How frequently you need to change your air filters could depend on the following:
- Air filter design
- Overall indoor air quality
- Number of pets
- Household size
- Air pollution levels and construction nearby the residence
- Your MERV Rating
For basic 1"–3" air filters, manufacturers normally instruct you to exchange them every 30–90 days. If someone in your family suffers from mild to moderate allergies, you could put in a better air filter or replace them even more frequently.
The shortest answer to "how frequently do I need to change the air filter?":
If there isn't a smoker or pets in your 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 changing it.
What air filter brands survive longer?
Many air filters are designed to last up to six months, while others need to be changed month-to-month. The larger the air filter, the longer it can last. In general, you should check 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 goes from 1-20 and measures how efficiently an air filter can eliminate particles from the air. The higher the MERV Rating, the smaller the particle that can be captured by the air filter.
While a filter with a higher MERV Rating will last longer, it could also interfere with the ventilation in your home. And you will have to replace the filter more often. And if you have an older piece of equipment, plan to substitute the filter more regularly to preserve the quality of your filter.
How frequently should I exchange my air filter based on thickness?
The longevity of an air filter also counts on its thickness. A 1" filter will need to be exchanged more frequently instead of a 4" filter.
- A 1" pleated air filter should be exchanged every 30-60 days.
- A 2" pleated air filter ought to be switched every 3 months.
- A 3” pleated air filter ought to be replaced every 120 days.
- A 4" pleated air filter must be exchanged every 6 months.
- A 5” or 6" pleated air filter must be changed out every 9-12 months.
One of the benefits of thicker filters is not only do they live longer, but they also posses a higher MERV Rating. This means they will do a superior job of getting rid of the particles within your home. They also create less air resistance, which can help your HVAC system operate more effectively and limit wear and tear on components like the blower motor.
If you own a whole-home air purifier, you will also have to switch out the filters more frequently.
How often should I exchange my air filter if I own a dog or cat?
If you want pets, you might need to switch out your air filter more often. Pet hair and dander can quickly clog an air filter and minimize its effectiveness. For each shedding dog you have, expect to change out the filter a month earlier than you would with a home lacking pets. The same goes for 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 change out your air filter as often.
Even though it's a good rule of thumb, you will need to check your air filter more often to decide if it needs to be replaced. Dogs usually do not shed the same amount 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 appears clogged.
Here are averages that might help you learn how often you should get a new air filter at your residence:
- Vacation house or one occupant and no pets or allergies: every 6–12 months
- Ordinary suburban home without pets: every 3 months
- A single dog or cat: every 2 months
- More than one pet or if someone has allergies: 20–45 days