How regularly you need to replace your air filters could be on the following:
- Air filter type
- Total indoor air quality
- Number of pets
- Household size
- Air pollution levels and construction nearby the residence
- The MERV Rating
For common 1"–3" air filters, companies generally ask you to change them every 30–90 days. If you suffer from mild to moderate allergies, you could install a better air filter or replace them even more often.
The quick answer to "how often do I have to switch out the air filter?":
If there isn't 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 before switching it.
What air filter brands last longer?
Some air filters are manufactured to last up to six months, while others have to be swapped each month. The larger the air filter, the longer it can last. Overall, you can examine the thickness of the filter rather than the brand. You also need to check 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 will be captured by the air filter.
While a filter with a higher MERV Rating should last longer, it may also hamper the ventilation in your home. And you will have to exchange the filter more regularly. And if you own an older system, plan to exchange the filter more frequently to preserve 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 its thickness. A 1" filter will have to be exchanged more often versus a 4" filter.
- A 1" pleated air filter ought to be exchanged every 30-60 days.
- A 2" pleated air filter must be replaced every 3 months.
- A 3” pleated air filter ought to be changed out every 120 days.
- A 4" pleated air filter must be exchanged every 6 months.
- A 5” or 6" pleated air filter should be swapped every 9-12 months.
One of the benefits of thicker filters is not only do they survive longer, but they also have a better MERV Rating. This means they can do a superior job of filtering out the particles in your home. They also create less air resistance, which can help your HVAC system function more proficiently and cut down on strain on components like the blower motor.
If you own a whole-house air purifier, you will also have to replace the filters more regularly.
How regularly should I replace my air filter if I have a dog or cat?
If you have pets, you might have to switch out your air filter more frequently. Pet hair and dander can rapidly clog an air filter and minimize its effectiveness. For each shedding dog you own, expect to switch out the filter a month sooner than you would in a home lacking pets. The same is true of cats, although they usually do not shed as much as dogs. If you have a hypoallergenic or non-shedding dog or cat, you might not have to replace your air filter as frequently.
Despite being a good rule of thumb, you might want to examine the air filter more regularly to decide if it should be replaced. Dogs tend not to shed the same amount all year. They shed more in the spring and fall when they are blowing their coat. Inspect the air filter every month and change it when it appears clogged.
Here are averages that can help you understand how regularly you should put in a new air filter at your residence:
- Vacation house or a single occupant and no pets or allergies: every 6–12 months
- Standard suburban home without pets: every 90 days
- One dog or cat: every 60 days
- More than one pet or if a member of your family has allergies: 20–45 days