Coway are some of the best, and there are many dumb models without internet access at all
If you don't mind the hum of fans, it's hard to beat a Corsi-Rosenthal box... there are kits from cleanairkits.com or cybernightmarket.com to build quiet PC fan based boxes that in my experience work excellent and can use off-the shelf filters and parts
alt Hacker News
Coway are some of the best, and there are many dumb models without internet access at all
If you don't mind the hum of fans, it's hard to beat a Corsi-Rosenthal box... there are kits from cleanairkits.com or cybernightmarket.com to build quiet PC fan based boxes that in my experience work excellent and can use off-the shelf filters and parts