Work

Not all boxes are equal: Investigation of parameters affecting PM2.5 particle removal by the Corsi-Rosenthal box

Year: 2025

Type: article

Abstract: The Corsi-Rosenthal (C-R) Box has gained widespread popularity as an affordable, do-it-yourself air cleaner designed to improve indoor air quality. Despite its rapid adoption, limited studies have evaluated how different operational and experimental variables affect the C-R box’s efficiency. This study investigated the Clean Air Delivery Rate (CADR) of the C-R box as a function of filter rating, its electret enhancement, measurement interval, location, and type of measurement devices, and additional air mixing when removing PM2.5 sodium chloride (NaCl) or Arizona Road Dust (ARD) particles in a 3,024 ft3 (~86 m3) room. Based on measurements by a research-grade MiniWRAS (1371, DURAG Group, Hamburg, Germany), the C-R box with four 2-inch MERV-13 filters achieved a CADR of 358.56 ± 10.58 cubic feet per minute (cfm) at its highest fan speed, outperforming MERV-8 filters (209.93 ± 9.30 cfm) by 71% despite only a 41% increase in filter cost. MERV-13 filters with an electret designation did not improve CADR compared to plain MERV-13 filters. When challenged with ARD particles, the C-R box achieved a CADR of 416.60 ± 8.31 cfm: 15% higher compared to NaCl particles. We also observed that moving the C-R box farther away from the measurement devices (140 inches vs 65 inches) led to a decrease in CADR by ~8%. However, using additional mixing fans helped improve CADR in the room’s corners by up to 21%. Comparison of CADR determined by an out-of-the-box consumer-grade AirVisual monitor with MiniWRAS showed that the AirVisual yielded the same trends, albeit at a ~14% higher CADR. Our investigation of variables affecting the measured C-R box’s CADR will help optimize its performance and improve data comparison across studies. We also demonstrate that consumer-grade monitors are a viable option in investigating the performance of air cleaners, especially their localized performance.

Source: Journal of Aerosol Science

DOI: 10.1016/j.jaerosci.2025.106731

Authors: Antonio Baratta, Taewon T. Han, Gediminas Mainelis

Institution: Rutgers, The State University of New Jersey

Language: English

Topic: Aerosol Filtration and Electrostatic Precipitation

Subfield: Electrical and Electronic Engineering

Field: Engineering

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $2,850

Funders: U.S. Department of Agriculture, National Institute of Food and Agriculture