How often should I change my air filter at home?

How regularly you need to change the air filters may be on the following:

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

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

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 your 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 changing it.

What air filter styles last longer?

Many air filters are designed to survive up to six months, while others need to be exchanged each month. The thicker the air filter, the longer it should last. Generally, you need to check the thickness of the filter rather than the brand. You also need to take a look at the MERV Rating.

The MERV Rating is a scale that stretches from 1-20 and calculates how efficiently an air filter can remove particles from the air. The better the MERV Rating, the smaller the particle that could be captured by your air filter.

While a filter with a higher MERV Rating will last longer, it may also restrict the circulation in your home. And you will need to change the filter more frequently. And if you have an older piece of equipment, plan to switch out the filter more often to maintain the life of your filter.

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

The lifespan of an air filter also counts on the thickness. A 1" filter will need to be replaced more frequently than a 4" filter.

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

One of the advantages of thicker filters is not only do they live longer, but they also posses a better MERV Rating. This means they should do a superior job of filtering out the particles inside your home. They also create less air resistance, which can help ones HVAC system work more proficiently and reduce strain on components like the blower motor.

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

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

If you own pets, you might have to replace your air filter more frequently. Pet hair and dander can quickly clog an air filter and limit its effectiveness. For each shedding dog you have, expect to replace the filter a month sooner than you would with a home lacking pets. The same is true of cats, although they usually do not shed as heavily as dogs. If you want a hypoallergenic or non-shedding dog or cat, you might not need to exchange your air filter as much.

Although a good rule of thumb, you will need to examine the air filter more often to see if it should be replaced. Dogs don't 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 can help you know how regularly you should put in a new air filter at your residence:

Vacation house or a single occupant and no pets or allergies: every 6–12 months
Standard suburban home without pets: every 90 days
One dog or cat: every 60 days
More than one pet or if a member of your family has allergies: 20–45 days