How to build cheap yet efficient wildfire-smoke or Covid air-filter with box fan | Hacker News Reader

How to build cheap yet efficient wildfire-smoke or Covid air-filter with box fan

engineering.ucdavis.edu

3 pointsck22 comments

[PDF] https://aghealth.ucdavis.edu/sites/g/files/dgvnsk261/files/i...

     Materials:
     (1) 20” x 20” box fan
     (4) 20” x 20” x 2” furnace filters MERV-13 / Filtrete™ MPR 1900
     (1) fan shroud made of fan box
     (1) fan bottom made of fan box
     Duct Tape (lots and lots)

> This device with the right fan can deliver 600 to 800 cubic feet per minute.

> And the cost of all the materials for doing this is on the order of about $65.

> So about one-quarter of the cost of a really good HEPA air cleaner to build a Corsi-Rosenthal box, which is more effective than that much more expensive air cleaner.

Not exactly fire/smoke-related, but I did this one year for a remote house that I leave idle 6-months a year and wanted to prevent stagnate air. It did work. The fan energy costs can get excessive, and there are some websites that suggest slower RPM fans what are cheaper.

But the box fans are so ubiquitous. For this year, I settled on adding a timer to the AC line and only run the fan periodically and my energy bill is noticeably lower.

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