How regularly you should change the air filters can depend on the following:
- Air filter design
- Overall indoor air quality
- Quantity of pets
- Household size
- Air pollution levels and construction nearby the residence
- Your MERV Rating
For common 1"–3" air filters, companies typically instruct you to exchange them every 30–90 days. If someone in your family suffers from mild to moderate allergies, you could use a better air filter or change them even more regularly.
The quick answer to "how frequently do I have to exchange my air filter?":
If you don't have a smoker or pets in the home, and your 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 replacing it.
What air filter brands survive longer?
Many air filters are designed to survive up to six months, while others have to be changed month-to-month. The larger the air filter, the longer it will last. In general, you should check 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 assesses how well an air filter can remove particles out of 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 should last longer, it may also restrict the flow of air in your home. And you will need to replace the filter more often. And if you own an older system, plan to substitute the filter more often to conserve the quality of your filter.
How regularly 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 changed out more frequently versus a 4" filter.
- A 1" pleated air filter must be replaced every 30-60 days.
- A 2" pleated air filter should be swapped out every 3 months.
- A 3” pleated air filter should be switched every 4 months.
- A 4" pleated air filter must be changed out every 6 months.
- A 5” or 6" pleated air filter ought to be replaced every 9-12 months.
One of the perks of thicker filters is not only do they survive longer, but they also posses a higher MERV Rating. This means they will do a superior job of filtering out the particles within your home. They also produce less air resistance, which can help an HVAC system work more efficiently and decrease strain on components such as the blower motor.
If you want a whole-home air purifier, you will also have to switch out the filters more often.
How often should I change my air filter if I have a dog or cat?
If you have pets, you might need to replace your air filter more regularly. Pet hair and dander can rapidly clog an air filter and reduce 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 usually do not shed as often as dogs. If you want a hypoallergenic or non-shedding dog or cat, you might not need to exchange your air filter as frequently.
Even though it's a good rule of thumb, you will need to examine your air filter more frequently to determine if it has to be replaced. Dogs usually do not 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 monthly and exchange it when it looks clogged.
Here are averages that may help you understand how regularly you should install 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 90 days
- A single dog or cat: every 60 days
- More than one pet or if a member of your family has allergies: 20–45 days