Several times a week, the air quality degrades very suddenly. Sometimes I am home, sometimes I am not, sometimes I’m awake and sometimes during the night. Sometimes I’m home for several days and do not leave the apartment much… and the quality stays in the green.

i don’t think the sensor is clogged or working poorly as I have another detector, a small one without any detail from another brand and that is located on the other side of the largest room in my apartment. The second one is not a smart detector, it’s just a light (green/orange/red) so there can’t be any conflict.And the two are usually in agreement over the overall quality.

my place is highly insulated so the indoor temperature is very stable and the heater activity is minimal (I can also see it on my utility bills). I cook but obviously not while I’m not home or while I sleep. I don’t smoke and I don’t use any gaseous products. I use a built in ventilation system (over the stove but also from the building itself) whenever I’m cooking.

unlike other users here, the reading is not blocked at 999 (see screenshots below, two examples among many. On one of these two, I left at least an hour before the spike started). I don’t understand what is causing this.