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How Often Should I Change My AC Filter? A Minneapolis-St. Paul Tech Answers

One of the most important things you can do for your HVAC system, and yourself, is to change the air filter on a regular basis. Your air filter collects dust and debris that circulate in your home’s air, which improves the overall air quality of your home.

So, how often should you change your AC filter? In general, it’s recommended that you change your filter every 30 - 90 days. That being said, some filters tend to get dirtier faster and need to be changed more frequently than others.

In this blog, we’ll go into more detail about why it’s important to change your air filter and how you can more accurately determine when it’s time to change your AC filter.

Need a pro to help you change your AC filter? That’s what we’re here for.

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Why is it important to change your air filter?

Replacing your air filter before it becomes clogged is crucial to keeping your AC system operating at peak performance.

A clogged AC filter can cause issues such as:

  • Higher energy bills - A clogged air filter will reduce the amount of air to your system, meaning your AC has to work longer and to cool the same amount of air. The longer your AC has to work, the more energy your system consumes and the higher your energy bills will be.
  • Poor air quality - A clogged air filter lets all the dust and debris it should be capturing flow into your air ducts. Eventually, the dirt accumulates in your ducts, which decreases the air quality in your home.
  • Frequent breakdowns - As we mentioned, a clogged air filter makes your AC system work harder and longer, which puts a strain on the system. Eventually, this can cause your unit to break down earlier and more frequently than it should.

How to know when to change your AC filter

As we mentioned earlier, some filters tend to get dirtier faster than others. The more effective an air filter is at catching debris, the more often it needs to be replaced. An air filter’s effectiveness is measured by something called MERV (Minimum Efficiency Reporting Value), which tells you how efficient it is at capturing particles in the air. A higher MERV means your air filter is highly efficient and will need to be replaced more often, whereas low-MERV filters last longer because they don’t collect as many particles as high-MERV filters.

Here are some more specific guidelines for replacing your AC filter based on its MERV rating:

  • MERV 1–4 filters: Every 3 months (or every other month during the summer)
  • MERV 5–8 filters: Every 1–2 months (or monthly during the summer)
  • MERV 8+: Check every month and replace if dirty

Note: These recommendations assume your air filter is less than 2 inches thick. If you have a filter that’s thicker than 2 inches (which is recommended for most MERV 8+ filters), you can usually wait longer to replace your filter.

If you’re not sure what MERV rating your current filter has, just check the side of the filter for a MERV rating label. Most manufacturers will include the MERV rating and dimensions of the filter on the long side of the filter.

Often times, instead of just saying “MERV 5” the filter might just say “M5”.

Other factors that affect how often to change your AC filter

If you’re wondering whether you need to change your air filter more often, just ask yourself the following questions:

Do you have pets?

Cat and dog owners know all too well that pet hair and dandruff can build up quickly, and can get worse as the seasons change. If you’re a pet owner, you should change your air filter every 2 months, especially during season changes (when winter turns to spring and summer turns to fall).

Does anyone in your home have asthma or suffer from allergies?

The Allergy and Asthma Foundation of America (AAFA), has indicated that indoor air quality is just as important as outdoor air quality. If anyone in your home suffers from asthma or allergies, you’ll want to change your AC filter every 6 weeks.

What’s your weather like?

The warmer the weather, the more often you’ll need to change your air filter. The longer your AC runs, the more air will be sucked through your air filter. More air passing through your filter means more trapped contaminants, causing the filter to clog faster.

Need AC filter advice from a Minneapolis-St. Paul pro? We’re happy to help!

We’ve been serving the Minneapolis-St. Paul area since 1918! So, if there’s anyone who understands and appreciates the importance of having good air quality in your home, it’s us. Whether you’re looking for an AC filter installation or just need help to figure out which filter is best for your home, we’ve got you covered.

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