How often you have to change the air filters might depend on the following:
- Air filter model
- Total indoor air quality
- Number of pets
- Household size
- Air pollution levels and construction surrounding the residence
- Your MERV Rating
For basic 1"–3" air filters, companies normally tell you to swap them every 30–90 days. If you suffer from mild to moderate allergies, you could put in a better air filter or replace them even more frequently.
The short answer to "how frequently do I have to change my air filter?":
If there isn't a smoker or pets in the home, and the filter is the often sold 1" filter with a MERV rating of 4, you should be able to wait up to 90 days before replacing it.
What air filter models last longer?
Many air filters are designed to survive up to six months, while others have to be swapped monthly. The thicker the air filter, the longer it should last. Overall, you should look at the thickness of the filter rather than the brand. You also need to consider at the MERV Rating.
The MERV Rating is a scale that stretches from 1-20 and calculates how well an air filter can eliminate particles from the air. The bigger the MERV Rating, the smaller the particle that will be captured by the air filter.
While a filter with a higher MERV Rating might last longer, it can also interfere with the circulation in your home. And you will have to change the filter more frequently. And if you own an older piece of equipment, plan to replace the filter more often to extend the quality of your filter.
How often do I have to switch out my air filter based on thickness?
The longevity of an air filter also counts on its thickness. A 1" filter will need to be exchanged more often versus a 4" filter.
- A 1" pleated air filter ought to be changed out every 30-60 days.
- A 2" pleated air filter should be switched every 90 days.
- A 3” pleated air filter ought to be changed out every 4 months.
- A 4" pleated air filter should be exchanged every 6 months.
- A 5” or 6" pleated air filter must be changed out every 9-12 months.
One of the perks of thicker filters is not only do they survive longer, but they also boast a higher MERV Rating. This means they will do a more effective job of filtering out the particles in your home. They also produce less air resistance, which can help ones HVAC system work more effectively and cut down on wear and tear on components like the blower motor.
If you have a whole-home air purifier, you will also have to exchange the filters more frequently.
How regularly should I change my air filter if I want a dog or cat?
If you have pets, you might have to replace your air filter more frequently. Pet hair and dander can easily clog an air filter and limit its effectiveness. For every shedding dog you want, expect to switch out the filter a month sooner than you would with a home with no pets. The same applies to cats, although they don't shed as often as dogs. If you want a hypoallergenic or non-shedding dog or cat, you might not need to exchange your air filter as frequently.
Even though it's a good rule of thumb, you will need to check your air filter more frequently to determine if it has to be swapped out. Dogs usually do not shed the same amount all year. They shed more in the spring and fall when they are blowing their coat. Inspect the air filter each month and change it when it appears clogged.
Here are averages that can help you understand how regularly you should put in a new air filter at your residence:
- Vacation house or one occupant and no pets or allergies: every 6–12 months
- Average suburban home without pets: every 90 days
- One dog or cat: every 2 months
- More than one pet or if someone has allergies: 20–45 days