tldr; DIY option. Box fan + MERV-13 filters. ~$70 to build. Surprisingly effective but loud and bulky.
Check pricesScores based on sentiment analysis of topic-related comments
Best praise vs top criticism for Corsi-Rosenthal Box
“Always cool to see Corsi-Rosenthal setups. Nice work. Curious how the duct fan compares to a normal box fan”
“I second this. I found Levoit and Coway the worst for off-gassing smells. 1 of my Winix had a mild smell but it did dissipate quickly. However, in the next few months I plan to replace all 3 Winix purifiers with DIY Corsi-Rosenthal box purifiers. Much easier to control the materials!”
701 Reddit opinions analyzed • Last updated 2/24/2026