HOW TO DIY LIKE A PRO: The Home Air Filter Hack You Need for Next Fire Season

Last summer, my daughter, Monica, called me in a panic from her home in Napa, California. Wildfires were raging through the state, and she was struggling with smoke entering her house. For the first three weeks, the wind had been on her side, but after that, it was funneling dirty air directly into her community.

Monica’s house was full of smoke, and air filters were almost completely sold out in her area. I could only find one locally, and it would have cost $500 after shipping. I was still determined to find a solution that would work for her without spending an arm and a leg.

While going through my files, I remembered that many years ago, a friend of mine from China had developed an inexpensive, DIY air filter to deal with the pollution in his country. It helped building occupants clear their air for a fraction of the cost of a traditional purifier. I dug up the references, sent the design to Monica, and she tried it out. The DIY filter worked! In fact, it worked so well that I thought I’d share it with you today.

The premise is simple: By attaching a high efficiency pleater air filter to a box fan, you can create a basic air purifier cheaply and easily. When I looked the idea up on YouTube, I found multiple ways to make the device. Some people, like my friend in China, just tape the filter onto the frame of the fan using duct tape (the filter should go onto the suction, not discharge, side of the fan). Others will attach clamps to the side of the fan housing and just “clip” the air filter onto the fan.

Whichever method you choose, as long as you have a quality filter with a minimum efficiency reporting value (MERV) rating of four or higher, you should be able to remove up to 97% of the pollen, dust, and smoke in your home’s air. It worked for my daughter, who made three effective fan/filter sets for under $100.

To learn more about this method, visit SmartAirFilters.com/en/about/our-story or search “DIY Air Filter” on YouTube. I wouldn’t recommend using this hack to purify your building permanently, but it works fantastically for smaller areas in a pinch!