DIY Portable Air Filter
A Corsi-Rosenthal box is a very simple and inexpensive DIY portable air filter that became popular during the pandemic, but the concept has been around a long time. They can be a good alternative to more expensive/proprietary portable HEPA filter units (also commonly known as ‘air purifiers’).
Making your own Corsi-Rosenthal air filter is pretty simple (a little kid could do it) and replacement filters are relatively inexpensive.
See Wikipedia for more basic info and search online for design options.
Also see my other blogs on indoor air quality and residential HVAC ventilation units.
My Air Filter Design
The basic version I made, after reading the Corsi Foundation’s guide and watching this video and others:
- Four 20″x20″x1″ 3M Filtrete 1500 filters (MERV 12). I got two 2 packs at around $30/pack. Then later I saw much higher rated Filtrete’s in a 4 pack at Costco for much less. Oh well. Shop around! NordicPure 2″ thick filters with higher MERV ratings are also common.
- 20″ Lasko fan (these are just over $20)
- White duct tape (I also hear gaffer’s tape works well)
I think the total cost was around $85. Replacement costs will depend on how much we run the filter and how much I’m able to keep…
