How often should I change my air filter at home?

change air filter

How frequently you have to change the air filters might be on the following:

  • Air filter type
  • Overall indoor air quality
  • Number of pets
  • Household size
  • Air pollution levels and construction nearby the residence
  • Your MERV Rating

For standard 1"–3" air filters, companies usually tell you to replace them every 30–90 days. If you suffer from mild to moderate allergies, you can use a better air filter or replace them even more frequently.

The quick answer to "how frequently do I have to switch out the air filter?":

If there isn't a smoker or pets in the home, and your filter is the commonly 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 designed to last up to six months, while others should be changed monthly. The larger the air filter, the longer it should last. Generally, you need to look at the thickness of the filter versus the brand. You also need to take a look at the MERV Rating.

The MERV Rating is a scale that goes from 1-20 and measures how well an air filter should eliminate particles from the air. The higher the MERV Rating, the smaller the particle that will be caught by your air filter.

While a filter with a higher MERV Rating can last longer, it might also impede the airflow in your home. And you will have to exchange the filter more regularly. And if you own an older piece of equipment, plan to switch out the filter more frequently to maintain the life of your filter.

How often do I have to replace my air filter based on thickness?

The lifespan of an air filter also depends on its thickness. A 1" filter will have to be exchanged more often than a 4" filter.

  • A 1" pleated air filter should be exchanged every 30-60 days.
  • A 2" pleated air filter must be replaced every 3 months.
  • A 3” pleated air filter must be switched every 120 days.
  • A 4" pleated air filter must be replaced every 6 months.
  • A 5” or 6" pleated air filter must be changed out every 9-12 months.

One of the perks of denser filters is not only do they survive longer, but they also boast a higher MERV Rating. This means they can do a better job of eliminating the particles inside your home. They also produce less air resistance, which can help your HVAC system work more proficiently and cut down on strain on components like the blower motor.

If you want a whole-house air purifier, you will also have to switch out the filters more often.

How frequently should I change my air filter if I have a dog or cat?

If you own pets, you might need to exchange your air filter more regularly. Pet hair and dander can quickly clog an air filter and reduce its effectiveness. For each shedding dog you want, expect to exchange the filter a month earlier than you would in a home with no pets. The same applies to cats, although they usually do not shed as heavily as dogs. If you own a hypoallergenic or non-shedding dog or cat, you might not have to replace your air filter as frequently.

Even though it's a good rule of thumb, you might want to check the air filter more frequently to decide if it has to be exchanged. Dogs usually do not shed at the same rate year-round. 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
  • Average suburban home without pets: every 90 days
  • One dog or cat: every 60 days
  • More than one pet or if someone has allergies: 20–45 days
chat now widget box