How frequently you have to change your air filters can be on the following:
- Air filter model
- Overall indoor air quality
- Quantity of pets
- Household size
- Air pollution levels and construction surrounding the residence
- Your MERV Rating
For common 1"–3" air filters, brands normally ask you to change them every 30–90 days. If you suffer from mild to moderate allergies, you could use a better air filter or exchange them even more frequently.
The short answer to "how often should I switch out my air filter?":
If there isn't 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 types last longer?
Many air filters are supposed to last up to six months, while others have to be exchanged each month. The larger the air filter, the longer it can last. In general, you should 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 remove particles from the air. The higher the MERV Rating, the smaller the particle that could be captured by your air filter.
While a filter with a higher MERV Rating can last longer, it can also restrict the ventilation in your home. And you will need to replace the filter more often. And if you have an older piece of equipment, plan to change the filter more often to preserve the quality of your filter.
How frequently should I replace my air filter based on thickness?
The longevity of an air filter also depends on its thickness. A 1" filter will need to be swapped out more often than a 4" filter.
- A 1" pleated air filter ought to be replaced every 30-60 days.
- A 2" pleated air filter must be exchanged every 3 months.
- A 3” pleated air filter ought to be exchanged every 120 days.
- A 4" pleated air filter must be exchanged every 6 months.
- A 5” or 6" pleated air filter must be changed out every 9-12 months.
One of the benefits of thicker filters is not only do they survive longer, but they also have a higher MERV Rating. This means they will do a better job of getting rid of the particles in your home. They also produce less air resistance, which can help your HVAC system run more effectively and decrease strain on components such as the blower motor.
If you want a whole-house air purifier, you will also need to switch out the filters more frequently.
How often should I replace my air filter if I want a dog or cat?
If you own pets, you might need to switch out your air filter more frequently. Pet hair and dander can easily clog an air filter and lower its effectiveness. For each shedding dog you own, expect to replace the filter a month sooner than you would with a home with no pets. The same is true of cats, although they tend not to shed as much as dogs. If you have a hypoallergenic or non-shedding dog or cat, you might not have to exchange 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 should be replaced. Dogs don't shed at the same rate all year. They shed more in the spring and fall when they are blowing their coat. Check the air filter monthly and change it when it appears clogged.
Here are averages that might help you recognize 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
- 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