Is smoke in your home? Here's how to make an air purifier using a box fan
As wildfire smoke impacts air quality across the U.S., experts are providing guidance on building DIY air purifiers using box fans and high-efficiency filters. These measures are intended to help reduce exposure to harmful particulate matter like PM 2.5.
Why it matters
With increasing wildfire frequency, practical health advice for improving indoor air quality is becoming essential for public safety.
A version of this story was originally published on Jan. 10, 2025. It has been updated to reflect the wildfires currently bringing smoke to the U.S.
Interest in air filters and purifiers is spiking as wildfire smoke spreads, including questions about how to build a homemade air purifier.
On Friday, the air in a large section of the U.S. — from Minnesota to Virginia — was listed as "very unhealthy" due to particulate matter from large wildfires, according to the federal AirNow air quality monitor.
The smoke is coming from wildfires in Ontario, Canada, and northern Minnesota — where Duluth and other cities are enduring hazardous air at record levels, as Minnesota Public Radio reports .
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