White noise machines are widely used for sound masking, increasing
privacy in offices and helping people sleep. The classic
approach is a fan in a box, though in the past ten years people
have mostly switched over to electronic ones. But a fan is really a
great approach; you just need to put it to better use: have the fan
clean the air. Instead of spinning a fan in free air to make noise, you can have it
pull air through a filter. A small purifier sounds a lot like a
classic noise machine, is only a bit larger and more expensive, and
removes smoke and infectious particles from the air. For example, here's
a $47 purifier with a 6.5" diameter, cleaning 34 cubic
feet of air per minute ("CADR") at 45dB. For most circumstances
where someone would use a white noise machine, this kind of small
purifier is all-around better. Now, 34 CFM is not very much air cleaning. I usually run an AirFanta 3Pro and it cleans ~6x more air for the same amount of noise, or ~12x more
air with much more noise (~56dB). On the other hand it's more
expensive ($165) and bulkier (12.6" square), and arguably uglier. Still, even a 34 CFM purifier helps a lot with smoke. If you have a
10ft square room with an 8ft ceiling and a reasonably typical 0.5 air
changes per hour through leakage from outdoors, this small purifier
will cut particulate levels to 16% of the outdoor level. In AQI terms
(not linear) this is like going from AQI 200 to 72 or AQI 100 to 31. Comment via: facebook , mastodon , bluesky
Air Purifiers as White Noise Machines
Brief
Air purifiers can act as white-noise machines by pulling air through a filter so the fan both masks sound and removes smoke/infectious particles. A $47, 6.5" unit provides 34 CFM (CADR) at 45 dB; an AirFanta 3Pro (~$165, 12.6" square) offers ~6×–12× more CADR depending on noise (~56 dB). A 34 CFM unit can cut room particulates to 16% of outdoor levels.
Why it matters
$47, 6.5" purifier: CADR 34 CFM at 45 dB; in a 10ft×10ft×8ft room with 0.5 ACH leakage it cuts particulates to 16% of outdoor levels (AQI 200→72 or AQI 100→31).
Key details
- AirFanta 3Pro (~$165, 12.6" square) delivers ~6× more CADR than the 34 CFM unit at the same noise or ~12× more at ~56 dB — pricier and bulkier but much higher air cleaning.