Home Brew Solar hot air heater
Solar Pop Can Air Heater
A very effective solar hot air heater to heat your home, chicken coop or where ever you need heat.
this project is cheep to build and only takes 2 to 4 hours to build.
the materials you will need are
- double pane glass window.
- 2x6 lumber
- plywood
- Styrofoam or cardboard
- optional tape to seal Styrofoam seams
- Great stuff spray foam
- flat black spray paint
- Nails and screws
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Rembrandt
| 30 Oct : 19:32
how is the fan wired and what is its power supply? guess i dont understand that part. sorry.
Reply to this Bryan
| 01 Dec : 01:15
the fan is a 12 vdc it is out of a computer power supply.
the fan runs off of a small solar panel.
Reply to this PbIntoAu
| 21 Dec : 14:36
Thanks for taking the time to post this great set of instructions. This is the only one of these things I've ever seen, so I need a little more clarification. In the ninth picture (Captioned: "OK make sure you leave at least 2 inches at both ends to allow airflow.") it appears that the cans at the very bottom of the stack still have the bottoms in them. Am I seeing this right? Are the tubes closed at the bottom or not? I assume they are open at the very top, heating the gap at the top. The fan moves the hot air out of there. (I think that's what I'm seeing in the 12th picture.) Thanks!
Reply to this Bryan
| 29 Dec : 00:47
Hey PBINTOAU
sorry for the long wait on the reply.
both ends of the pop can tubes do have holes in them to allow cool air in and hot out.
I know the photos don't show that well I will try to get a better photo of it.
Bryan
Reply to this dixygirl
| 16 May : 07:58
I have seen another version of this that uses a wet dry vac tube or a drainage hose to vent the air into the house. This can be connected to the hvac vents in your house.
A good place to run the tube in the house is through the attic vent, especially if the panel is on the roof.
[ edited 16 May : 08:04 ]
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LarryP
| 19 Oct : 01:43 What you've there is a flexible steel tube designed for the exhaust lines on high-vacuum systems - such as those used in semiconductor fabrication systems (micro-chip factories).
It's use in passive/active (non-powered/powered) solar projects would yield minimal gains.
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Willis 333
| 06 Sep : 09:10
Great invention, props to you!!! Quick question, on either ends of the cans- is there an open space between the divider and the cans, or should it be air tight? I'm guessing air tight so the cans will hold the heat and act as a radiator? Thanks and you are a genius! Willis
Reply to this mister406
| 12 Sep : 12:46
Hello,and thanks for the pics. I am currently building one of these for my garage. A few questions..1-is there an open space between the top of the cans,and the top of the box? 2-does the fan suck fresh air in while it discharges hot air.3-is there any evidence of the smaller the hole,the hotter the discharge,4-have you had a chance to use this in the wintertime? I am curious if it is really worth the effort if I,m only going to get a temp in the 40,s or 50,s thanks jerry
Reply to this Bryan
| 13 Sep : 16:22
I am gonna answer both Willis333 and Mister406 .
the idea behind the divider is to force the air being sucked into the pop can heater through the pop cans.
not over the pop cans.
the fresh air is sucked in by the fan on the hot air side, so in other words. the fresh air enters through the bottom of the solar heater , through the pop cans and out through the fan. the fresh air picks up it's heat through the aluminum can wall.
and yes if you restrict the air the hotter the air, But you want to keep the air moving and keep a continuous cool air entering the heater. more of your heat will be recovered because greater the temperature difference quicker the air can wick away the heat.
I believe it is one of the cheapest heaters you can make .. and it is well worth the effort.
you can install this in your south facing windows and heat your home and at night you can help keep the heat in.
the only draw back is that you block the light.
I am using this heater to heat the chicken coop during the winter.
I hope I answered your questions in a manner that could be understood.
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mister406
| 26 Sep : 07:39 Hi Bryan, Thanks for being so quick to answer. I understand what you are saying about the fan,however, I am not sure about the size or power of the fan needed. My panel of glass is 3.5 ft. x 6.5 ft. It is an old sliding glass door. I plan on useing this to help heat my garage.That is why my 1st project is going to be so large.I was thinking about a 3" pocket at the bottom to collect a mass of air, then a 3" pocket at the top to fill with hot air for a fan to blow out of the exaust vent by useing a side mounted fan. Does this make any sense to you? Thanks Jerry
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Bryan
| 03 Nov : 18:58 Hello Jerry
If I understand you correct your way going about it should work well.
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LarryP
| 19 Oct : 02:05
Very nice design! My concern, however, is for health. When used at high temperatures don't you notice a chemical odor? If so - that's the foam 'outgassing' - releasing its constituent chemicals into the passing air. (Could cause illness)
You may also run into some problems at higher temps due to the 'muffin fan'. Excessive temps may cause breakdown.
