Building a do-it-yourself air purifier is easier than you think

With air quality alerts affecting many midwestern and northern states in the wake of wildfires in Canada, many are searching for ways to make sure they avoid breathing in bad air.

It’s a historically bad situation in some states, with Detroit on Wednesday having the worst air quality in the world, according to airnow.gov.

But as crazy as it sounds, it might be easier than you think to improve air quality intake through building a do-it-yourself air purifier.

Known as the Corsi-Rosenthal box, it pulls air through filters on the sides and blows out clean air. It’s proven to reduce indoor exposure to airborne particles. The box can decrease the levels of particles in the air, such as dust or wildfire smoke.

Adam Simpson, a Michigan resident who was concerned about air quality, decided to build one after hearing about the Corsi-Rosenthal box during the COVID-19 pandemic and how it helped increase air filtration in homes or offices.

Simpson said he woke up in the middle of the night on Wednesday feeling congested and with a small headache, and then noticed his indoor air quality was poor.

He said he remembered the Corsi-Rosenthal box and put one together quickly Wednesday morning.

“Within a few hours I wasn’t as congested, my smart thermostat wasn’t yelling at me and the air in my house was noticeably cleaner,” Simpson said.

Simpson said the total cost of buying materials was $76.72.

“The entire build took about 30 minutes, with a few small breaks to drink some coffee and chat with my wife,” he said.

Here’s how to build your own air purifier

All you need is the following:

• 4 filters, either 3M MPR 1900 (20 x 20 x 1 or 20 x 25 x 1) or MERV 13 (20 x 20 x 2, 20 x 20 x 1, 20 x 25 x 2 or 20 x 25 x 1, 2-inch preferred).
• Lasko or Mainstays 20-inch box fan.
• Scissors.
• Utility knife.
• Duct tape.

Filters can last up to a year, but should be kept away from walls and corners. Here is how to assemble using the above materials.

1. Arrange the filters to create a symmetrical structure, ensuring the arrows are pointed downwards.

2. Duct tape the four edges, with a vertical orientation of pleats preferred.

3. Use one side of the fan’s cardboard box.

4. Cut the cardboard to fit the base of the cube.

5. Duct tape it on all four sides.

6. Place the fan on top of the cube (air must blow upward).

7. Seal all sides, including corners.

8. Ensure any holes on the side of the fan are sealed off with duct tape.

9. Cut the other cardboard sheet to fit the top of the fan.

10. Cut a circular hole (Diameter: 15′ for Lasko and 16′ for Mainstays).

11. Place the shroud on the fan and tape it on all four sides. The shroud increases efficiency and decreases noise level.

To view a video on how to build a Corsi-Rosenthal box on YouTube, watch below.