How often should I change my air filter at home?

change air filter

How regularly you should replace the air filters might be on the following:

  • Air filter style
  • Total indoor air quality
  • Quantity of pets
  • Household size
  • Air pollution levels and construction surrounding the residence
  • Your MERV Rating

For basic 1"–3" air filters, manufacturers generally tell you to replace 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 quick answer to "how often should I change my air filter?":

If there isn't a smoker or pets in your home, and your filter is the widely 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?

Many air filters are manufactured to survive up to six months, while others should be changed monthly. The larger the air filter, the longer it will last. Overall, you should examine the thickness of the filter instead of 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 calculates how well an air filter will eliminate 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 may also impede the circulation in your home. And you will have to exchange the filter more frequently. And if you have an older piece of equipment, plan to change the filter more often to conserve the life of your filter.

How often should I substitute my air filter based on thickness?

The longevity of an air filter also depends on the thickness. A 1" filter will have to be exchanged more frequently than a 4" filter.

  • A 1" pleated air filter must be changed out every 30-60 days.
  • A 2" pleated air filter ought to be swapped out every 90 days.
  • A 3” pleated air filter should be switched every 120 days.
  • A 4" pleated air filter must be exchanged every 6 months.
  • A 5” or 6" pleated air filter should be changed out every 9-12 months.

One of the advantages of thicker filters is not only do they live longer, but they also boast a higher MERV Rating. This means they can do a more effective job of eliminating the particles in your home. They also generate less air resistance, which can help an HVAC system operate more effectively and reduce strain on components such as the blower motor.

If you want a whole-house air purifier, you will also have to exchange the filters more frequently.

How often should I replace my air filter if I have a dog or cat?

If you own pets, you might have to exchange your air filter more frequently. Pet hair and dander can rapidly clog an air filter and minimize its effectiveness. For each shedding dog you own, expect to replace the filter a month earlier than you would in a home lacking pets. The same applies to cats, although they usually do not shed as heavily as dogs. If you have a hypoallergenic or non-shedding dog or cat, you might not have to change out your air filter as frequently.

Even though it's a good rule of thumb, you will need to check your air filter more frequently to see if it needs to be exchanged. Dogs usually do not shed the same amount year-round. 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 looks clogged.

Here are averages that can help you understand how often you should get a new air filter at your residence:

  • Vacation house or an individual occupant and no pets or allergies: every 6–12 months
  • Average suburban home without pets: every 90 days
  • A single dog or cat: every 2 months
  • More than one pet or if a member of your family has allergies: 20–45 days