How often you need to exchange your air filters could be on the following:
- Air filter model
- Overall indoor air quality
- Quantity of pets
- Household size
- Air pollution levels and construction nearby the residence
- The MERV Rating
For standard 1"–3" air filters, brands typically instruct you to change them every 30–90 days. If you suffer from light to moderate allergies, you can use a better air filter or change them even more regularly.
The shortest answer to "how often should I exchange the air filter?":
If you don't have a smoker or pets in your home, and your 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 survive longer?
A few air filters are manufactured to last up to six months, while others need to be swapped monthly. The thicker the air filter, the longer it will last. In general, you can check the thickness of the filter instead of the brand. You also need to check at the MERV Rating.
The MERV Rating is a scale that records from 1-20 and assesses how efficiently an air filter can remove 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 should last longer, it might also impede the flow of air in your home. And you will have to change the filter more regularly. And if you have an older system, plan to substitute the filter more regularly to extend the life of your filter.
How often do I need to switch out my air filter based on thickness?
The longevity of an air filter also counts on the thickness. A 1" filter will need to be changed out more often compared to a 4" filter.
- A 1" pleated air filter ought to be replaced every 30-60 days.
- A 2" pleated air filter should be exchanged every 90 days.
- A 3” pleated air filter should be replaced every 4 months.
- A 4" pleated air filter must be swapped out every 6 months.
- A 5” or 6" pleated air filter ought to be changed out every 9-12 months.
One of the perks of thicker filters is not only do they last longer, but they also provide a higher MERV Rating. This means they will do a better job of eliminating the particles inside your home. They also create less air resistance, which can help your HVAC system operate more efficiently and reduce strain on components such as the blower motor.
If you own a whole-home air purifier, you will also have to exchange the filters more frequently.
How regularly should I exchange my air filter if I own a dog or cat?
If you want pets, you might need to exchange your air filter more frequently. Pet hair and dander can quickly clog an air filter and limit its effectiveness. For each shedding dog you have, expect to change out the filter a month sooner than you would in a home lacking 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 have to switch out your air filter as much.
Even though it's a good rule of thumb, you will need to examine your air filter more frequently to determine if it should be swapped out. Dogs tend not to shed at the same rate year-round. They shed more in the spring and fall when they are blowing their coat. Check the air filter each month and change it when it seems clogged.
Here are averages that can help you recognize how frequently you should install 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 90 days
- One dog or cat: every 2 months
- More than one pet or if someone has allergies: 20–45 days