Solar Air Heating Collector for Our Stone Build Garden House





Introduction: Solar Air Heating Collector for Our Stone Build Garden House

About: Build useless things since 1980

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 everywere on the gardening tools

So I build this heatersolution, and it works 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, nearly 29.6 degrees Celsius.

The panel is exactly turned to the south, and that's the best place.

Step 1: Woodworking

I used a wooden plate and U-profiles for metal stand walls.

A wood strip screwed around the wood plate to create the frame. Then the U-profiles are clipped around.

Step 2: Isolation

For the isolation, I use material, you normally put behind radiators. All fixed in the frame. The little wood pieces create a distance behind the back and the metal sheets.A few holes to suck fresh air cowered with fly screen

Step 3: Metalsheet

The metal plate is 0.5mm thick aluminium, painted in black and fixedon the little wood pieces.

Step 4: Ventilation

A big ventilator is fixed inside the frame. On the outside an adapter to fix the tube. A KTY10 sensor is placed in the air stream

Step 5: Plexiglas

I had this 6mm 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 finished, I screwed plastic strip on it.

In the middle of the panel I added an aluminum bar, so that the Plexiglas is more stable

Step 6: Difference 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'll find the schematics in my mess, I'll post them here.

Step 7: Installation

I had already two 125mm holes in the wall. One on the frontside 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,



    • Water Contest

      Water Contest
    • Oil Contest

      Oil Contest
    • Creative Misuse Contest

      Creative Misuse Contest

    12 Discussions


    2 years ago

    Do you have any information about the temperaturedifference switch you used like the maker, part number, where ordered it ANd/or the price?

    3 replies

    Hi there Conrad, just thought if you ever build another, you might like to consider one of these

    I received one of these by mistake, I'd actually ordered a speed controller, but it looked interesting, so I kept it and ordered another speed unit

    A very good explanation on how it works, Thanks


    Thanks so much. For another project (keeping a garage cool) I'm trying to decide between something like this, something with a display like they sell at, or something based on a Raspberry Pi.

    For effort A+. For overall system with controller A+. For the solar heating panel B+.
    There are now lower cost methods and less parts to fabricate the panel to achieve even better results. A solar screen absorber found here may help your next build and other people too.

    However, as a total system, you have a great setup! This I like very much. Thank you for sharing!


    2 years ago

    Hi, guys. Thanks for this project. So as to understand the process (and forgot my poor english, please), the layers are: wood, isolation, "air" and finally glass, aren´t them? And for take the heat air into the house, you have to put the ventilator.. .where? doing a hole in the piece of wood and the isolation layer, until the air chamber?. But, does the whole system is hermetic? If the ventilator pulls heat air from the chamber, where it comes from? Outside? Thanks for your advices.


    2 years ago

    Very very cool - I am considering this option for house heating. We live in a sub tropical climate. But still winters can sometimes be cool enough to require heating.


    2 years ago

    Plexiglas (PMMA) can absorb up to 100% of Infrared light spectrum. This is a lot of energy wasted.
    i would go for real glass if you want to further improve your collector.

    2 replies

    On the pictures we can see multiwall polycarbonate sheet, not plexiglass. And the transparent polycarbonate not absorb infrared light (on the contrary). However cheaper than glass.

    okay, nevermind. i thought i read about Plexiglas in the text somewhere...
    policarbonate is fine.. not as good as glass though. :)


    2 years ago

    What about Lexan? Is it better than PlexiGlass as far as infrared absorbtion?

    1 reply

    I've had polycarbonate double walled glazing on my collectors for 25 years, and they're still working.