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Comment by Gys | Hacker News Reader

Ideally this could switch to ultra-black for the Winter months ;)

There's an old solar heating method that does something similar. Build a large glass box with a wooden frame, and in the middle of that box place a bunch of bricks that have been painted black.

Place an air vent at the bottom and a tube out of the top, and route that tube into your house, and cover the inlet with a heavy sheet of plastic.

Place the entire contraption in the sunniest spot on your property. When the sunlight hits the bricks they will heat up, and the convection will cause an updraft.

Once the updraft pressure is high enough to lift the plastic, it will spray hot air into your home, and when it is too cold the plastic will stop a backdraft from drawing air out of your home.

Additionally, the bricks serve as thermal mass so the heat will continue for several hours after sundown.

You can improve the performance by replacing the open air inlet with a tube that goes to a colder place in your home so that the convection circulates the air in your house.

This is an amazing demonstration of low-technology. Is this documented anywhere with diagrams?

IDK, I read about it in an issue of Mother Earth News I think?

Found one of the ones I've read:

https://www.motherearthnews.com/sustainable-living/renewable...

I recently bought a property that has a cooling system similar to this. The difference in my case is that there are tunnels underneath the foundation containing rocks. Once the temp inside the house reaches a certain point, there are fans that blow the accumulated hot air in the “greenhouse” through those tunnels. It works, but I’m tearing it all out. It’s an eyesore and I rather have proper temp control.

This is the state of the art type of system for greenhouse heat retention, one that I dream of owning. I can't imagine how an underground system would be an eyesore, the ducts going to the roof?

The glass panels lean against the side of the house. It was built in the 80s and wasn't all that well implemented.

I wonder if e-ink technology can scale to large sized roof tiles.

I live in the north and I think it's remarkable that we don't use some form of white/black transitions or convertible awnings etc for regulating temperature.

Black is a better emitter of heat, so if your home is warmer than the surroundings, it will actually make you colder. That said, infrared radiation is a small contributor to cooling at those temperatures, good insulation is the biggest factor by far.

I mean you joke but there's no reason you couldn't.

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