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TikToker shares hack for building a cheap, homemade air filter to combat wildfire smoke: 'This saved our lives 2 summers ago'

You don't need a ton of stuff to create this simple, effective air filter.

Corsi-Rosenthal Box

Photo Credit: TikTok

Home air purifiers and cleaners are in high demand as thick clouds of smoke have made their way down from Canada due to the hundreds of wildfires currently raging there.

But as many people are finding out, these air cleaners can be extremely expensive, as many of them cost several hundred dollars.

No one should have to suffer financially to afford clean air. And luckily, one TikToker, named Nina (@strawberry.road), is solving that problem by showing viewers how she made her own DIY air filter for under $100. 

@strawberry.road Replying to @ronni6836 the Corsi Rosenthal box can do an air change in a 2500 sq ft space every 20 minutes. improve the air quality in shared spaces with this homemade method for under $100. 🌬 #CorsiRosenthalBox #AirFilter #AirFilterChange #CleanTheAir #CleaningTips ♬ original sound - strawberry.road

The DIY filter in the video is called a Corsi-Rosenthal box, which uses a box fan as a base and represents a cost-effective solution to poor air quality. 

According to Nina, the Corsi-Rosenthal filter can clean the air in "a 2,500 square foot space every 20 minutes."

What you need to build your own Corsi-Rosenthal box

You don't need a ton of stuff to create this simple but effective air filter. The base of it will be a box fan (a 20-inch fan is perfect). Make sure you save the cardboard box the fan came in.

Next, you'll need four filters to attach to the sides of the box fan — here, MERV-13 air filters will work best. Make sure they're 20-by-20-inch filters so that they'll fit nicely on the box fan.

As long as you have some duct tape and scissors at home, that's all you need to buy.

How to build a Corsi-Rosenthal box

While Nina's video highlights how this filter helped her personally, Yale Climate Connections shared even more specific instructions on creating one.

After gathering your supplies, the next step is to tape the four filters together, creating a cube shape with no top or bottom. Notably, the filters will have arrows on them, and each arrow must point toward the cube's center. Ensure the corners are fully taped over so air is forced through the box fan.

The next step, according to Yale CC, uses the cardboard box the fan came in. Cut out one side and tape it to the bottom of your cube. Seal it with tape along the edges.

After this, you'll place the box fan at the top of the cube (so air is blowing upward). Attach it with tape and make sure air isn't escaping from the corners. You can tape more cardboard to the corners to ensure a tight seal if you need to. And that's all it takes. 

What people are saying

Commenters on TikTok were wildly supportive of the shared hack

One user happily wrote, "This saved our lives two summers ago during the wildfires. The filters were BLACK after 1 day."

Another commented, "Epidemiologist approved!" 

Other TikTokers in the comments section discussed how these boxes can also be used for dust, pollen, allergens, and even airborne viruses.

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