How Often to Change Air Filters for Better Air Quality and Energy Efficiency

Some home tasks tend to slip through the cracks—until you realize they’re way overdue. Changing your home’s air conditioner filters is likely one of those tasks. Understanding how often to change your air filters is essential for a healthy, well-functioning home. 

To better maintain your HVAC efficiency and the air quality in your space, add this task to your regular routine and heed these helpful tips when the time comes.

Why You Need to Change Your Air Filters Regularly

Located inside your air vents (or inside the HVAC unit itself) are filters that help regulate and refine air quality. They trap airborne particles like dust, pollen, pet dander, and mold spores before they get a chance to circulate. Overtime, the filter can become clogged with these contaminants. And, once clogged, it can’t trap anything else—meaning those irritants circulate right back into your living space.

A clogged filter makes your HVAC system work harder, which uses more energy and shortens the lifespan of your equipment. A clean filter keeps things running smoothly (and can even reduce your utility bills).

Don't Miss

How Often Should You Vacuum the Carpet? Here's Martha's Recommendation

Will Reversing Your Ceiling Fan Actually Save You Money This Winter?

How Often to Change Your Air Filters

At the very minimum, your air filters should be swapped out every 90 days. "There is a rule of thumb that both manufacturers and tradesmen like myself like to say," shares Brandon Dolan of Dolan Inc. a plumbing, heating, cooling, and electric company. "90 days or three months minimum."

However, more frequent replacements are usually recommended. "We recommend once a month, especially in the seasons where it is super hot or super cold," says Dolan. "The system is working hard enough during those peak times, and you can assist the system by being proactive with the filter replacement."

There are several factors that come into play when determining your air filters' specific replacement cycle. "First, take into account if you have any pets. Pet hair and what they bring in from outside are certainly a factor," says Dolan. "Next is how many people live in the house. If there is more than four individuals living in one house with one HVAC unit, skin, hair, and dust can accumulate very fast."

Finally, you also need to take into account the specific HVAC system you have installed. "Basic systems take ordinary-sized air filters, but certain systems can have electronic air cleaners or a more sophisticated filtered system," adds Dolan.

How to Change HVAC Air Filters

1. Turn Off the HVAC System: As a safety precaution and to prevent unfiltered air from circulating, shut off the system while you’re working.
2. Locate the Filter and Remove Cover: Most air filters are behind return vents or inside the HVAC system itself. (Check your manual if you’re not sure.) Manually remove the vent or cover. Make note of the size and dimensions of the old air filter, ensuring that your new model matches.
3. Remove the Old Filter: Gently slide out the old filter, placing it directly into a trash bag to prevent dust from flying about.
4. Insert the New Filter: It should slide in snugly. Be on the lookout for arrows that direct which side goes up.
5. Return the Vent or Cover: Replace the air vent or the unit’s cover. Resume HVAC use.

Air Filter Maintenance Tips

Air filter changes are simple, but it’s the remembering to do it that trips most people up. Try setting a recurring calendar reminder, treating home maintenance tasks like you would a haircut or dentist appointment. When you change the filter, place a sticky note near the unit (or in an inconspicuous spot near the vents themselves) with the date, so you’re never left wondering when you last tackled the task.