Ventilation system CO² [ppm] in your rooms

Hello,

where are you measuring the CO2 content?

A possible cause could also be that due to the room geometry zones arise in which there is hardly any circulation, despite the running controlled residential ventilation. In these zones, however, over a longer period of time, CO2 could relatively accumulate. If you then measure exactly there...

Admittedly not very likely, but 1000 ppm despite air exchange with the outside also seems a bit much to me.

Sorry for the late response.

I have calculated the house volume of the ventilated rooms. Am I only allowed to consider the rooms with supply air or also the exhaust air rooms?

In total, it is 485 m³ of all rooms including supply air and exhaust air rooms; if I exclude the rooms with exhaust air, I come to 300 m³.

Our controlled residential ventilation Vallox 350 provides 350 m³/h. For us, it is also operating at 70% of its capacity, which is noticeable in terms of noise in the utility room.

Could it be that the controlled residential ventilation is too small for our house? It seems strange to me that the controlled residential ventilation is set so high and the ventilation quality is still not satisfactory.

I look forward to feedback on this.

I once calculated the house volume of the ventilated rooms. Am I supposed to consider only the rooms with supply air or also the exhaust air rooms?

The total volume is relevant. It is often designed for 0.5 air changes per hour. In your case, that means a volume flow of 240 m³/h. 70% of 350 m³/h is precisely 245 m³/h, so exactly an air change of 0.5 /h. Sounds good. How many people are there? Can you "calibrate" your measuring device outdoors (i.e., measure)? Have you played around with the CO2 calculator from Niedersachsen?

The air exchange rate is properly designed, but it only "sounds good" if the system isn't already making noise at 70%.

Just a question about that, if the ventilation is designed for the total volume, does the total volume mean the cubic volume calculation of the house? In this case, we would come to 789m³, with an air exchange rate of 0.5 I would still be at just under 400m³.... which ventilation is supposed to achieve that?

Room volume.

Power is not the problem. Then they are no longer small boxes Helios controlled residential ventilation goes up to 2600m2, ceiling units up to 2000m2