How frequently you have to replace the air filters might depend on the following:
- Air filter type
- Total indoor air quality
- Quantity of pets
- Household size
- Air pollution levels and construction near the residence
- Your MERV Rating
For basic 1"–3" air filters, brands typically ask you to swap them every 30–90 days. If you suffer from light to moderate allergies, you could put in a better air filter or exchange them even more frequently.
The short answer to "how frequently do I need to swap my air filter?":
If you don't have a smoker or pets in the home, and your filter is the often sold 1" filter with a MERV rating of 4, you should be able to wait up to 90 days before changing it.
What air filter models last longer?
Some air filters are designed to last up to six months, while others need to be exchanged each month. The thicker the air filter, the longer it will last. In most cases, you need to check the thickness of the filter instead of 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 should 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 should last longer, it can also interfere with the ventilation in your home. And you will need to replace the filter more regularly. And if you have an older system, plan to switch out the filter more often to conserve the quality of your filter.
How regularly do I need to replace my air filter based on thickness?
The lifespan of an air filter also counts on the thickness. A 1" filter will have to be exchanged more frequently versus a 4" filter.
- A 1" pleated air filter must be replaced every 30-60 days.
- A 2" pleated air filter must be replaced every 3 months.
- A 3” pleated air filter should be replaced every 120 days.
- A 4" pleated air filter ought to be changed out every 6 months.
- A 5” or 6" pleated air filter must be replaced every 9-12 months.
One of the benefits of thicker filters is not only do they survive longer, but they also boast a better MERV Rating. This means they should do a more effective job of filtering out the particles inside your home. They also create less air resistance, which can help ones HVAC system run more proficiently and reduce strain on components like the blower motor.
If you own a whole-house air purifier, you will also need to replace the filters more frequently.
How often should I exchange my air filter if I own a dog or cat?
If you have pets, you might need to exchange your air filter more frequently. Pet hair and dander can rapidly clog an air filter and lower its effectiveness. For each shedding dog you have, expect to change out the filter a month sooner than you would in a home lacking pets. The same is true of cats, although they tend not to shed as heavily as dogs. If you own 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 your air filter more regularly to figure out if it has 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. Check the air filter each month and exchange it when it seems clogged.
Here are averages that may help you learn how often you should put in a new air filter at your residence:
- Vacation house or one occupant and no pets or allergies: every 6–12 months
- Average suburban home without pets: every 90 days
- A single dog or cat: every 60 days
- More than one pet or if anyone has allergies: 20–45 days