The DIY box fan air cleaner operates within acceptable thresholds for market safety standard for electric fans, even under extreme conditions.
Advice from Marsh Risk Advisory:
"Corsi Rosenthal boxes are effective in cleaning air inside a classroom."
Any cables that are required to power the fan should be taped to the floor to avoid trips. Other risks include students attempting to touch the spinning fan, but the fans do have covers and this is considerered to be low risk. A study by Underwriters Laboratories (UL) tested box fans with MERV-13 filters attached, finding them to not present a fire hazard even in extreme, modified conditions.
Follow Dr Corsi as he shows you how to build your own powerful air cleaner.
Liesl McConchie successfully got a school wide adoption of filter boxes. These are the documents she developed to communicate with interested parties.
How to set up a University-Wide Corsi-Rosenthal Box Initiative.
Affordable Next-Gen Corsi-Rosenthal Box. 5-10x quieter than HEPA purifiers on full. Quickly clear medium to large rooms. Ultra low power. Order as STEM kit or Fully Assembled
Indoor CO2 concentrations are a proxy to assess building ventilation rates. High CO2 levels represent poor ventilation, indicating that the space does not receive enough outdoor air.
French version of the instructions
Spanish version of the instructions