After reading this article when it was posted in 2022 and the author's other post on particulates[0] I bought the sqair[1], which we are very happy with. Allergies and morning congestion are nearly 0 after using it. We live on a very busy road so I run it all the time and with the carbon filter as well. I would like to get a second one eventually -- it only cleans 430 sqft of air and our condo is 730.

[0]: https://dynomight.net/air/#things-that-create-particles-indo...

[1]: https://smartairfilters.com/en/product/sqair-air-purifier/