Ventilation system CO² [ppm] in your rooms

Hello everyone,

all controlled residential ventilation system owners. Have you ever measured the CO² in ppm in your ventilated rooms out of curiosity?

According to the internet, the values should be below 1000 ppm. 400 ppm is the fresh air outside. Normally, I have around 600 ppm - 700 ppm when no one is in the room. With the number of people present, this value naturally increases.

What I noticed is that in our bedroom at night, the value rises above 1000 ppm, which is actually not so great. I actually thought I installed a controlled residential ventilation system exactly for this reason to always have fresh air.

Therefore, I would be interested in comparison values from you if you have them.

Maybe something is wrong with the system.

Older textbooks write about 300 ppm CO2 in the atmosphere. A few years ago, however, 400 ppm was measured as the average CO2 concentration. My measuring device also always shows values around 400 ppm as a baseline (i.e., empty house, well ventilated). In the inhabited/used house, the normal value here with us is around 500 ppm. In the bedroom (two people), I ran the device twice with data recording. Once on average 600 ppm, once 700 ppm. Maxima each time good 800 ppm. Values over 1000 ppm are only reached during parties, lots of guests. Usually, I then increase ventilation, which helps somewhat (700 ... 800 ... 900 ppm, depending on the number of guests of course) and at some point, you have to open a window.

How strong is the reduction of your controlled residential ventilation at night?
Does the overflow ventilation work properly when the door is closed?

There is no night setback, only an operating mode "Auto," which is probably controlled by the temperature. I didn't quite understand that during commissioning. Typically, we run "reduced ventilation."

We installed "innoperform Überströmdichtungen." That works fine.

Morning, nice that someone can say something about the topic. The controlled residential ventilation is a Vallox and the installer had set a night setback. But I removed this and the controlled residential ventilation now runs at the same level as during the day. Still, at night we get over 1000 ppm. Regarding overflow, I can't tell you anything now. No special measures have been taken except that the door leaf has air at the bottom where air can actually circulate. So you think that the 1000 ppm is definitely too high, right? I mean, if I compare the values with Bieber0815.

The state of Lower Saxony provides a CO2 calculator, which can be found at weh weh weh dot co2-Modell dot nlga dot Niedersachsen dot de. You can play around with it a bit.

There is also something about the classification of the numbers (1000 ppm is not yet a catastrophe).

Why don’t you reveal the volume of your house and the set air exchange rate.