How often you should change the air filters might be on the following:
- Air filter design
- Total indoor air quality
- Number of pets
- Household size
- Air pollution levels and construction around the residence
- Your MERV Rating
For basic 1"–3" air filters, brands usually ask you to change them every 30–90 days. If someone in your family suffers from mild to moderate allergies, you could install a better air filter or change them even more frequently.
The quick answer to "how often do I have to change the air filter?":
If you don't have a smoker or pets at 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?
Some air filters are supposed to last up to six months, while others need to be changed month-to-month. The denser the air filter, the longer it will last. Overall, you can look at the thickness of the filter rather than the brand. You also need to look at the MERV Rating.
The MERV Rating is a scale that records from 1-20 and measures how efficiently an air filter will remove particles from the air. The higher the MERV Rating, the smaller the particle that could be caught by your air filter.
While a filter with a higher MERV Rating should last longer, it could also restrict the ventilation in your home. And you will need to replace the filter more regularly. And if you own an older piece of equipment, plan to change the filter more regularly to maintain the quality of your filter.
How often do I need to substitute my air filter based on thickness?
The lifespan of an air filter also counts on its thickness. A 1" filter will need to be changed out more often versus a 4" filter.
- A 1" pleated air filter ought to be changed every 30-60 days.
- A 2" pleated air filter should be switched every 90 days.
- A 3” pleated air filter ought to be changed out every 120 days.
- A 4" pleated air filter ought to be replaced every 6 months.
- A 5” or 6" pleated air filter must be changed out every 9-12 months.
One of the perks of denser filters is not only do they last longer, but they also boast a higher MERV Rating. This means they will do a better job of getting rid of the particles inside your home. They also produce less air resistance, which can help an HVAC system function more proficiently and decrease strain on components including the blower motor.
If you own a whole-home air purifier, you will also need to switch out the filters more often.
How frequently should I replace my air filter if I want a dog or cat?
If you want pets, you might need to exchange your air filter more often. Pet hair and dander can rapidly clog an air filter and limit its effectiveness. For every shedding dog you have, expect to exchange the filter a month earlier than you would for a home with no pets. The same goes for cats, although they don't shed as heavily as dogs. If you have a hypoallergenic or non-shedding dog or cat, you might not need to replace your air filter as frequently.
Even though it's a good rule of thumb, you will need to check on the air filter more regularly to figure out if it has to be replaced. Dogs tend not to shed at the same rate year-round. They shed more in the spring and fall when they are blowing their coat. Inspect the air filter each month and exchange it when it looks clogged.
Here are averages that can help you learn how frequently you should install a new air filter at your residence:
- Vacation house or one occupant and no pets or allergies: every 6–12 months
- Common suburban home without pets: every 90 days
- A single dog or cat: every 2 months
- More than one pet or if somebody has allergies: 20–45 days