I don't really know, and I don't speak from first-hand experience. But from what I've heard, the main concern is not air quality, but humidity. When you heat up

I don't really know, and I don't speak from first-hand experience. But from what I've heard, the main concern is not air quality, but humidity. When you heat up air, its relative humidity goes down. So especially in winter, the ventilation system can blow very dry air into the building. There are simple technical solutions that artificially "humidify" the air, but it's definitely something to look out for. Low humidity can cause all sorts of health problems.