How frequently you need to replace your air filters might be on the following:
- Air filter style
- 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, brands normally instruct you to swap them every 30–90 days. If someone in your family suffers from light to moderate allergies, you could put in a better air filter or exchange them even more frequently.
The shortest answer to "how frequently do I need to switch out my air filter?":
If there isn't a smoker or pets at home, and your filter is the often 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 styles survive longer?
Some air filters are manufactured to last up to six months, while others need to be swapped month-to-month. The thicker the air filter, the longer it will last. Generally, you should examine 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 measures how effectively an air filter can pull particles from 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 can last longer, it might also restrict the circulation in your home. And you will have to change the filter more regularly. And if you have an older system, plan to exchange the filter more often to maintain the life of your filter.
How regularly do I have to switch out 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 instead of 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 must be replaced every 120 days.
- A 4" pleated air filter should be exchanged every 6 months.
- A 5” or 6" pleated air filter should be swapped every 9-12 months.
One of the perks of thicker filters is not only do they live longer, but they also boast a better MERV Rating. This means they should do a better job of filtering out the particles inside your home. They also produce less air resistance, which can help an HVAC system work more efficiently and limit strain on components including 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 replace my air filter if I want a dog or cat?
If you own pets, you might need to switch out your air filter more often. Pet hair and dander can easily 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 in a home without pets. The same is true of cats, although they usually do not shed as often as dogs. If you have a hypoallergenic or non-shedding dog or cat, you might not need to exchange your air filter as much.
Despite being a good rule of thumb, you will need to examine your air filter more frequently to determine if it should be swapped out. Dogs tend not to shed the same amount 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 can help you know how often you should get 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
- One dog or cat: every 2 months
- More than one pet or if someone has allergies: 20–45 days