Use ventilated façade as an additional heating?

Hello everyone,

I have had a vision in my mind for weeks.
The house has a south-facing side, so I looked into warm air collectors. However, I would be reluctant to screw these black things onto my yellow facade. The facade is only plastered, not insulated; 36 cm DDR hollow concrete blocks.
Therefore, I now have the idea to insulate the facade from the outside with wood fibers and then attach black or dark trapezoidal sheet metal at a distance of 10 cm. The air warmed in the intermediate space is then supposed to be blown downwards into a room through an air duct. The incoming air is supposed to come from the same room. Thus, only the inflowing air is heated. The metal sheets are sealed on all outer sides so that no warm air is lost.

Since there are 4 rooms on the front of the house, one could directly heat 4 or only 2 rooms with it.

Can that work? Does it bring any benefit at all? The area would be about 30-35 sqm.
Would it work even with sunlight and some wind? Or does the wind blow the heat away directly?
It is mainly intended to be used in the transitional period to support heating.

Regards, Sebastian

Interesting idea. However, warm air rises upwards. The blower also requires electricity. The investment and operation costs will significantly exceed the heating costs. The whole thing will probably only work within a small temperature and weather window. A ventilated facade is for insulation, not for heating. In summer, it will get extremely warm behind your black sheet metal. Insulation won’t help in the long run and your house will get warm. Then you can start thinking about an air conditioner... So rather pointless.

All right, thanks for the quick response. The fan should run on a small solar panel. So completely autonomous and off the house power grid.

In the Allgäu, a hay drying system operates on this principle, with an additional wood chip heating system. There is a report about it on Youtube (Heutrocknung Berghof Babel). Here you can take a look at the principle, and manufacturers are also mentioned. Whether this makes sense for a residential building, I do not know.

The principle generally works. But simply hanging metal sheets in front of the facade does not work. Take a look at the Bio-Solar-Haus based on the house-in-house principle. They build houses exactly according to the principle you have in mind. The basis is, on one hand, the warming of air in the cavity of the suspended facade and, on the other hand, the heating through an otherwise unheated winter garden with a high glass proportion. The whole thing can also be retrofitted as part of a renovation, but the effort is not insignificant. In summer, the house is also no longer heated up because ventilation openings at the eaves or gable side release the warm air when outside temperatures are higher. You can push this to the extreme with the house in the greenhouse or with a full-surface double facade including the roof. There are interesting videos about both on Youtube.

Right, I have already seen the greenhouse thing on TV. They basically live in a greenhouse that regulates its own climate. But for me, it’s still too exposed… then the neighbors always have a lot to see ;-)

First of all, I want to thank you for the kind replies. Let’s see if and what I do in this direction. The great green government is pushing everything at the moment, but without thinking it through and then changes its mind again. What is right and great today is already wrong tomorrow and has to be replaced. As far as heating technology is concerned, I will initially wait out the situation with my oil heating and run the thing into the ground.