Decentralized vs. Central Controlled Residential Ventilation? Points for KfW House Calculation

Hi Mirage, one more small but possibly crucial remark: According to DIN, airtight houses must/should be ventilated 12 times a day! The value is probably the upper limit and the optimum; twice a day a little is certainly too little. Perhaps existing experts can provide a realistic value? Best regards Peter

... According to DIN, one must/should ventilate airtight houses 12 times a day!

Which DIN?

Best regards.

Tomorrow dear people,

I am happy about your active participation. Uff, airing the room 12 times a day and then also shock - cross-ventilation, I honestly can't manage that. Twice a day will already be really difficult...

Edit:
I still have the question of whether a controlled residential ventilation with WRG plays a role in the energy calculation.

Which DIN?

v.g.

"In living rooms, an air change rate of 0.5/h (DIN 4108-2 from 2011, section 4.2.3) is required. If there are no noticeable odors in the apartment, insufficient air exchange often manifests itself through excessively high humidity" (Wikipedia).

0.5/h corresponds to 12 complete air changes per day.

Best regards

... does anyone have any idea about the calculation of the air exchange rate? On the one hand, air quality is of interest, on the other hand - especially for the house (mold) - the humidity. Humidity and poor air quality almost only occur when people are present, right? That you should ventilate the house just as often when absent/on vacation etc. as when present seems rather illogical to me at first glance! Are there any opinions on this?

...I still have the question whether a controlled residential ventilation system with heat recovery plays a role in the energy calculation.

Of course! It is not for nothing that the thermally effective air volume flows have to be taken into account, for example in the heating load calculation. The better a building is insulated, the more noticeable and sustainable the influence of heat recovery.

Regards.