Ventilation with controlled residential ventilation system

Hello,

a friend said that if you build a Kfw55 house with [Kontrollierte-Wohnraumlüftung], you are no longer allowed to open the windows. Is that true? Is short ventilation still possible? Can you also leave the patio door open for 2-3 hours in summer?

Thanks and regards
Herbert

Hello Herbert,

of course you may. The system will not be damaged by this, you are just negating the advantages of controlled residential ventilation (pollen/dust filtration, possibly cooling, insects, possibly cooling). But basically, there is nothing against turning off the system in summer once in a while (you can also keep it running, but then you unnecessarily consume electricity) and simply open the windows.

Regards,

Sebastian

That means, for short ventilation you don't need to turn it off, but for longer ventilation you have to turn it off?

Thanks and regards
Herbert

You can open the windows in summer and then set the ventilation to minimum. At least that's what I've heard, so no condensate forms in the pipes and causes mold. In summer, you then lack the filtration. In winter, however, you shouldn't open the windows anymore because then you waste energy (heat) without recovery. For example, I have a shock ventilation function for when you do business or something :)

I have, for example, a shock ventilation function,

Thank you for your contribution, how exactly does the shock ventilation function work?

At least with my controlled residential ventilation, this can be realized in different ways: Push buttons or via the control unit. Push buttons in the bathroom, to press while showering or simply for other things. Alternatively or additionally, the system could be automatically controlled by a humidity sensor or a CO2 sensor.