Air exchange rates and air quality - understanding

Moreover, the outdoor air CO2 levels differ regionally. It makes a difference whether you live in Frankfurt or at 1500m in a mountain village.

It would be interesting to install a VOC sensor in addition to the CO2 sensor. It measures several gases, such as adhesives from materials, cleaning agents, cigarette smoke, food odors, and many other gases that can cause headaches and migraines.

It just dawned on me...

My wife has been struggling with migraines more frequently for a few weeks now.
She never had any problems with them in the 29 years before!

Could it be that the newly (April 2020) installed, fully glued, vinyl flooring is off-gassing due to the activation of the underfloor heating and thus causing the migraines?

The VOC sensor only detects so-called volatile gases. This ranges from perfume to adhesive, which is quite a broad spectrum. Therefore, there is no unit like "ppm" for CO2. Your wife's migraine could be caused by the adhesives in the vinyl but does not have to be.

Here is an example from practice:
At a hotel reception, the employees complained about constant headaches. A VOC sensor detected elevated values there. A CO2 sensor showed completely normal values. In the end, it was found that behind the reception desk a cork wall with a total of 20 sqm had been glued as a decorative element. When the cork wall was removed, the headaches also disappeared or were only caused by the guests.

Interesting!

So if you put such a VOC measuring device (Can a private person buy something like this cheaply?!) in the bedroom, you could for example observe whether the value decreases when airing out and rises again after closing the windows, right?

Our Q350 runs continuously in automatic mode at level 2 with 175m³/h.
The volume of the individual levels can be set independently during installation (or by the installer).

When we shower, the system automatically (there is a function in the menu) switches up to level 3 until the humidity value is appropriate again. I estimate this takes about 30 minutes.

We are actually satisfied with our air quality. I have not noticed anything negative yet. However, I have never set up a measuring device.

Same here

, , could you tell me what this function is called? I haven’t checked the device itself yet, but in the iOS app I can’t find a corresponding option for our Q450 with enthalpy heat exchanger.