BMI Mechanical Heating, Ventilation and Air Conditioning
BMI Mechanical Heating, Ventilation and Air Conditioning

Your Simple Guide: How often to change air filter

▸ July 7, 2021

Many people want to know, “How often should I change my air filter?” 

Does it really make a difference if I replace it once every 6 months as opposed to once every 3 months?

The answer to this question is yes. It does make a difference, and here’s why:

  • You can reduce repairs: Your air filter collects a lot of things over time (pet dander, dirt, etc), and it usually turns “dusty” or “grey” as a result. If you allow your filter to be dirty like this for long periods of time, it can have a negative impact on your HVAC and its components. This will ultimately lead to more repairs (and more bills).
  • You can save money: Yes, you can save money on repairs by doing an air filter change at the right time, but you can also save money on your heating and cooling bill. Your HVAC won’t be able to work properly with a dirty air filter — instead, it has to work much harder. You can guarantee that this hard work will be showcased in your next energy bill.
  • You can improve your IAQ (indoor air quality): Whether you have allergies or not, it doesn’t matter. If your air filter can’t do its job properly, you’ll eventually be breathing in a whole lot of stuff that’s not great for your body. 

Now that we better understand why it’s important to change out the air filter, let’s talk about how often to change the air filter.

How often should you change your air filter?

There are a handful of factors that can impact the question of how often to change the air filter. These factors will vary from home to home and from business to business. This ultimately means that every building should be doing an air filter change at different times.

If you’re in a commercial or industrial setting that requires a more particular air filter, we recommend discussing air filter changes with your HVAC partner. In these cases, a licensed HVAC contractor is almost always required in order to remove the air filter safely and correctly. 

However, if you’re dealing with a more standard office or home air filter, then an air filter change is usually recommended every 2 to 3 months. 

In some cases, this timeframe could be extended to as much as 6 to 12 months, but this really depends on the inner workings of the office or home. Factors that can affect how often you change out your air filter can include:

  • The type of air filter you’re using
  • If there are pets indoors
    • What type and how many
    • Typically means every 1 to 3 months
  • How big the building is
    • The larger the building, the more air filter changes recommended
  • What the outdoor environment is like
    • Heavily polluted cities means more air filter changes
  • If the occupants suffer from allergies or breathing-related issues (like asthma)
    • Typically means every 1-2 months
  • How often the building is occupied and how many people occupy it
    • Is it a vacation property? (lowers the amount of changes in comparison to a permanent residence)
    • Is there only 1 person in the office at a time? (lowers the amount of changes in comparison to a busy office environment)

Keep Reading: Take a look at 5 summer HVAC issues 

If you still don’t know when to change your air filter, here’s what we recommend.

If you’re still not sure how often to change your filter, then a good timeframe to live by is every 60-90 days. 

If you don’t have any pets and you live in a city with no heavy pollution, then you can stretch it to 90 days. If you do have pets, live in a heavily polluted city, or have occupants with allergies or breathing issues, then you should (at least) be replacing your filter at the 60-day mark.

If you’re in a work environment and you have employees or coworkers to worry about, then we suggest speaking with a commercial HVAC contractor. In traditional office environments, we would still recommend every 60-90 days, but this can change depending on your HVAC and your specific needs and habits.

Long story short: changing your air filter does make a difference. One simple task can help keep your HVAC unit working properly and your indoor air quality at a good level.

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Commercial tenants who experience 3 annual interruptions to HVAC service have a 56% probability of not renewing their lease. If they also have problems dealing with building management, that probability increases to 80%. BOMA

When the service professionals at BMI Mechanical focus on what they do best, we are able to focus on what we do best. For over 6 years Patterson Logistics Services has trusted the folks at BMI to keep our building temperatures within the desired range. In today’s business world we need to partner with companies like BMI whose tradition is built on honesty and integrity. BMI, thank you for taking care of business! Cesar Lopez PLSI Western Distribution Center Manager Patterson Logistics Services