Window rebate ventilator - Good idea for uninsulated old buildings?

We will also install a fan in the bathroom, but it is not absolutely necessary for RegelAir.

We will also install a fan in the bathroom, but it is not absolutely necessary with RegelAir.

Yeah, but if you want a significant air exchange, that's recommended, isn't it?

Ventilation systems have only the advantage of heat recovery. Computationally probably a zero-sum game. Both have advantages and disadvantages. The "Bayernlüfter" are supposed to be good. But I don't really know if they are actually any good.

Thank you first of all for your responses. I have now ordered four pieces for two windows and will test it. Cost is 37€, which is okay. As I said, I am aware that I cannot completely avoid airing with this, but if I can reduce airing because of it, that would be very good. Regards Specki

I would be surprised now - we have those things in every window and three active fans as well. And that’s just about enough so you don’t need to ventilate anymore.

But I’m curious how it behaves in your old building and hope to hear from you soon! And gladly also photos of the parts and the installation...

Tell me more about your fans. Which ones and where are they installed.