Topic
3 guides.
On a smoke day, the number that matters is smoke CADR. These certified purifiers deliver the most of it for the money, and the EPA's own research shows what a box fan and four filters can do in a pinch.
The AirVisual Pro's strength is context: it shows your indoor PM2.5 and CO2 next to outdoor air from IQAir's network. Independent field results were more modest than cheaper rivals, and it is pricey.
The PurpleAir Flex is built to hang outside and feed the public PurpleAir map. It is a good outdoor particle sensor with independent test results. For indoor monitoring, PurpleAir points to other models.
