How regularly you have to change the air filters may depend on the following:
- Air filter design
- Total indoor air quality
- Quantity of pets
- Household size
- Air pollution levels and construction nearby the residence
- The MERV Rating
For basic 1"–3" air filters, manufacturers normally tell you to change them every 30–90 days. If you suffer from light to moderate allergies, you can use a better air filter or replace them even more regularly.
The quick answer to "how frequently do I have to exchange the air filter?":
If you don't have a smoker or pets in the 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 prior to switching it.
What air filter brands survive longer?
Many air filters are supposed to last up to six months, while others have to be changed each month. The larger the air filter, the longer it will last. In general, you can examine the thickness of the filter rather than the brand. You also need to consider at the MERV Rating.
The MERV Rating is a scale that stretches from 1-20 and calculates how well an air filter should pull particles from the air. The better the MERV Rating, the smaller the particle that could be captured by the air filter.
While a filter with a higher MERV Rating might last longer, it could also hamper the ventilation in your home. And you will have to switch out the filter more frequently. And if you acquire an older piece of equipment, plan to change the filter more frequently to maintain the quality of your filter.
How regularly do I have to exchange my air filter based on thickness?
The lifespan of an air filter also depends on its thickness. A 1" filter will have to be changed out more frequently compared to a 4" filter.
- A 1" pleated air filter should be changed every 30-60 days.
- A 2" pleated air filter must be exchanged every 90 days.
- A 3” pleated air filter must be exchanged every 120 days.
- A 4" pleated air filter should 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 denser filters is not only do they last longer, but they also boast a better MERV Rating. This means they will do a better job of getting rid of the particles within your home. They also generate less air resistance, which can help ones HVAC system work more effectively and cut down on strain on components including the blower motor.
If you want a whole-house air purifier, you will also need to exchange the filters more often.
How often should I change my air filter if I want a dog or cat?
If you own pets, you might have to replace your air filter more regularly. Pet hair and dander can rapidly clog an air filter and minimize its effectiveness. For every shedding dog you have, expect to exchange the filter a month sooner than you would for a home with no pets. The same is true of cats, although they usually do not shed as often as dogs. If you own a hypoallergenic or non-shedding dog or cat, you might not need to change out your air filter as frequently.
Despite being a good rule of thumb, you will need to examine the air filter more regularly to figure out if it needs to be exchanged. Dogs usually do not shed the same amount all year. They shed more in the spring and fall when they are blowing their coat. Inspect the air filter every month and change it when it seems clogged.
Here are averages that can help you learn how frequently you should put in a new air filter at your residence:
- Vacation house or one occupant and no pets or allergies: every 6–12 months
- Common suburban home without pets: every 90 days
- One dog or cat: every 60 days
- More than one pet or if someone has allergies: 20–45 days