Developing and testing low-cost air cleaners for safer spaces during wildfires

• Published in: HVAC&R research Vol. 30; no. 9; pp. 1114 - 1132
• Main Authors: Stinson, Brett W., Gall, Elliott T.
• Format: Journal Article
• Language: English
• Published: Philadelphia Taylor & Francis 20-10-2024; Taylor & Francis Ltd
• Subjects: Air pollution; Air quality; Cardboard; Chambers; Cleaning; Configurations; Constraints; Cotton; Indoor air pollution; Indoor air quality; Outdoor air quality; Particle size; Wildfires
• ISSN: 2374-4731; 2374-474X
• DOI: 10.1080/23744731.2024.2378675

Air cleaning reduces indoor exposure to fine particulate matter (PM
2.5
) during wildfire smoke events. However, resource and cost constraints may limit access to air cleaning during such an event, as both commercial devices and the higher-rated MERV filters that do-it-yourself (DIY) assemblies typically rely upon tend to be expensive and in short supply. With these constraints in mind, we developed and evaluated several configurations of a novel, DIY air cleaner that uses common household fabrics as filtration media. Clean air delivery rates (CADRs) of the devices were experimentally evaluated in two ways: first, with independent measurements of flowrates and single pass removal efficiencies, and second, via pull-down testing in a large chamber. With two layers of cotton batting fabric and a flowrate-increasing cardboard shroud attached, the device achieved particulate matter CADRs of 162, 134, and 206 m
3
/h in 0.02-0.3, 0.3-1, and 1-2.5 µm particle diameter bins, respectively, during chamber testing. Results indicate that these simple, inexpensive, fabric configurations can meaningfully reduce PM
2.5
levels in smaller zones of a home, and thus represent a viable option for improving indoor air quality during rapid-onset air pollution events, such as wildfires.