How often you have to change your air filters could depend on the following:
- Air filter type
- Overall indoor air quality
- Number of pets
- Household size
- Air pollution levels and construction near the residence
- Your MERV Rating
For basic 1"–3" air filters, manufacturers usually instruct you to change them every 30–90 days. If you suffer from mild to moderate allergies, you can use a better air filter or change them even more often.
The quick answer to "how frequently should I swap my air filter?":
If there isn't a smoker or pets at 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 changing it.
What air filter models survive longer?
Many air filters are designed to last up to six months, while others should be replaced each month. The thicker the air filter, the longer it will last. Overall, you should examine the thickness of the filter as opposed to the brand. You also need to consider at the MERV Rating.
The MERV Rating is a scale that goes from 1-20 and calculates how effectively an air filter should pull particles out of the air. The bigger the MERV Rating, the smaller the particle that can be caught by your 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 have to replace the filter more frequently. And if you own an older system, plan to substitute the filter more frequently to preserve the life of your filter.
How often do I need to substitute my air filter based on thickness?
The lifespan of an air filter also relies on its thickness. A 1" filter will have to be exchanged more often than a 4" filter.
- A 1" pleated air filter ought to be changed every 30-60 days.
- A 2" pleated air filter must be exchanged every 90 days.
- A 3” pleated air filter must be switched every 4 months.
- A 4" pleated air filter ought to be replaced every 6 months.
- A 5” or 6" pleated air filter should be swapped every 9-12 months.
One of the benefits of denser filters is not only do they live longer, but they also provide a higher MERV Rating. This means they will do a better job of eliminating the particles in your home. They also produce less air resistance, which can help your HVAC system operate more efficiently and reduce strain on components like the blower motor.
If you have a whole-house air purifier, you will also need to switch out the filters more regularly.
How often should I change my air filter if I want a dog or cat?
If you own pets, you might have to switch out your air filter more often. Pet hair and dander can quickly clog an air filter and minimize its effectiveness. For every shedding dog you own, expect to exchange the filter a month earlier than you would with a home with no pets. The same is true of cats, although they usually do not 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.
Despite being a good rule of thumb, you might want to examine your air filter more frequently to determine if it needs to be replaced. Dogs tend not to shed the same amount year-round. They shed more in the spring and fall when they are blowing their coat. Take a look at the air filter each month and exchange it when it seems clogged.
Here are averages that might help you learn how regularly you should get a new air filter at your residence:
- Vacation house or one occupant and no pets or allergies: every 6–12 months
- Standard suburban home without pets: every 90 days
- A single dog or cat: every 60 days
- More than one pet or if anyone has allergies: 20–45 days