Outside, air quality was 300-1100 (off-the-scale and very hazardous) with smoke hanging in the air like dense fog. Inside, the indoor air quality monitor says the air is very clean (AQI 23). This is with running the furnace fan continuously and changing filters every 3-4 weeks. The only downside is the smart filter feature doesn't actually know when the filters are dirty, only how much air volume has gone through them.