This started me thinking about the sun and the heat it makes, so I started looking.
It had to be cheep or free. When I saw OhMikes instructable it inspiried me to try my own
I used old fly screens I had lying around and in place of his foil, I re-used aluminium plates from the printing company I work at.
I painted one joined plate gloss black to absorb the suns heat and another plate for the back pannel.
I got it up and running and found it did not have enough air transferring through it so I added a solar panel I just happened to have been given about 10 years ago and a cooling fan from an old photocopier.
The only new thing I had to get which also cost nothing was a meter of shrink wrap which was left on the end of a roll in the packaging dept at work.
It is now heating my kids bedroom in the day time very well and is creating a good flow of warm dry air.
My power bill is now down to $250.00 per month so I think the problem is solved for me and my family.
This is a shot of it outside leaning on the Geodesic dome I made today.