How frequently you should exchange the air filters can be on the following:
- Air filter model
- Overall indoor air quality
- Quantity of pets
- Household size
- Air pollution levels and construction near the residence
- The MERV Rating
For common 1"–3" air filters, companies generally ask you to change them every 30–90 days. If someone in your family suffers from mild to moderate allergies, you could use a better air filter or change them even more frequently.
The short answer to "how often do I need to replace the air filter?":
If there isn't a smoker or pets in the 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 prior to replacing it.
What air filter types survive longer?
Many air filters are manufactured to survive up to six months, while others should be swapped month-to-month. The larger the air filter, the longer it should last. Overall, you need to examine the thickness of the filter as opposed to the brand. You also need to look at the MERV Rating.
The MERV Rating is a scale that stretches from 1-20 and measures how well an air filter should remove particles from the air. The bigger the MERV Rating, the smaller the particle that could be captured by the air filter.
While a filter with a higher MERV Rating can last longer, it can also restrict the flow of air in your home. And you will have to switch out the filter more frequently. And if you own an older piece of equipment, plan to change the filter more frequently to maintain the life of your filter.
How frequently do I have to switch out my air filter based on thickness?
The lifespan of an air filter also relies on the thickness. A 1" filter will need to be replaced 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 replaced every 90 days.
- A 3” pleated air filter should be exchanged every 120 days.
- A 4" pleated air filter ought to be changed out every 6 months.
- A 5” or 6" pleated air filter should be changed out every 9-12 months.
One of the advantages of denser filters is not only do they last longer, but they also boast a higher MERV Rating. This means they can do a superior job of getting rid of the particles within your home. They also create less air resistance, which can help ones HVAC system run more proficiently and decrease strain on components such as the blower motor.
If you have a whole-home air purifier, you will also need to replace the filters more frequently.
How frequently should I replace my air filter if I own a dog or cat?
If you have pets, you might need to change out your air filter more frequently. Pet hair and dander can quickly clog an air filter and lower its effectiveness. For each shedding dog you want, expect to change out the filter a month earlier than you would in a home with no pets. The same goes for cats, although they don't shed as heavily as dogs. If you want a hypoallergenic or non-shedding dog or cat, you might not have to replace your air filter as much.
Even though it's a good rule of thumb, you will need to check your air filter more often to figure out if it has to 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 monthly and exchange it when it appears clogged.
Here are averages that can help you know how often 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 90 days
- One dog or cat: every 60 days
- More than one pet or if somebody has allergies: 20–45 days