District heating KfW55 - KfW70 costs Ventilation system/Exhaust system

Ohh, Persian... Your German is clearly better than my Persian.[emoji1] I am satisfied with those things. Good enough for us, misuse impossible since there is nothing to operate, no germs, no pipes, nothing to maintain. Simply put. Karsten

Is a thermal bridge possible there? Does air pass through when the fan in the bathroom is running and creates negative pressure in the house, right?

Ohh, Persian... Your German is clearly better than my Persian.[emoji1] I'm satisfied with these things. Good enough for us, misuse impossible since there is nothing to operate, no germs, no pipes, nothing to maintain. Simple indeed. Karsten

One fan per window, I read somewhere you should have at least 2 per window.

First. Because it is cheaper. Second, because it is technically simple and therefore less prone to failure. Third, because keep it simple is a mindset that many people appreciate. (You can drive a Tesla or a Dacia, who is ultimately more ecological from production to the scrapyard is not determined).
About arifas.
In our bathroom we have installed an exhaust fan from the brand Helios, variable speed, with humidity detection and filter insert. In addition, each window of the house has a rebate ventilator from the company Regel Air. That’s all.

Karsten

Thank you!

Our second car is a Dacia 7-seater [emoji23]. I love that thing. It drives, has space, and costs a fraction of the price compared to other 7-seaters [emoji56].

We currently also have these rebate ventilators in the offer. And there is a fan planned in the main bathroom. I am just considering whether a decentralized ventilation system for the bedrooms and bathrooms would be more sensible. A central one will probably be too expensive. I don’t know the window rebate ventilators at all and don’t know if they do what they promise. But decentralized ventilation in the bedroom with HRV might be too loud?!

There is also some mixing here. The central systems (=high investment) exist with and without heat recovery, and the question of why no heat recovery is very legitimate. It’s not rocket science but purely mechanical. It also hardly costs more in terms of investment. The heat recovery easily compensates for the electricity costs, but not so much for the investment. The thing is comfort. Decentralized devices may be perceived as ugly, often described as loud. However, they cost about half as much as a central system altogether.

...and if the system also has moisture recovery, nothing stands in the way of a healthy and energy-saving indoor climate.

That it is more expensive goes without saying, but it is consistently implemented!

The alternative is pure window ventilation without a ventilation system and window rebate vents, which I recommend when architects advise builders to save on construction costs and propose half-baked ventilation concepts.

Window ventilation has worked for decades and if done consistently, no mold will develop.