How often you need to exchange your air filters might rely on the following:
- Air filter type
- 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 typically ask you to exchange them every 30–90 days. If someone in your family suffers from mild to moderate allergies, you can install a better air filter or exchange them even more frequently.
The quick answer to "how often do I have to switch out my air filter?":
If you don't have a smoker or pets in your 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 prior to changing it.
What air filter brands last longer?
Many air filters are supposed to last up to six months, while others need to be swapped each month. The larger the air filter, the longer it should last. Overall, you can look at the thickness of the filter instead of the brand. You also need to look at the MERV Rating.
The MERV Rating is a scale that stretches from 1-20 and assesses how well an air filter will pull particles from the air. The higher the MERV Rating, the smaller the particle that can be caught by the air filter.
While a filter with a higher MERV Rating should last longer, it could also impede the ventilation in your home. And you will need to replace the filter more regularly. And if you own an older system, plan to switch out the filter more regularly to preserve the life of your filter.
How often do I need to substitute my air filter based on thickness?
The longevity of an air filter also relies on the thickness. A 1" filter will need to be changed out more often instead of a 4" filter.
- A 1" pleated air filter ought to be changed every 30-60 days.
- A 2" pleated air filter ought to be exchanged every 3 months.
- A 3” pleated air filter should be switched every 120 days.
- A 4" pleated air filter ought to be swapped out every 6 months.
- A 5” or 6" pleated air filter must be swapped every 9-12 months.
One of the perks of denser filters is not only do they last longer, but they also boast a higher MERV Rating. This means they can do a superior job of eliminating the particles within your home. They also produce less air resistance, which can help your HVAC system function more proficiently and reduce strain on components including the blower motor.
If you want a whole-home air purifier, you will also have to replace the filters more often.
How frequently should I exchange my air filter if I own a dog or cat?
If you own pets, you might need to replace your air filter more often. Pet hair and dander can rapidly clog an air filter and lower its effectiveness. For every shedding dog you want, expect to switch out the filter a month earlier than you would in a home with no pets. The same is true of cats, although they tend not to 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 often.
Even though it's a good rule of thumb, you will need to check your air filter more regularly to see if it has to be replaced. Dogs don't shed at the same rate all year. They shed more in the spring and fall when they are blowing their coat. Check the air filter every month and replace it when it seems clogged.
Here are averages that might help you recognize how often you should put in a new air filter at your residence:
- Vacation house or an individual occupant and no pets or allergies: every 6–12 months
- Standard suburban home without pets: every 3 months
- One dog or cat: every 2 months
- More than one pet or if someone has allergies: 20–45 days