A few things to think about: You need to punch an intake and an output hole into your house to grab the cooler air, warm it and pipe that warmer air back into your home. So, you want your panel big enough to make that worthwhile, in other words, if you punch two holes in your home for a dinky little panel that gives you an itsy amount of heat ONLY when the sun is shining and then leaks heat at other times, you're going to regret them holes, or wish you had of held out for a more worthwhile sized panel... As I mentioned, my panel has about 90 cans and I'm looking forward to finding out how effective it is... Mine is set into a porch area, so not quite as big a deal as punching right into the wall of the house proper.
Another thing you can do is put the panel inside a window in the house without installing it.- in other words just prop it up in a window... The only drawbacks would be that it would obscure your visibility through that window and there may be some concern about whether the extra heat in the vicinity might weaken the seal on your window. I only say this because I once was going to apply a opaque sticky paper on a window for privacy, but then read a caution that it wasn't to be used on dual pane sealed units...
On the other hand some of the plusses with indoor system of propping cans inside is that you can make a lightweight box with just cardboard & cans, doesn't have to be weatherproof, don't have to punch any holes in walls and don't have to deal with the system possibly siphoning off heat at night or when the sun's not shining.
What do you think?
I would think that any heat generated by a panel inside the home would be the same as any solar heat absorbed through a window in the home anyways. The amount of passive solar radiation making it through the window would be the same. Having the panel in the home would not make a difference. You would probably feel the hot air coming out of the panel, but only because the heat would be concentrated. There might be a use for that, like a drying rack for a food dehydrator or something.
Basically one of the can-panels seems like having an extra window without having the extra window. A good idea for unused surface area, like roofs and exterior walls. But I wouldn't bother making one to set up inside the house.
Right now I am in the process of trying to gather up enough cans and making the a small form to initially just do a 50 can unit for experiments. I have a couple ideas about the layout to see what sort of results each produces. I will simply follow the instructions seen in the video linked above for the 1st unit. Then I want to experiment with some modifications to the box as well as to how the air flows through the cans and back into the house. Once I have it up and running I will post pics and information as well as results.
Being that we currently live within the city and I just do not see this going well sitting out front of our house, I am looking at this as an option to heat a small green house and to see if/how it would work for helping to allow 4 season growing.
salix, it seems you are right, the same amount of heat would enter, the inside panel just concentrate it. Or, would it be that the black would up the net indoor heat gain if by nothing else than not reflecting rays back outdoors? If this was the case, maybe it's a negligible difference anyways.
salix, it seems you are right, the same amount of heat would enter, the inside panel just concentrate it. Or, would it be that the black would up the net indoor heat gain if by nothing else than not reflecting rays back outdoors? If this was the case, maybe it's a negligible difference anyways.
Yeah, I think you could get the same results in 'felt' heat by having dark tiles on the floor, or even just a dark rug spread out in the sun in your house.
If you go to the trouble to make a panel, it should probably be mounted on the exterior of your building.