I normally sleep with the air purifier running. Woke up for WFH, sat in the living room to work, and started sneezing, so I tried measuring the air quality. Oh my god, 43 (that's inside the room) — outside the room, 158. Rushed to turn on the filter plus the expensive fan I'd bought ages ago. If you want an air quality meter, this one runs about 1,4xx baht each.