How often you need to change the air filters can depend on the following:
- Air filter model
- Total indoor air quality
- Quantity of pets
- Household size
- Air pollution levels and construction around the residence
- The MERV Rating
For basic 1"–3" air filters, brands normally ask you to change them every 30–90 days. If you suffer from light to moderate allergies, you can put in a better air filter or replace them even more regularly.
The short answer to "how often do I need to swap the air filter?":
If you don't have a smoker or pets in your home, and the filter is the widely 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 brands last longer?
Many air filters are manufactured to last up to six months, while others need to be replaced each month. The larger the air filter, the longer it should last. In general, you should examine 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 measures how efficiently an air filter can remove particles from the air. The better the MERV Rating, the smaller the particle that can be captured by the air filter.
While a filter with a higher MERV Rating can last longer, it may also impede the circulation in your home. And you will have to replace the filter more often. And if you acquire an older piece of equipment, plan to substitute the filter more often to conserve the life of your filter.
How frequently should I replace my air filter based on thickness?
The longevity of an air filter also counts on its thickness. A 1" filter will have to be exchanged more frequently instead of a 4" filter.
- A 1" pleated air filter must be exchanged every 30-60 days.
- A 2" pleated air filter must be switched every 3 months.
- A 3” pleated air filter ought to be switched every 4 months.
- A 4" pleated air filter ought to be swapped out every 6 months.
- A 5” or 6" pleated air filter ought to be swapped every 9-12 months.
One of the perks of thicker filters is not only do they survive longer, but they also have a higher MERV Rating. This means they will do a more effective job of eliminating the particles in your home. They also create less air resistance, which can help an HVAC system work more effectively and limit 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 often.
How regularly should I replace my air filter if I have a dog or cat?
If you have pets, you might have to replace your air filter more often. Pet hair and dander can quickly clog an air filter and minimize its effectiveness. For every shedding dog you have, expect to replace 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 heavily as dogs. If you have a hypoallergenic or non-shedding dog or cat, you might not need to switch out your air filter as often.
Despite being a good rule of thumb, you will need to check the air filter more often to determine if it has to be swapped out. Dogs don't shed at the same rate all year. They shed more in the spring and fall when they are blowing their coat. Take a look at the air filter each month and change it when it seems clogged.
Here are averages that may help you understand how regularly you should install a new air filter at your residence:
- Vacation house or an individual occupant and no pets or allergies: every 6–12 months
- Ordinary suburban home without pets: every 3 months
- One dog or cat: every 60 days
- More than one pet or if a member of your family has allergies: 20–45 days