Have you considered a piece of painted black steel behind the cans? And for the record, I love your idea. I am considering building one to help heat my office during our Montana winters.

If you build one you can make 16 columns of 17 cans per column. After I built mine is when I realized that I could have went the extra. Behind the cans I have a 3/4" foil backed styro foam.

Hello all, I haven't been here for a while, just thought I would update my thread. Heater has not been doing much this winter, months of Nov. and Dec. we only saw maybe 10 days of sunshine. I'm hoping the rest of the winter is better. So far we have had 5 days of sunshine this month already.
When it is sunny it seems to work pretty well. This spring I will take the lazing off and put tin covers over the plenums. The Aluminium tape I used has come unglued and I think I might have some leaks from the plenums to the glazing. I will let you know what I find when this is done.

Thanks for the update!

Historically here December is horrible for sunshine. January and Febuary are great though.

Why are you concerned about sealing between the glazing and plenums?

Hi Doax, I have been noticing some moisture and heavy frost on the inside of the panel. Makes me think that I have a leak. Also when panel first fires up I get lots of moisture coming out of the air outlet which makes me think that there is a plenum leak. It didn't do that last winter and it feals like I am not getting as high of temperatures that I was getting last winter. That and like I said the aluminum tape is coming off. I guess that was the wrong choice to help seal the plenums.

In the solar furnace I built, I have rows of old fluorescent lamp casings painted flat black and incorporated small 12V fans from tossed out PCs to move the air through the 'tunnels', alternating one end to the other. I also have the option to move the hot air through a heat exchanger inside the furnace to a separate coil. My biggest problem is that the sun in upstate NY is very rare and unlike the SVPs, which produce electricity even on cloudy days, I am disappointed with the amount of heat I actually capture.

So you just circulate the air/heat over the bulbs, instead of through, like when using cans.

Is it just as effective?

I think a panel such as this would be an excellent fresh air preheater when ever sun is available. Even cloudy days such heat to near room temp. Not 100% of fresh air needed but quite a bit.

Shop Lamps
 

No Bulbs - I ripped the 110V stuff out. I am just using the Covers as a heat collectors - yes I circulate the air through the 'tunnels' with 12V fans on opposing ends. Essentially the air is being moved up one side and down another - and then into the large chamber. When the sun is shining, I can realize a 50 - 70 degree rise. I've seen temperatures in excess of 165 deg.

What about incorporating a loose continuous loop coil(like in geothermal ground loop design) on top of can to preheat DHW. Would it "steal" much from the air heating performance? Copper tubing best but Black poly pipe would be that less efficient I don't think for the cost savings.