You Probably Should Change Your Home’s HVAC Filter Right Now

Changing the filter for your home’s heating, ventilation and air conditioning system, or HVAC, is one of those tasks you probably forget to do as often as you should. Some people may even be unaware that they have an HVAC filter that needs to be changed. And it’s a really important item to swap out.

In fact, the University of Rochester Medical Center reports that indoor air can actually cause health issues because it’s often so polluted. The central air conditioning or heating system in a typical modern home has an HVAC filter that helps keep the air clean. It can filter out pet dander, seasonal allergens, dust and even virus particles.

So as we trudge through a fall when flu, COVID-19 and RSV are all rampant, it’s even more important to make sure your home is filled with fresh and clean air. Here’s when you should change your HVAC filter and why it’s so important to do so to help stop the spread of viruses.

Good air filtration helps reduce toxins in the air.

“Indoor air quality is very important for [your] quality of life and health and well-being,” said Dr. Mark Loafman, a family medicine doctor at Cook County Health in Chicago. “And the filters we have on our HVAC systems are the prime and oftentimes the only source of air cleaning we have access to.”

Your air filter helps make sure the circulating air in your home is clean so your HVAC system isn’t simply pushing through contaminated air over and over. This is particularly important during times of high virus spread ― like right now.

We learned from COVID-19 that virus-containing droplets can hang in the air for a long time, Loafman noted. This makes it all the more important to think about the quality of the air we’re breathing, whether that is at home, at a restaurant or on an airplane.

An HVAC filter can help pull those droplets from the air before infecting someone else, Loafman said, although he cautioned that people should also take other precautions to prevent the spread of viruses.

Your HVAC filter circulates your home’s air and catches particles.

In order for your HVAC filter to clean the air properly, you need to make sure the filters aren’t full of already-collected particles and dust.

Additionally, certain filters are designed to capture smaller particles, according to the United States Environmental Protection Agency. Filters have a rating ― known as a minimum efficiency reporting values, or MERV, rating ― based on the size of the particles they can capture.

The higher a filter’s MERV rating, the smaller the particles it can catch. Filters can catch particles that are between 0.3 and 10 microns, according to the EPA.

For reference, a study found that virus droplets 2 microns in size lingered in the air for minutes after leaving an infected person’s system. Some experts recommend getting a MERV 13 as the minimum rating for home use.

You should switch out your HVAC filter regularly.

To make sure your heating and cooling system is working efficiently, and that the filter is doing its job, you should change your HVAC filter regularly. The recommendations differ depending on the filter, but a good rule of thumb is every 60 to 90 days, according to the EPA.

“The better the filter, the quicker it’s going to clog and need to be changed,” Loafman said. “Erring on the side of more frequent as opposed to less frequent changing is a good idea.”

You’ll quickly be able to tell what a dirty HVAC filter looks like — it’s generally covered in dust, hair and is brown in color. Unused HVAC filters are white.

While this can help lessen the amount of virus in a home, other preventive measures need to be followed.

Changing your HVAC filter is only one piece of the virus-prevention puzzle.

“These are not a replacement for the other strategies,” Loafman said. You still need to make sure you are up-to-date on vaccinations for the flu and COVID-19, wash your hands, isolate if you’re sick and wear a mask in crowded spaces.