You may not believe it, but it’s true. I built this myself a few years ago, and you can still do it today for under $50. So let me say first, that this is a hot air generating solar heater, not electric. The build is very simple, and the average Joe with basic ‘home owner’ tools can easily put this together. When you stand by a well insulated window in the dead of winter with the sun shining through, you can feel the warmth of the sun. Well that’s the principal and from there you can construct your panel with that in mind.

Basic materials are:

– 1 sheet 1″ x 4′ x 8′ Celeotex Thermax TF-610
– 1/2 sheet + 3/4″ x 4′ x 8′ Celotex Thermax TF-610
– 1 tube Liquid Nails panel adhesive
– 1/2 tube silicone caulking compound
– 16 Sheet Rock screws
– 1 Plexiglass to fit panel
– 1 all metal aluminum duct tape
– 1 Can High temp black header paint
– Assorted Wood, scrap pile stuff

You can vary this list based on your design. I used furring strips to create the frame, and Styrofoam instead of the Celeotex. I’m always thinking cheap, but useful. One of the limiting factors is the size of your window. If you have a skinny little window, then your panel can’t be too much larger than the opening. This was a problem I had at my location, my window opening was only 19″. But I was able to make it 80″long.

Panel is constructed with two chambers, one on top, with the glass and painted metal sheet, and one under that draws in the cool air from the room. There is a 4-6″ opening at the bottom of the panel between them for the cool air to travel across the heated plate and be warmed.

The small panel, only 1520 sq inches or 10.5 sq ft, was able to heat 3 bedrooms and a bathroom! So despite the small size it sure was powerful. You may be wondering my location and thinking, sure you were in Florida or Arizona! No, I’m located in the chilly, gray northeast, southern New England, a little spot known as Rhode Island.

A few building tips; You need to keep the panel off the ground, bugs, rodents and moisture. Also calculate your proper angle for your latitude. Here is some help with that. The winter season has the least sun, so you want to make the most of it. To calculate the best angle of tilt in the winter, take your latitude, multiply by 0.9, and add 29 degrees. The result is the angle from the horizontal at which the panel should be tilted.

The best place to get you latitude is at Google Earth, it appears at the bottom of the window and is followed by N. One modification that made a big difference was the addition of an old squirrel cage fan and a thermostatic switch. The fan was free and the switch I purchased at a HVAC supply house. The switch was preset to come on at 120º and off at 80º, it was one of those button, non adjustable sensors. You’ve got to try this out, it’s just a few hours and very little money. Best vacuum pumps