Solar air heater for your home made of aluminum pop cans..

[Mladen]

Last year I have built this solar panel and now it is "in production". It works quite well. Does anyone have similar gadget, and I'd like to hear some comments, if someone have experience...
Basically, it is simple couple of rows of pop cans painted in black and covered with glass or plastic. Fan is forcing air from the room into the solar collector and again back to the room... It was my "DIY" project.

regards,

[Fionn]

Looks really professional
Have you measured the input and output temperatures to assess performance?

[Mladen]

Yes I have...temp gain is really significant. Intake is room temperature (around 22 Celsius), and average output is 50-60 Celsius, depending on fan speed and position of Sun. In peak (when Sunlight is direct on panel) is just above 80 degrees.  Depending on dimensions of  solar panel, you can get quite energy(heat) addition to your home.

[Fionn]

Excellent stuff.
How did you connect all the cans together at each end of the panel - did you make some kind of manifold?
Also is the box insulated?
Does it produce any heat without direct sunlight?
Also what country do you live in?

[Mladen]

Hi,

lot of questions... most is answered in DIY giude http://solar.freeonplate.com/solar_panel_DIY.htm
you can check it...
BTW, I live in Serbia...

It is insulated with styrofoam, and yes it produces heat even while partially clouds, but with less efficiency. Do not consider this as your primary heat source... nevertheless, it is best 150 eur investment I have ever make. It will pay itself in lets say 2 years(or less, depending on electricity price) and after that, it will produce free heat for me.

regards,

[gb484]

Am busy collecting beer cans to make one hic! Black ones the best, obviously, but there's a limit to how much strong lager I can drink. What aroused my interest initially was a German site demonstrating a similar panel. He'd constructed an entire wall to heat his place. Well, the Germans are renowned for liking a beer or two, hic!

[billi]

Well, the Germans are renowned for liking a beer or two, hic!

 

True  , but occasionally wine is fine , so any design ideas with bottles 

[Billy]

Can you give me some idea of the fan size, m3 is shifts as the links don't seem to give this or am I missing it?

It is a brilliant idea and I would like to try it to air the bedroom as it gets a bit cold as we seldom heat it. 

Boy dun good.   

billy

[Baz]

Although high on gimic value and getting people interested the can collector is not very efficient in its use of aluminium and actually reduces its efficiency by using the circular collector. Whn the sun is on one side the far side of the can is in shaddow so loses heat into the dead air space and so away. A simple sheet of cooking foil as the seperator in a plate construction would be better.

[Mladen]

The stronger fan is, more heat is transferred from collector to the room. It should be at least 200-250 m3/h, or 3-4 m3/min (same thing). Less fan speed (actually volume of air) would give you higher temp at exhaust, but less heat transferred. Heat would remain at cans and radiated through plexy-glass cover(lost  )

cheers,

[martin]

My view is that the aluminium cans will be better at collecting more heat as they will collect the same amount of sun from far wider angles than a flat surface (just like vacuum tubes as opposed to flatties) - if there is a fan sucking the heating away it'll work fine...

[Mladen]

Although high on gimic value and getting people interested the can collector is not very efficient in its use of aluminium and actually reduces its efficiency by using the circular collector. Whn the sun is on one side the far side of the can is in shaddow so loses heat into the dead air space and so away. A simple sheet of cooking foil as the seperator in a plate construction would be better.

Is this something you have tested, or just guessing? Try to find videos on youtube where many of them tested same thing. Don't be worried about heating of cans. They would be so hot, that you couldn't touch them. Actually, round shape gives them advantage as some part of surface is always directly in sunshine. More important thing is heat transfer from collector to air. As cans have only cut bottoms and tops, with parts just hanging from the walls, airflow has some barriers to hit against and make turbulent flow.
Don't get me wrong, I am not against any kind of usage of solar energy, so I would be glad to hear experiences from someone who has, or has built that kind of collector(simple sheet of foil).

Mladen.

[Rhea View]

You may find this old cola panel post interesting. 

http://www.navitron.org.uk/forum/index.php/topic,6899.msg71819.html#msg71819

[Baz]

The angle of the sun hitting the cans makes no difference/advantage if they are painted black and not reflecting. The argument for round collectors only applies to glass solar water collectors where the reflections off teh glass can be conveniently reduced while making the shape strong enough to hold the vacuum.
I don't disaporve of your set up - just pointing out the cans are convenient but not the optimum design.
There is a thread somewhere on here that does have some comparative results and a link to a site showing that the absolute best system uses a wire mesh (flyscreen) as the collector and arranges air to flow through the mesh to extract the heat giving up to 10% better collection.

[Mladen]

The angle of the sun hitting the cans makes no difference/advantage if they are painted black and not reflecting.

I doubt that :-)