The Best Methods To Filter Indoor Air, According To A Pollution Expert At CU Boulder

BOULDER, Colo. (CBS4) – With much of the state still under an Air Quality Alert largely due to smoke from western wildfires, doctors suggest staying inside and filtering your indoor air. An expert on air cleaning from the University of Colorado Boulder showed CBS4 how it can be done effectively and affordably.

"You may not be able to tell the difference today or tomorrow in your quality of life, but it could make a big difference over the course of your lifetime if you protect yourself from air pollution," said Dr. Marina Vance, an assistant professor of mechanical engineering and environmental engineering at CU Boulder.

For years, Vance has researched indoor air pollution at the experimental air quality lab on the CU Boulder campus. One of her main focuses is particulate matter that comes from everyday sources.

"In the context of wildfires and the air pollution that we're having in the Front Range, we really care about particulate matter and ozone," Vance said.

According to Vance, even well-sealed homes with good HVAC systems can still allow some of those particulates inside, so air cleaning can offer another level of protection. In her research she's found there are a myriad of good options, including commercial devices that cost hundreds or thousands of dollars and homemade contraptions.

"Any solution to air filtration is going to be better than no solution but the quality of these are also going to vary greatly," she said.

Vance has found the combination of box fans and air filters with a MERV rating of 13 or higher can provide some filtration in smaller spaces. The cheapest option she suggests includes taping a filter directly onto the intake side of a box fan. A slightly more efficient and expensive option includes forming a cube around the fan with three filters and a cardboard square.

"Because there's much higher surface area, there's lower air resistance, so you're going to have a higher flow rate of air coming through," Vance said.

Vance cautions people to not get a false sense of security when using a DIY air cleaner. While they can provide some degree of protection, it's often relative to the space you put it in.

"It's a small system that will work for a small space. If you put this in a big house, you're not going to be cleaning the air of the entire house," she said.

Ultimately, cleaning can make a difference, especially as the problem of poor air quality isn't going away.

"The unfortunate truth is that we're going to be needing systems like this more and more in the future," Vance said.

Vance's lab was just awarded a grant from the Environmental Protection Agency (EPA) to test low-cost options for people looking for protection during wildfires. The study is expected start in September and will last three years.