Window Box Solar Heater?

I was just directed to this eight year old YouTube video and so I came here and searched a little to see if it's a well-worn subject and didn't come up with any hits. Is this a normal thing? Do you have things like this? How well have you found them to work?



I also wonder how hard they are to brace and stabilize without a roof right under it and with snow load. And also how much a low overhanging roof hinders their heat-generating capacity.  I think I have just one window that faces the right direction and isn't too shaded, but the idea of free heat is appealing.

And is bigger universally better? how do the dimensions affect efficiency?

I was at a small furniture shop and they made miniature greenhouses for their windows on the south side of the building.  I could feel the warm air next to them.  They used a window with a gap at the top and the bottom.  They could shut them up for the night time.  I imagine it helps keep heat in at night too.

Oh yeah, I can see the gap above and below a double-hung window being useful to create a chimney effect. The one window where I think could be valuable at my place is a side-slider, and also a kind of important view, so I'm not sure that I'm going to pursue this, but I might even knowing it won't be permanent, just to see how it works.

Christopher Weeks wrote:

This video example is fantastic, Christopher. Please, if you try this, report back your experience.

I've never seen one of these! It's very cool! Thank you for sharing!

Great idea! I agree that areas with heavy snowfall it would need some strengthening. Would be interesting to try it out. My next home has a couple of south facing windows that it might work in.

Thanks for sharing! I’ve been thinking about this general idea recently, too.  Mother Earth once had some plans for a solar heater to fit in windows.  It was a flat system (like a black window) that hung below the window.  It had a separator inside that allowed for a chimney effect drawing cold air from the room and releasing warmer air back in  -all in only a couple inches of vertical space at the bottom of an open window.  Maybe you can find that or when I have some time I ll try and look it up and post it.

Thanks again. I look forward to what people have to offer for similar ideas.

A few years back I had a neighbor with something similar.  He liked it.

Robin Kellygoss wrote:Thanks for sharing! I’ve been thinking about this general idea recently, too.  Mother Earth once had some plans for a solar heater to fit in windows.  It was a flat system (like a black window) that hung below the window.  It had a separator inside that allowed for a chimney effect drawing cold air from the room and releasing warmer air back in  -all in only a couple inches of vertical space at the bottom of an open window.  Maybe you can find that or when I have some time I ll try and look it up and post it.

Thanks again. I look forward to what people have to offer for similar ideas.

Here's the link, Robin: https://www.motherearthnews.com/diy/diy-solar-heating-zmaz77sozgoe/

Edited to add - maybe not so good, as they are selling the plans and it's based on a specific brand of insulation board, like an advertorial. But there's probably enough info in the article to use as a starting point.

While looking for this one, I also saw a design that was mounted flat on the wall, not over a window, with vents at top and bottom.

I like that the one in the original video Christopher posted also works as a solar cooker.

The Mother Earth thing looks like the 'heat grabbing' potion of a solar dehydrator just attached to a window so there should be plenty of guidance out there on it.

Brilliant! As I am tech illiterate I can’t figure out how to get to the original thread to congratulate her.

I am about to pick up 2 3M x 1M hot air boxes designed to sit on a roof and blow warm air into a house.
They were not a commercial success and I am planning to experiment with them.
Has anybody had experience with something similar.
They loo like a flat panel solar water unit about 300mm thick, similar to those units sometimes stand next to windows and pushing hot air through the open window?