When HN users recommended it
1 HN user recommended this in 2019, 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.
Purifier Display Formaldehyde Sterilization Cleaning
Amazon's catalog no longer lists this product (checked 2026-11-02). The name comes from the link HN users posted.
Its not difficult, firstly buy a monitor which tracks CO2, PM2.5, VOC:
https://www.aliexpress.com/item/32887570197.html?spm=a2g0s.9...
Tracking CO2 is very useful for internal spaces.
And an Air purifier: https://www.amazon.com/Purifier-Display-Formaldehyde-Sterili...