How Often Should I Replace My Air Filter? A Portland Tech Answers

One of the best things you can do for your HVAC system is to replace your air filter every 1-3 months.

Replacing your air filter regularly can improve the quality of the air in your home, reduce your utility bills and extend the life of your HVAC system.

In this blog, we’ll discuss:

  • Why you need to replace your air filter every 1-3 months
  • How to know when to replace your air filter
  • Exceptions to the 1-3 month rule
  • How to replace your air filter

If you need help changing your air filter, Four Seasons can do it for you. Learn more about the air filter installation services we offer or schedule service.

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Why you need to replace your air filter every 1-3 months

Replacing your air filter every 1-3 months prevents your filter from becoming clogged and keeps your HVAC system running at peak performance.

A clogged air filter can cause issues like:

  • Higher utility bills. A clogged air filter restricts the amount of air that flows through your HVAC system. Low airflow causes your system to work harder for longer periods of time, resulting in a strained system and a higher utility bill.
  • HVAC breakdowns. Low airflow due to a clogged air filter puts stress on your HVAC system and can cause it to overheat. A clogged air filter also allows dust and other particles to collect on your HVAC system, which can damage parts.
  • Poor air quality. If your air filter is clogged, it will allow particles that it normally catches to enter your HVAC system, collect in your ducts and circulate throughout your home’s air. This can significantly reduce your household air quality.

How to know when to replace your air filter

The more efficient your air filter is, the more frequently it should be replaced.

Your air filter’s MERV rating measures how effectively the filter can capture dust. The higher the filter’s MERV rating, the smaller the particles it can trap. However, high-MERV air filters also can clog more easily.

Depending on your air filter’s MERV rating, you should change your air filter:

  • Every 2-3 months for a MERV 1-4 air filter
  • Every 1-2 months for a MERV 4-8 air filter
  • Every month for a MERV 8+ filter

This rule applies to air filters that are under 2 inches thick. That said, air filters that are 2-5 inches thick can be changed less frequently.

While your air filter’s MERV rating can provide an approximate replacement schedule to follow, there are a few exceptions to the 1-3 month replacement rule.

Let’s discuss those exceptions….

Exceptions to the 1-3 month rule

You may need to replace your air filter more frequently or less frequently if:

  • Your air filter is flat. A pleated filter can trap more dust than a flat filter.
  • There are smokers in your home. Because cigarette smoke carries pollutants that can clog up an air filter, you’ll need to replace your filter more frequently if someone in your home smokes.
  • You have a large household. The more people in your household, the more pollutants are in the air. You’ll need to replace your air filter more frequently.
  • You are remodeling your home. If you are remodeling your home, you’ll need to check and replace your air filter more frequently to prevent the added dust and debris from clogging your air filter.
  • You have pets. Pet hair and dander can build up fast on an air filter. You’ll need to replace your air filter more frequently if you have pets, especially when weather changes result in more shedding.
  • Someone in your home has allergies or asthma. You should replace your air filter more frequently to improve indoor air quality for loved ones with allergies or asthma.
  • You live in a warm or cold climate. In a warm or cold climate, your HVAC system has to work longer and harder. Keep your HVAC unit running at peak performance by checking and replacing your air filter more frequently.

How to replace your air filter

  1. Visually inspect the air filter. If your air filter appears brown or dusty, replace it.
  2. Purchase a new air filter. The size is printed on the side of your old filter. You can purchase a new filter at a home improvement store.
  3. Replace the air filter. Fit the new filter into the vent. The arrows that are printed on the sides should point toward the HVAC system. If you put the air filter in backward, it won’t effectively capture dust.

Need help replacing your air filter? Contact Four Seasons.

If you have trouble locating the air filter, are unsure which air filter you need or want advice, Four Seasons is here to help.

When you choose Four Seasons, you will get professional service during every step of your air filter installation.

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