How often you need to replace the air filters can be on the following:
- Air filter design
- Overall indoor air quality
- Number of pets
- Household size
- Air pollution levels and construction near the residence
- The MERV Rating
For standard 1"–3" air filters, companies normally instruct you to change them every 30–90 days. If you suffer from mild to moderate allergies, you could use a better air filter or exchange them even more regularly.
The quick answer to "how frequently should I replace my air filter?":
If you don't have a smoker or pets in your 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 models survive longer?
Many air filters are supposed to survive up to six months, while others have to be switched each month. The denser the air filter, the longer it should last. In most cases, you need to examine 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 measures how efficiently an air filter can eliminate particles out of the air. The bigger the MERV Rating, the smaller the particle that could be caught by your air filter.
While a filter with a higher MERV Rating might last longer, it might also impede the airflow in your home. And you will have to replace the filter more often. And if you acquire an older system, plan to switch out the filter more often to maintain the quality of your filter.
How regularly do I need to exchange my air filter based on thickness?
The lifespan of an air filter also hinges on the thickness. A 1" filter will need to be swapped out more often versus a 4" filter.
- A 1" pleated air filter ought to be replaced every 30-60 days.
- A 2" pleated air filter must be replaced every 90 days.
- A 3” pleated air filter should be switched every 4 months.
- A 4" pleated air filter should be replaced every 6 months.
- A 5” or 6" pleated air filter should 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 more effective job of getting rid of the particles within your home. They also create less air resistance, which can help your HVAC system operate more proficiently and decrease strain on components such as the blower motor.
If you want a whole-house air purifier, you will also need to replace the filters more frequently.
How often should I exchange my air filter if I have a dog or cat?
If you want pets, you might have to change out your air filter more often. Pet hair and dander can quickly clog an air filter and limit its effectiveness. For each shedding dog you own, expect to switch out the filter a month sooner than you would for a home without pets. The same applies to cats, although they don't shed as much as dogs. If you own a hypoallergenic or non-shedding dog or cat, you might not have to replace your air filter as often.
Although a good rule of thumb, you will need to check your air filter more regularly to determine if it needs to be exchanged. Dogs don't shed at the same rate all year. They shed more in the spring and fall when they are blowing their coat. Check the air filter each month and change it when it looks clogged.
Here are averages that might help you understand how regularly you should get a new air filter at your residence:
- Vacation house or an individual occupant and no pets or allergies: every 6–12 months
- Common suburban home without pets: every 90 days
- A single dog or cat: every 60 days
- More than one pet or if anyone has allergies: 20–45 days