How often should I change my air filter at home?

change air filter

How frequently you have to replace the air filters can depend on the following:

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

For basic 1"–3" air filters, companies normally instruct you to exchange them every 30–90 days. If you suffer from mild to moderate allergies, you could put in a better air filter or replace them even more frequently.

The quick answer to "how often do I need to switch out my air filter?":

If you don't have a smoker or pets in your home, and the filter is the commonly sold 1" filter with a MERV rating of 4, you should be able to wait up to 90 days before switching it.

What air filter brands survive longer?

Many air filters are manufactured to survive up to six months, while others should be swapped month-to-month. The denser the air filter, the longer it will last. Overall, you need to examine the thickness of the filter versus the brand. You also need to check at the MERV Rating.

The MERV Rating is a scale that goes from 1-20 and calculates how efficiently an air filter can remove particles out of the air. The bigger the MERV Rating, the smaller the particle that can be captured by the air filter.

While a filter with a higher MERV Rating might last longer, it may also hamper the flow of air in your home. And you will have to replace the filter more frequently. And if you own an older system, plan to substitute the filter more frequently to conserve the quality of your filter.

How often do I need to substitute my air filter based on thickness?

The lifespan of an air filter also relies on its thickness. A 1" filter will have to be changed out more frequently compared to a 4" filter.

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

One of the benefits of thicker filters is not only do they survive longer, but they also posses a higher MERV Rating. This means they will do a superior job of getting rid of the particles in your home. They also produce less air resistance, which can help an HVAC system work more proficiently and limit strain on components including the blower motor.

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

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

If you want pets, you might have to change out your air filter more frequently. Pet hair and dander can quickly clog an air filter and minimize its effectiveness. For every shedding dog you want, expect to exchange the filter a month sooner than you would for a home lacking pets. The same applies to cats, although they don't shed as often as dogs. If you own a hypoallergenic or non-shedding dog or cat, you might not need to exchange your air filter as frequently.

Despite being a good rule of thumb, you might want to examine the air filter more often to decide if it has to 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. Inspect the air filter every month and exchange it when it seems clogged.

Here are averages that may help you learn how regularly 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
  • Common 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