How often you need to change the air filters might depend on the following:
- Air filter model
- Overall indoor air quality
- Quantity of pets
- Household size
- Air pollution levels and construction around the residence
- The MERV Rating
For standard 1"–3" air filters, brands usually tell you to change them every 30–90 days. If someone in your family suffers from light to moderate allergies, you could install a better air filter or change them even more frequently.
The short answer to "how often should I swap my air filter?":
If you don't have a smoker or pets at home, and your filter is the widely sold 1" filter with a MERV rating of 4, you should be able to wait up to 90 days prior to changing it.
What air filter types last longer?
Many air filters are supposed to last up to six months, while others have to be replaced each month. The denser the air filter, the longer it can last. In most cases, you need to look at the thickness of the filter versus the brand. You also need to look at the MERV Rating.
The MERV Rating is a scale that records from 1-20 and assesses how effectively an air filter can pull particles out of 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 can last longer, it may also hamper the flow of air in your home. And you will need to exchange the filter more often. And if you have an older piece of equipment, plan to replace the filter more frequently to extend the life of your filter.
How regularly should I replace my air filter based on thickness?
The lifespan of an air filter also counts on the thickness. A 1" filter will have to be swapped out more often instead of a 4" filter.
- A 1" pleated air filter ought to be exchanged every 30-60 days.
- A 2" pleated air filter ought to be exchanged every 90 days.
- A 3” pleated air filter should be changed out every 4 months.
- A 4" pleated air filter must be exchanged every 6 months.
- A 5” or 6" pleated air filter must be replaced every 9-12 months.
One of the benefits of thicker filters is not only do they live longer, but they also posses a better MERV Rating. This means they can do a more effective job of getting rid of the particles in your home. They also create less air resistance, which can help ones HVAC system operate more efficiently and limit wear and tear on components such as the blower motor.
If you have a whole-home air purifier, you will also need to switch out the filters more often.
How often should I change my air filter if I have a dog or cat?
If you want pets, you might have to replace your air filter more frequently. Pet hair and dander can rapidly clog an air filter and reduce its effectiveness. For every shedding dog you own, expect to switch out the filter a month earlier than you would in a home lacking pets. The same is true of cats, although they tend not to shed as often as dogs. If you own a hypoallergenic or non-shedding dog or cat, you might not need to replace your air filter as frequently.
Although a good rule of thumb, you will need to check the air filter more often to decide if it needs to be exchanged. Dogs usually do not shed the same amount all year. They shed more in the spring and fall when they are blowing their coat. Check the air filter monthly and exchange it when it seems clogged.
Here are averages that can help you understand how often you should get a new air filter at your residence:
- Vacation house or a single occupant and no pets or allergies: every 6–12 months
- Common suburban home without pets: every 3 months
- A single dog or cat: every 60 days
- More than one pet or if anyone has allergies: 20–45 days