I know a fellow who wants to build a solar-powered device to heat a room in the winter. He wants to put a large black sheet of some material in the window just inside the room, surround it with an enclosure to capture air heated by the black surface, and then use a small solar-powered fan to vent the resultant hot-air into the room.
I maintain this is little or no better than just letting the sunlight flow directly into the room. The sun will warm up whatever surfaces it touches and end up contributing a similar amount of heat to the room. The only energy lost would be that light reflected back out the window or other exits.
The downside I see of his invention is that it darkens the room.
Overall, no, he’s not going to create any more energy then what the sun is bringing into the window to begin with (now think about a way to create a collector larger then the window…perhaps on the roof). But what it could do is absorb the heat when it’s available and disperse it when it’s not. That is he could heat up his contraption when the sun is shining on it and then when the sun sets he could release the heat from it and put off turning on the furnace for a while.
The only time I can really see this being all that useful is in spring or fall when you have that month or two where it’s about 60-70 during the day but 40-50 at night. At least in the midwest.
I remember back in grade school, a classmate saying that one of her relatives (in Arizona?) had big columns of water set in her house somewhere so that they would get hit by the sunlight during the day and warm up. At night, when the outside temp would drop, they would give off their heat and help keep the house warm. I could be misremembering, I could be making it up, it could just be a bunch of bull she was making up to impress the teacher.
RE: "I remember back in grade school, a classmate saying that one of her relatives (in Arizona?) had big columns of water set in her house somewhere so that they would get hit by the sunlight during the day and warm up. At night, when the outside temp would drop, they would give off their heat and help keep the house warm. "
I believe houses designed for solar efficiency do this. They have large windows and a solid floor, maybe dark granite, that absorbs heat during the day and releases it through thenight (presumably with the shades closed to reduce IR loss.)
The wiki article said the wall can have windows, but it’ll reduce the efficiency. Imagine taking a double pane window drilling a hole at the top and bottom. When the sun is pounding on the glass, you should (in theory) be able to feel a good bit of heat coming out of the top hole. If the back were solid, there would be more, but you’ll still get some.
That’s the whole idea behind double (or triple) pane windows, you’re keeping all that heat outside where it belongs (in summer at least). The Trombe Wall is essentially a giant double pane window.
“Thermal Mass” is the keyword there. I think that article even mentioned using fish tanks to help. Makes sense. OTOH, depending on the fish you stock, you’ll end up paying to heat them anyways. So I’m not sure that counts.
But on a smaller scale, many people will put bricks in their oven to give it some thermal mass if they’re going to be doing something that requires a lot of opening and closing. Say, cooking 6 batches of cookies. It takes longer to heat the first time, but each time you open and close the door after that, it’ll recover faster and cost less to get back up to temp. Also, a full fridge is more efficient then an empty one. If you open an empty fridge the cool air literally pours right out with a full one, all the stuff in there stays cool and there’s a lot less air to pour out. But now we’re starting to get off topic a bit.