The Mi 3H is a decent model (fairly significant improvement on the earlier models). I have one in my bedroom, and it really only cranks up the volume if I fry s

The Mi 3H is a decent model (fairly significant improvement on the earlier models). I have one in my bedroom, and it really only cranks up the volume if I fry something in the kitchen and forget to run the extractor. VOC levels (as measured by a separate sensor) were up around 400 μg/m^3 when we moved in — somewhat high, probably because the apartment was new — and after a week, during which the Mi 3H was on auto mode and always silent, I tested again and they were down around 120 μg/m^3. It also deals with moderate spikes in PM — like someone smoking on the balcony outside, or opening a dusty moving box in the room — without increasing the noise levels noticeably.