Hi. We use the place under the terrace as Stone Build Garden House.
There is no heating. In summertime the place is OK, but in all the other seasons there is too much moisture and, because of the low temp, there is mold everywhere on the gardening tools.
So I built this heater solution, and it has worked now for 5 years. When the outside temp is 8.7 degrees Celsius, the heated air from the panel is 22.5 degrees Celsius. At 11 degrees Celsius, it is nearly 29.6 degrees Celsius. The panel is exactly turned to face the south, and that's the ideal.Step 1: Woodworking
I used a wooden plate and U-profiles for metal stand walls. A wood strip was screwed around the wood plate to create the frame. Then the U-profiles are clipped around.Step 2: Insulation
For the insulation, I use material you'd normally put behind radiators, all fixed in the frame. The little wood pieces create a distance behind the back and the metal sheets. And there are a few holes to suck fresh air covered with fly screen.Step 3: Metal sheet
The metal plate is 0.5 mm thick aluminium, painted in black and fixed on the little wood pieces.Step 4: Ventilation
A big ventilator is fixed inside the frame. On the outside, there's an adapter to fix the tube. A KTY10 sensor is placed in the air stream.Step 5: Plexiglas
I had this 6 mm Plexiglas sheet laying around. It's not optimal, but I had this one. I think a complete transparent sheet would work better. For a nice finish, I screwed a plastic strip on it.
In the middle of the panel, I added an aluminum bar so that the Plexiglas is more stable.Step 6: Temperature Switch
The temperature difference circuit, I found on the internet. It works with 2 KTY10 temp sensors. When the temp inside is lower than the temp on the outside, it switches the ventilator on and blows the hotter air inside.
If I find the schematics in my mess, I'll post them here.Step 7: Installation
I had already two 125 mm holes in the wall. One on the front side which is exactly the south side and one on the backside. An aluminum tube connected to the solar heater goes to the inside.
I mounted the construction on the wall with 2 metal angles.