DIY Corsi-Rosenthal Boxes

Published

December 22, 2024

The Corsi-Rosenthal Box is a DIY air-filter made from a box fan and MERV 13 air filters. This project is primarily a summary of references I’ve collected and information I’ve documented in the construction of my boxes.

Box Fans

This is the first box, built around December 2021 and rebuilt in September 2022 with new filters. Figure 2 shows the difference between a new and used filter.

This original box was largely used in an open basement. The box fan is a 20in. Hurricane which works well because the control is accessible, but it is louder than I’d like. The filters are 3M Filtrete 1900.

My original CR Box

Rebuilt CR box with new filters
Figure 1: CR filter after 8 months of use.
Figure 2: Comparison of New/Used filters

Honeywell TurboForce

I built another box using a Honeywell Turbo Force 908 fan. This set up is much more quiet than the Hurricane box filter. This filter is also built with 20x20x2 and 20x16x2 MERV-13 filter instead of the 1in deep used previously.

Figure 3: Honeywell Turbo Force Filter

This is a slightly different version using 4 20x16x2 MERV-13 filters.

Figure 4: Honeywell Turbo Force 4 20x16x2