How frequently you need to replace your air filters can rely on the following:
- Air filter model
- Overall indoor air quality
- Quantity of pets
- Household size
- Air pollution levels and construction nearby the residence
- The MERV Rating
For common 1"–3" air filters, manufacturers usually instruct you to change them every 30–90 days. If someone in your family suffers from light to moderate allergies, you can use a better air filter or replace them even more frequently.
The quick answer to "how often do I need to swap my air filter?":
If you don't have a smoker or pets at 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 prior to switching it.
What air filter models last longer?
A few air filters are supposed to last up to six months, while others should be changed month-to-month. The larger the air filter, the longer it can last. In general, you should examine the thickness of the filter versus 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 efficiently an air filter will remove particles from the air. The bigger the MERV Rating, the smaller the particle that can be caught by your air filter.
While a filter with a higher MERV Rating can last longer, it may also hamper the circulation in your home. And you will have to replace the filter more frequently. And if you have an older piece of equipment, plan to switch out the filter more frequently to conserve the quality of your filter.
How frequently should I substitute my air filter based on thickness?
The longevity of an air filter also hinges on its thickness. A 1" filter will need to be replaced more frequently versus a 4" filter.
- A 1" pleated air filter must be changed out every 30-60 days.
- A 2" pleated air filter must be switched every 90 days.
- A 3” pleated air filter ought to be changed out every 4 months.
- A 4" pleated air filter should be exchanged every 6 months.
- A 5” or 6" pleated air filter ought to be replaced every 9-12 months.
One of the benefits of denser filters is not only do they live longer, but they also boast a better 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 function more efficiently and limit strain on components such as the blower motor.
If you want a whole-house air purifier, you will also have to switch out the filters more often.
How often should I exchange my air filter if I own a dog or cat?
If you have pets, you might need to exchange your air filter more frequently. Pet hair and dander can rapidly clog an air filter and lower its effectiveness. For each shedding dog you own, expect to replace the filter a month earlier than you would in a home lacking pets. The same goes for cats, although they don't 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 will need to examine your air filter more often to determine if it has to be swapped out. Dogs usually do not shed at the same rate all year. They shed more in the spring and fall when they are blowing their coat. Inspect the air filter each month and replace it when it looks clogged.
Here are averages that may help you understand how often 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
- Common suburban home without pets: every 3 months
- A single dog or cat: every 60 days
- More than one pet or if somebody has allergies: 20–45 days