How often you should exchange your air filters might be on the following:
- Air filter design
- Overall indoor air quality
- Quantity of pets
- Household size
- Air pollution levels and construction around the residence
- Your MERV Rating
For common 1"–3" air filters, manufacturers typically ask you to replace them every 30–90 days. If you suffer from light to moderate allergies, you can install a better air filter or change them even more often.
The short answer to "how often should I exchange the air filter?":
If you don't have a smoker or pets in the 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 switching it.
What air filter brands last longer?
Some air filters are supposed to survive up to six months, while others need to be exchanged monthly. The denser the air filter, the longer it will last. Overall, you need to examine the thickness of the filter versus the brand. You also need to consider at the MERV Rating.
The MERV Rating is a scale that records from 1-20 and calculates how well an air filter can remove particles from the air. The higher the MERV Rating, the smaller the particle that will be caught by the air filter.
While a filter with a higher MERV Rating will last longer, it might also impede the airflow in your home. And you will need to exchange the filter more regularly. And if you acquire an older system, plan to change the filter more often to extend the life of your filter.
How frequently should I switch out my air filter based on thickness?
The longevity of an air filter also counts on the thickness. A 1" filter will need to be changed out more often than a 4" filter.
- A 1" pleated air filter should be replaced every 30-60 days.
- A 2" pleated air filter ought to be switched 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 ought to be changed out every 9-12 months.
One of the benefits of denser filters is not only do they live longer, but they also boast a better MERV Rating. This means they should do a more effective job of filtering out the particles within your home. They also create less air resistance, which can help ones HVAC system run more effectively and reduce wear and tear on components like the blower motor.
If you own a whole-house air purifier, you will also need to replace the filters more often.
How often should I exchange my air filter if I own a dog or cat?
If you own pets, you might have to switch out your air filter more regularly. Pet hair and dander can quickly clog an air filter and limit its effectiveness. For every shedding dog you have, expect to replace the filter a month earlier than you would with a home lacking pets. The same goes for cats, although they don't shed as often as dogs. If you have a hypoallergenic or non-shedding dog or cat, you might not have to switch out your air filter as frequently.
Even though it's a good rule of thumb, you will need to check the air filter more often to see if it needs to be swapped out. Dogs tend not to 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 every month and change it when it seems clogged.
Here are averages that can help you learn how frequently you should install a new air filter at your residence:
- Vacation house or a single occupant and no pets or allergies: every 6–12 months
- Average suburban home without pets: every 3 months
- A single dog or cat: every 2 months
- More than one pet or if anyone has allergies: 20–45 days