It DOES look to improve upon the old design (circa 1970) where we cut the cans in-half, nailed them to the backing and covered with glass. That design allowed the interior of the (painted black) cans to act as 'heat-wells' with passing air drawing on that heat as it traveled from bottom to top (of the panel).
THAT design used the cans' interiors and exteriors but lost considerable heat to the glass as the heated air flowed along the inner surface. Channeling it through the cans (isolated from the glass) should yield better results. - bravo!
How about covering the frame with a curved cover rather than flat? Depending on the angle of the Sun - the flat glass may reflect much of the IR energy whilst a curved one will REFRACT more of the energy INTO the frame. There ARE curved transparent plastic covers available - usually used in greenhouses.
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Bryan
| 03 Nov : 19:04 I made this solar heater on the cheep, with materials that were easy to obtain. the curved glass would improve the efficiency but i was looking for cheep.
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Bryan
| 03 Nov : 19:22 After the paint and foam had cured I have not had any odor of chemicals.
Over a year of this pop can heater running, the fan is still working. the fan I used is a fan out of a computer power supply. it is designed to take a fair amount of heat. and when it dose break down it is real cheep to replace,
Just go down to your local computer store and ask to buy the fan out of a power supply, they probably have a pile of them in the scrap bin.
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Nico
| 21 Oct : 11:15
Hi Bryan,
What a great idea! Thanks for the detailed instructions
I was wondering why the pop cans are needed - is there an advantage to doing that instead of just painting the back of the box black? A previous post (larryp) says it's so that heat is not lost through the glass, but the heated air layer is still up against the glass. And the fan is solar powered, so it stops moving the air once the sun stops shining, so heat lost at night is not an issue.
Thanks!
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Bryan
| 03 Nov : 19:11 Nico
the pop cans do several things increase the surface area exposed to the sun,the aluminum is a good heat transfer material (coper would be better but expensive ) duct the air through the cans.
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shearwater | 20 Jan : 13:03
I made a collector from cleaned burned out florescent tubes painted black on the inside. This worked very well and kept my unheated garage attic above 40 degrees F all winter . . . day and night. The tubs are attached to intake and output manifolds drilled with a 1 1/2 inch hole saw. These are difficult since they require a lot of work. But they require only one sheet of glazing because the heated air is confined within the cross section of the tubes.
Reply to this LB in Canada
| 20 Apr : 20:27
I've seen a video on yooutube of a fella who has a factory making these. He uses silicone to join the cans and drills out the ends (faster?) He also uses a curved plexi over the cans and a stronger fan. I prefer the solar one presented here to really get off the grid.
As for cold temps, the cold air is drawn from the bottom of the house to have a higher temp output and pumped into the toplevel of the house.(Not the attic. If your attic has a vapor barrier, you could cause condensation problems and the rest of the house would not heat).
To see his project, go to
http://www.youtube.com/watch?v=bRZvAAqzXIw&feature=related A combination of both these projects might yield even better results.
Reply to this Da Shadow | 22 May : 04:04
I was wondering if anyone could critique my idea. You can look at it here.
http://picasaweb.google.com/lh/photo/RvCUiqohDF-DxjdjdEZdPQ?feat=directlink Reply to this matt w
| 02 Dec : 17:17
Bryan,
Thanks for the photos etc. I am curious how it worked in the cold.
Is there anyway you could quantify the amount of heat it produces? I'm just trying to get a sense of how much square footage of heater would be required to make a dent in a rooms heating needs.
After having a few seasons under the heater's belt, are there any modifications you would suggest.
Thanks a bunch,
matt w
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Bryan
| 02 Dec : 22:13 Hey Matt
if you are heating air in your home you would want to circulate air from your home into the solar heater then back into your home.
usually around 50 degrees increase in temperature.
if I were to change anything i would not install the white Styrofoam inside the wood box. it gets so hot that it will melt regular white Styrofoam
I built this solar heater on the cheep so I just used what I had around at the time.
everything else has held up so far.
tin would be a good upgrade instead of the corrugated plastic.
a better fan or more of them would be good
other than that I i would build it basically the same
Bryan
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matt w
| 04 Dec : 15:30 thanks for the response Bryan. I am going to build one. cool ass website, btw. Will let you know how it works in (often gloomy) western PA.
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matt w
| 04 Dec : 16:30 One more question [for now ]. I'm curious of how the solar panal that drives your fan works. I presume that it only runs when the sun is shining. If this is true, I imagine it is possible to put a valve in that will only open when the sun is shining and the air is heating in the panel.
Would it be possible to have enough power in a fan to open a valve while still using a cheap solar panel?
Thanks again,
matt w
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