Dr. Zachary Rubin, a bow tie-wearing allergist with a huge following on TikTok, has created buzz about something called the Corsi-Rosenthal box. He calls it a DIY, cheaper approach to improving indoor air quality. The box is a DIY air filter that costs significantly less than HEPA air filters. The cost difference isn’t really a surprise, but what is a surprise is the box's effectiveness. In fact, it has proved to be more effective in some ways than HEPA filters, reports WebMD. In these times of out-of-control wildfires and poor indoor air quality, an affordable, effective DIY air cleaner seems like a breath of fresh air.
Do DIY Corsi-Rosenthal Boxes Work?
The box is the brainchild of Richard Corsi, PhD, dean of the college of engineering at the University of California-Davis, and Jim Rosenthal, CEO of Tex-Air Filters. The materials and design are simple. They’re so simple that kids are learning to make the boxes for their classrooms. Four filters and a cardboard base make up the box, which is sealed by tape and topped by a fan. The fan pulls in air through the sides of the box and through the filters, then blows it out into the room.
Interest in the device has extended beyond social media. Organizations like the government’s National Oceanic & Atmospheric Administration and the Network for Public Health Law have posted articles about how it works and how to use it.
But the Environmental Protection Agency is encouraging caution. It says homemade air cleaners don't undergo the same level of testing as other cleaners and need more research. The EPA lists caveats about homemade air filters, which would include the Corsi-Rosenthal box.
If you’re interested in making the box yourself, here’s what you’ll need and the steps to take, as outlined by the National Oceanic & Atmospheric Administration:
What you’ll need:
- Scissors or a utility knife
- Duct tape
- 4 MERV 13 or higher 20-inch-by-20-inch air filters (you can also make a mini version)
- A box fan
- Cardboard or the box the fan came in
How to Build a Corsi-Rosenthal Box:
- Duct tape the air filters together to make a cube. Make sure the arrows marked on the edge of the filters are facing the inside of your cube.
- Cut out the bottom of the box your fan came in (or another sheet of cardboard) to fit on the bottom of your cube.
- Tape the cardboard to the bottom of your cube.
- Place your fan on the top of the cube so that the air is blowing up and the cord is going down through the cube.
- Tape the fan onto the cube.
- Use extra cardboard to block any gaps between your fan and your box.