How often should I change my air filter at home?

How regularly you have to replace the air filters could depend on the following:

Air filter style
Overall indoor air quality
Quantity of pets
Household size
Air pollution levels and construction around the residence
The MERV Rating

For common 1"–3" air filters, manufacturers normally ask you to swap them every 30–90 days. If someone in your family suffers from light to moderate allergies, you could use a better air filter or exchange them even more often.

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

If there isn't a smoker or pets in the home, and the filter is the often 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 models survive longer?

Many air filters are supposed to last up to six months, while others should be switched each month. The larger the air filter, the longer it can last. In general, you should look at the thickness of the filter as opposed to 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 well an air filter can remove particles from the air. The better the MERV Rating, the smaller the particle that will be captured by your air filter.

While a filter with a higher MERV Rating will last longer, it might also impede the airflow in your home. And you will have to switch out the filter more frequently. And if you have an older system, plan to change the filter more regularly to conserve the quality of your filter.

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

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

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

One of the benefits of thicker filters is not only do they last longer, but they also boast a better MERV Rating. This means they can do a superior job of filtering out the particles within your home. They also generate less air resistance, which can help an HVAC system work more effectively and cut down on strain on components like the blower motor.

If you have a whole-home air purifier, you will also have to switch out the filters more regularly.

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

If you have pets, you might have to exchange your air filter more often. Pet hair and dander can easily clog an air filter and lower its effectiveness. For every shedding dog you have, expect to exchange the filter a month sooner than you would in a home with no pets. The same goes for cats, although they tend not to shed as much as dogs. If you want a hypoallergenic or non-shedding dog or cat, you might not have to switch out your air filter as often.

Although a good rule of thumb, you might want to check the air filter more often to determine if it should be replaced. 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. Take a look at the air filter every month and change it when it seems clogged.

Here are averages that may help you recognize how often 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 3 months
One dog or cat: every 2 months
More than one pet or if a member of your family has allergies: 20–45 days