Intake

Solar Heated Air Exhaust

Solar Heated Air Exhaust

On the inside of the garage I installed a 35-watt dryer duct booster fan to pull air into the heater via the lower air duct. For the upper air duct, I simply installed a dryer exhaust vent. The light switch as installed so that I can simply disable the heater whenever desired.

Dual Probe Digital Thermometer

Dual Probe Digital Thermometer

Finally, to monitor the heater, I installed a dual probe thermometer. This was purchased on eBay and installed into a Radio Shack project box. One of the probes was routed to monitor the input air temperature while the other probe will monitor the output temperature.

Solar Heater Working

Solar Heater Working

11-6-2010 – Today the outside temperature was 39 degrees and a bit overcast. The air going into the heater was 48 degrees when this picture was taken. Output temperature is 169 degrees! 121 degrees difference! Success!