How regularly you need to change the air filters might rely on the following:
- Air filter style
- Total indoor air quality
- Number of pets
- Household size
- Air pollution levels and construction surrounding the residence
- Your MERV Rating
For standard 1"–3" air filters, companies typically ask you to replace them every 30–90 days. If you suffer from light to moderate allergies, you could use a better air filter or change them even more frequently.
The shortest answer to "how often do I need to exchange my air filter?":
If you don't have a smoker or pets in your home, and your filter is the widely 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 styles survive longer?
Some air filters are designed to last up to six months, while others have to be exchanged monthly. The denser the air filter, the longer it can last. Overall, you need to check 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 stretches from 1-20 and measures how efficiently an air filter can pull particles out of the air. The higher the MERV Rating, the smaller the particle that could be caught by your air filter.
While a filter with a higher MERV Rating might last longer, it can also interfere with the circulation in your home. And you will have to replace the filter more often. And if you own an older system, plan to switch out the filter more frequently to maintain the quality of your filter.
How frequently do I need to substitute my air filter based on thickness?
The longevity of an air filter also hinges on the thickness. A 1" filter will need to be changed out more frequently compared to a 4" filter.
- A 1" pleated air filter should be exchanged every 30-60 days.
- A 2" pleated air filter should be exchanged every 3 months.
- A 3” pleated air filter must be exchanged every 4 months.
- A 4" pleated air filter ought to be swapped out every 6 months.
- A 5” or 6" pleated air filter should be swapped every 9-12 months.
One of the perks of denser filters is not only do they survive longer, but they also posses a better MERV Rating. This means they should do a superior job of eliminating the particles within your home. They also generate less air resistance, which can help ones HVAC system work more efficiently and decrease strain on components like the blower motor.
If you want a whole-house air purifier, you will also need to switch out the filters more often.
How regularly should I change my air filter if I have a dog or cat?
If you want pets, you might have to replace your air filter more frequently. Pet hair and dander can easily clog an air filter and reduce its effectiveness. For every shedding dog you have, expect to switch out the filter a month sooner than you would with a home lacking pets. The same is true of cats, although they don't shed as often as dogs. If you own a hypoallergenic or non-shedding dog or cat, you might not have to change out your air filter as frequently.
Although a good rule of thumb, you might want to check your air filter more frequently to determine if it should be swapped out. Dogs tend not to shed the same amount year-round. They shed more in the spring and fall when they are blowing their coat. Inspect the air filter each month and exchange it when it looks clogged.
Here are averages that can help you know 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
- Common suburban home without pets: every 3 months
- One dog or cat: every 2 months
- More than one pet or if a member of your family has allergies: 20–45 days