How Often Should I Replace My Air Filter in Portland?

Keeping your air conditioning unit in good condition requires regular maintenance. One of the best things you can do for your HVAC system is to replace your air filter every 1-3 months.

Clogged filters slow down airflow and leave gunk in your system. You don't want to gum up the works or have unwanted allergens and other particles blasting through your home whenever the air or heat kicks on. Regularly replacing your air filter improves the air quality in your home, reduces your utility bills, and extends the life of your HVAC system.

In this blog, we’ll discuss:

  • 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

This article will explain how often you should change your filter while considering extra factors, how to make the process easier on yourself, and the benefits of professional HVAC maintenance.

Need Help With Your Air Filter?

If you aren't sure how to safely replace your air filter, call the Four Seasons team at 503-538-1950 or click the button below. Our NATE-certified technicians meet the highest of industry standards and can service every air conditioner make and model. Homeowners in the Portland area rely on us for our 5-star service.

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Replace Your Air Filter Every 1–3 Months

A dirty air filter will make your home dustier than normal

According to the Department of Energy, frequent air filter replacement is a must. Most systems use air filters that need swapping every 1-3 months. More prolonged use means a higher risk of clogs and performance issues with your HVAC system. Replacing your air filter every 1-3 months prevents your filter from becoming clogged and keeps your HVAC system running at peak performance.

If you miss that 1-3 month window, you could be dealing with:

  • Significant electric bills. Clogged filters slow down air passing through, making your system work harder to deliver the same level of cooling. The longer your system runs, the more it costs on your monthly 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.
  • Reduced unit lifespan. When your unit works harder, it wears out faster. Plus, a clogged filter means dust and debris can cause backflow into the mechanical parts of your unit, doing extra damage.
  • Lack of fresh indoor air. High insulation levels already make indoor fresh air a challenge, but you magnify the problem when your air filter isn't working properly. All the dust and allergens that usually get trapped in the filter start circulating through the air you breathe.

Make it a habit to swap out your filters regularly. Adding filter replacement to your calendar is a great way to avoid major problems with your HVAC system.

How To Know When To Replace Your Air Filter

The more efficient your air filter, the more often you need to replace it, but the cleaner your air will be.

Air filters come with a MERV rating that gives you an idea of how well the filter can trap particles. A higher MERV rating means the filter can trap small particles. Very high MERV filter ratings are comparable to HEPA filters used in hospitals to improve air quality for patients with sensitive respiratory systems. However, the downside is that high-MERV air filters also clog more quickly, depending on their thickness.

Most HVAC units have a standard filter installation with a MERV 8 rating. If you're using an 8-MERV filter that is 2" thick or thinner, you'll likely need to replace it every month. You should change an air filter that is 2” thick or less this frequently:

  • 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

Higher-rated MERV filters can also be 2" to 5” thick or more, which extends the replacement time. Some 5-6" filters might not need replacing until the end of a year.

However, with Portland’s wildfire season, the question of when to replace filters is a bit more complex than in other areas. Even with filters that typically last for 6 months or longer, it might be better to replace filters more frequently to maintain your air quality during this season.

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

Certain factors can change how often you replace your air filter.

Many factors might extend or reduce the life of your filters, such as:

  • Flat, fiberglass filters often last 30 days or less, while pleated filters last for three months under normal conditions.
  • If you have pets, you might need to replace your filter monthly—even if it would typically last longer. Pet hair and dander can quickly clog up even the highest quality filter.
  • Smoking is another activity that runs through filters faster. And, of course, wildfire smoke also affects filter lifespan.
  • Larger households mean more frequent open doors and other air pollution, limiting the time you can depend on a filter.
  • 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.
  • Family members with respiratory conditions or allergies also benefit from frequent filter changes. The cleaner the filter, the more allergens it can trap, leaving your indoor air cleaner than the outside.
  • Outside temperatures also affect your filter replacement times. The more your unit runs, the more frequently you need to replace your filters. That could mean replacing your filter monthly during the wildfire season and the peak of summer while using the same filter to get through fall and spring.

How To Replace Your Air Filter

Make sure to change out your air filter if it’s dirty.

First, visually inspect the air filter to make sure it’s brown or dusty. If so, it’s time for a replacement.

When it comes time to replace your air filter, you'll need to ensure you have a compatible replacement. Check the filter currently installed in your HVAC unit. It should have the model number and dimensions listed. Most local hardware stores carry a variety of filter replacement options.

When removing the old filter to install the new one, pay attention to the direction it faces. Air filters have arrows that tell you which direction should face the HVAC unit. If you install the filter backward, it won't work correctly.

If you've upgraded to a wider filter option, you may need help when it comes time to replace your 5" filter.

Not Sure How To Replace Your Air Filter?

Contact Four Seasons for reliable air filter replacements.

If you can't find your filter or you aren't sure about your replacement schedule, get good, old-fashioned service and a helping hand from one of the knowledgeable HVAC pros at Four Seasons. Our annual maintenance package includes air filter installation and guarantees 100% satisfaction.

Call us today at 503-538-1950 for fast, convenient scheduling and a 2-hour appointment window.

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