How frequently you should replace the air filters could be on the following:
- Air filter model
- Overall indoor air quality
- Number of pets
- Household size
- Air pollution levels and construction nearby the residence
- The MERV Rating
For standard 1"–3" air filters, companies normally ask you to swap them every 30–90 days. If someone in your family suffers from light to moderate allergies, you can put in a better air filter or replace them even more frequently.
The shortest answer to "how often should I switch out my air filter?":
If you don't have a smoker or pets in your 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 types last longer?
A few air filters are supposed to survive up to six months, while others should be changed each month. The thicker the air filter, the longer it can last. In general, you should 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 goes from 1-20 and assesses how well an air filter will remove particles out of the air. The higher the MERV Rating, the smaller the particle that can be caught by your air filter.
While a filter with a higher MERV Rating will last longer, it may also hamper the airflow in your home. And you will need to change the filter more regularly. And if you acquire an older system, plan to exchange the filter more regularly to conserve the quality of your filter.
How often should I switch out my air filter based on thickness?
The lifespan of an air filter also counts on the thickness. A 1" filter will have to be swapped out more frequently instead of a 4" filter.
- A 1" pleated air filter ought to be changed out every 30-60 days.
- A 2" pleated air filter ought to be replaced every 3 months.
- A 3” pleated air filter ought to be exchanged every 4 months.
- A 4" pleated air filter ought to be exchanged every 6 months.
- A 5” or 6" pleated air filter must be replaced every 9-12 months.
One of the perks of denser filters is not only do they survive longer, but they also posses a better MERV Rating. This means they will do a more effective job of filtering out the particles in your home. They also produce less air resistance, which can help an HVAC system run more effectively and reduce strain on components including the blower motor.
If you have a whole-house air purifier, you will also need to replace the filters more often.
How frequently should I replace my air filter if I have a dog or cat?
If you own pets, you might have to exchange your air filter more often. Pet hair and dander can quickly clog an air filter and limit its effectiveness. For every shedding dog you want, expect to change out the filter a month earlier than you would in a home lacking pets. The same applies to cats, although they usually do not shed as heavily 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 check the air filter more frequently to determine if it has to be exchanged. Dogs usually do not shed the same amount all year. They shed more in the spring and fall when they are blowing their coat. Inspect the air filter monthly and replace it when it seems clogged.
Here are averages that may help you know how frequently you should get a new air filter at your residence:
- Vacation house or one occupant and no pets or allergies: every 6–12 months
- Average 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