How often should I change my air filter at home?

How regularly you should exchange your air filters could depend on the following:

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

For standard 1"–3" air filters, companies normally ask you to change them every 30–90 days. If you suffer from light to moderate allergies, you can use a better air filter or change them even more often.

The quick answer to "how often do I have to swap the air filter?":

If you don't have a smoker or pets in the 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 replacing it.

What air filter models last longer?

A few air filters are supposed to survive up to six months, while others have to be switched month-to-month. The thicker the air filter, the longer it should last. Generally, you need to examine the thickness of the filter rather than the brand. You also need to look at the MERV Rating.

The MERV Rating is a scale that stretches from 1-20 and measures how well an air filter will pull particles out of the air. The bigger the MERV Rating, the smaller the particle that could be captured by your air filter.

While a filter with a higher MERV Rating might last longer, it might also hamper the airflow in your home. And you will need to switch out the filter more frequently. And if you own an older system, plan to substitute the filter more often to maintain the quality of your filter.

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

The lifespan of an air filter also counts on its thickness. A 1" filter will have to be replaced more often instead of a 4" filter.

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

One of the advantages of thicker filters is not only do they live longer, but they also have a better MERV Rating. This means they should do a superior job of getting rid of the particles within your home. They also generate less air resistance, which can help your HVAC system run more efficiently and limit wear and tear on components like the blower motor.

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

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

If you want pets, you might have to switch out your air filter more regularly. Pet hair and dander can easily clog an air filter and minimize its effectiveness. For every shedding dog you own, expect to switch out the filter a month earlier than you would for a home lacking pets. The same goes for 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 need to replace your air filter as much.

Although a good rule of thumb, you might want to examine the air filter more frequently to determine if it should be exchanged. Dogs usually do not 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 appears clogged.

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

Vacation house or an individual occupant and no pets or allergies: every 6–12 months
Standard suburban home without pets: every 3 months
A single dog or cat: every 60 days
More than one pet or if anyone has allergies: 20–45 days