When HN users recommended it
1 HN user recommended this in 2014, in one comment.
20072026
Each tall tick is one HN user's first recommendation. A short tick is the same user again. Click a tick to jump to the comment.
1 HN user recommended this in 2014, in one comment.
Each tall tick is one HN user's first recommendation. A short tick is the same user again. Click a tick to jump to the comment.
> At least some of the expensive filters have activated charcoal
Activated carbon is effective just to remove odors and nothing more. It's not expensive either, it's like $ 10/kg retail.
A high-end filter is more likely to work with ionization. [1]
[1] http://www.amazon.com/Sharp-FPA80UW-Plasmacluster-Purifier-F...