Solar Space Heater Made From Soda Cans & An Old Window.
Some of you may remember a post I wrote back on my birthday that offered a sneak peek of a top-secret project I have been working on in my garage, and asked you to guess what the picture might be. Here is the picture that I posted on that day:
Well, the time has come to unveil more pictures of project timeline and all its finished glory, followed by some information as to how I made it, what its for, and what I will be doing with it now that it’s done. Let’s first take a look at a few pictures I took as I was building this solar space heater…
So, now can you guess how this thing works? As air enters the 2 holes on the sides near the bottom, the sun is heating up the soda cans all painted black to absorb the heat. The cans have holes drilled in the bottom, so the air being drawn in at the bottom works its way through all the heated cans and gets hotter and hotter as it approaches the top. With convection, more and more air is drawn in through the bottom and the heat rises. A single hole drilled in the top of the frame is where all this heat comes out, and I have to tell you – it’s friggin’ hot and it comes flying out of there at full speed. That’s the basics of how it works. But how was it made? Well, if you cannot see from the pictures, the ingredients include:
One old window frame w/glass intact
Empty soda or beer cans, spray painted black, with holes drilled in the bottom
Duct tape
A piece of insulation
Plywood for the back (I only have cardboard on it right now, so it’s not even sealed properly)
A dryer vent to hook to the top to direct the heat where you want it to go
Small screen to cover the 2 intake holes at the bottom
That’s it – it’s basically a free heater. However, now you may be asking how/where it could be used? Well, what I was initially going to use it for was to heat my garage during the winter, so I could work out there all day without freezing to death. My plan was to lean it up against the outside of the garage, right below a south-facing window, and let it collect the sun’s rays there. And then, I was going to build a custom window-shim out of a piece of wood that would let me prop open the window a bit but keep it sealed, and then cut a hole in the wood to attach the dryer vent to, which would bring the hot air into the garage. Kind of like this:
And finally, if I wanted to, I could mount a tiny fan to blow the heat further into the garage. But judging by the temperature reading coming off the air at the top, I might not even need to do that. It was up to over 105 degrees the other day around 11am. Amazing! And as I mentioned, it’s not even properly sealed yet.
But while that was my idea for it at my house, I think I might give this one away to someone who has trouble affording to heat their home during the winter, so at least they could have heat during the day. I have to do a few more tweaks, and finish the back, but other than that, it’s a solidly-built, indestructible free heat source that should go far to keep someone warm…during the day. Unfortunately, the moon just doesn’t shine bright enough to power it. 
So, what do you think? Did you guess correctly? Thinking of building one of your own for your workshop, garage, or even house? Let me know if I can help. It was quite a lot of work, but totally worth it in the end to know that I built a source of free heat that actually works!
You may also like:
- Heat Your Home For Free With These Solar Heaters.
- Reduce, Reuse & Recycle – Turning An Old Window Into A New Mirror Part 1.
- Reduce, Reuse & Recycle – Turning An Old Window Into A New Mirror Part 2.
- Americans Throw Away 1,500 Aluminum Cans Per Second.
- A Guide To Buying Energy Efficient Windows.
Related Websites
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This is terrific! I’ve seen a version of this on the Mother Earth webpage, but the cans make this even better. The dryer vent is an especially nice addition. Maybe if I start now I could have one ready for the first cool days of fall!
If you’re using standard duck (not duct) tape, it dries out. It would be useful for keeping things in place as you’re assembling the cans, but won’t work for the long term unless the frame and backing keep everything firmly in place.
Is the air fed from outside? I can see where you could use the dryer duct to carry two lines, a feed and a return. That way the start temp is warmer than outside.
Actually, it is “duct” tape – It can be called both, but the official term is, in-fact, “duct” tape, as the “duck” term, from WWII, isn’t verified. The labels on the tape call it “duct”. That being said, it is only there to hold them together for assembly anyway, so it doesn’t really matter.
You could feed both, but that would require multiple lines/holes into the house, which I didn’t want to do. The goal was to make it as easy as possible for someone to use, especially since I am going to give it away.
This is super cool! Or rather, smokin’ hot! I hope it really helps whoever you give it to.
Bravo! I applaud your creativity, frugality, and generosity.
This is so cool. I’m passing it to everyone I know.
WOW, that is kick @ss!! How cool. I really want to give this a shot. Too bad it’s like 90 degrees where I live right now.
exactly what i was looking for to make a solar clothes dryer (rather than a clothesline). just hook the output hose to where the heating element is on a gas dryer. you would still need to use power to run the motor and blower, unless you had a solar power set up for it. i’m gonna try it!
Oh man,you are amazing.This solar space heater looks fantastic.
I am curious how this will work in the winter. June 9th air is what?.. 80-90 degrees there for your heating air up 15-25 degrees. What happens when the air is 30-40 degrees? I have a feeling that it is harder to make cold air hotter then it is to make hot air hotter.
Great idea – I’m impressed with the low cost, simplicity, and efficiency. As far as heating goes, it takes the same solar energy to go from 10 degrees C to 20 degrees C (10 degree C rise) as it does to go from 30 degrees C to 40 degrees C (still a 10 degree C rise). However, there may be more ambient loss at lower temperatures with less than perfect insulation. You should be able to cascade 2 or 3 of these in series – each giving a 25 degree F rise and raise the outside 30 degree air to 105 degrees… Mike
One other value for this device is that if you have another small space heater – elec, gas, etc, you could use this to preheat the air and the space heater would require less energy… MK
I first heard about soda can heating from a video about a Canadian guy who took soda cans and made a big solar air heater:
http://www.youtube.com/watch?v=bRZvAAqzXIw
Here’s his company:
http://www.cansolair.com/
I was thinking, what if you try and apply this idea to something else? My idea would be heating a pool but I’m trying to think of how to feed water through it and it insulating and carrying water to and from the pool.
Good idea Mike – you should give it a shot!
Mike,
I’ve seen similar ideas; but rather than the hassle of trying to seal the cans against water leakage, try using copper tubing painted black.
Or, look for the articles on the guy in China who made a water heater out of beer bottles.
http://www.dailytimes.com.pk/d.....page=20085\13\story_13-5-2008_pg9_8
I haven’t seen a closeup, but perhaps the same idea may work with the cans.
I have come up with a good and inviremental solution to how to get the bottles to sit tight together. I tried to glue but no glue was god enough.
Look at my sight I explain on swedish but you can se how anyway. You can change the language on the front side.
http://off-grid.se./luftsolfangare-med-burkar
Wow! This rocks! I am manking a few of these. I wonder, how this can be used to stop water buckets from freezing in a barn?
I hate dealing w’frozen water buckets. It is so hard on my hands. Don’t want to boil the water or burn the barn!
Hmmm I shall ponder this! Thanks!