How regularly you have to change your air filters could rely on the following:
- Air filter style
- Total indoor air quality
- Quantity of pets
- Household size
- Air pollution levels and construction around the residence
- Your MERV Rating
For basic 1"–3" air filters, manufacturers generally instruct 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 often.
The quick answer to "how frequently do I have to exchange my air filter?":
If you don't have a smoker or pets at home, and the filter is the widely 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 brands survive longer?
Some air filters are supposed to last up to six months, while others should be changed monthly. The thicker the air filter, the longer it can last. Overall, you need to examine the thickness of the filter instead of the brand. You also need to consider at the MERV Rating.
The MERV Rating is a scale that stretches from 1-20 and assesses how well an air filter should eliminate particles out of the air. The higher the MERV Rating, the smaller the particle that can be captured by your air filter.
While a filter with a higher MERV Rating will last longer, it may also restrict the ventilation in your home. And you will need to switch out the filter more often. And if you acquire an older piece of equipment, plan to change the filter more frequently to maintain the life of your filter.
How often do I have to replace my air filter based on thickness?
The lifespan of an air filter also relies on the thickness. A 1" filter will have to be exchanged more often than a 4" filter.
- A 1" pleated air filter must be changed every 30-60 days.
- A 2" pleated air filter must be replaced every 3 months.
- A 3” pleated air filter must be switched every 4 months.
- A 4" pleated air filter should be swapped out every 6 months.
- A 5” or 6" pleated air filter must be swapped every 9-12 months.
One of the advantages of thicker filters is not only do they live longer, but they also provide a better MERV Rating. This means they should do a better job of eliminating the particles in your home. They also generate less air resistance, which can help your HVAC system operate more proficiently and reduce wear and tear on components like the blower motor.
If you want a whole-home air purifier, you will also need to replace the filters more regularly.
How often should I exchange my air filter if I own a dog or cat?
If you want pets, you might have to exchange your air filter more frequently. Pet hair and dander can quickly clog an air filter and minimize its effectiveness. For each shedding dog you want, expect to exchange the filter a month earlier than you would in a home without pets. The same is true of cats, although they don't shed as often as dogs. If you want a hypoallergenic or non-shedding dog or cat, you might not have to replace your air filter as frequently.
Although a good rule of thumb, you will need to examine your air filter more frequently to decide if it has to be exchanged. Dogs don't shed the same amount all year. 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 can help you learn how frequently you should get a new air filter at your residence:
- Vacation house or a single occupant and no pets or allergies: every 6–12 months
- Ordinary suburban home without pets: every 3 months
- One dog or cat: every 60 days
- More than one pet or if a member of your family has allergies: 20–45 days