Should I Be Changing My HVAC Filter More Often as the AC Runs?

It’s hot out every day, which means that your AC is probably running all the time – certainly more than it has in the past few months. During a heat wave like this, our air conditioners put in a lot of work, and that means that a lot of air is going through our air filters.

Clogged air filters can cause all sorts of problems, not only for your air quality, but also for your HVAC. If you’ve been forgetting to switch out your air filter, you probably need to.

But do you need to switch out your air filter more often when your air conditioner is running 24 hours a day?

The answer is a resounding “maybe!”

The Importance of Regular HVAC Filter Changes

The HVAC filter plays a vital role in maintaining indoor air quality and system efficiency. It traps dust, pollen, pet dander, and other airborne particles, preventing them from circulating through your home. Regularly changing the filter is essential for several reasons:

• Improved Air Quality – Clean filters ensure that the air circulating in your home is free of pollutants, benefiting your respiratory health.
• System Efficiency – A clean filter allows for better airflow, reducing strain on the HVAC system and improving energy efficiency.
• Longevity of the System – Regular filter changes prevent dirt and debris from accumulating on internal components, reducing wear and extending the lifespan of the system.

We often forget that the air filters in our HVAC system are one of the best tools we have to prevent allergies, remove particles, and more. It’s why it is recommended that you always run your fan, even when your AC is off, to make sure that you’re continuing to filter the air.

Which is why your AC running all the time is not likely to make much of a difference in the filter. Most people expect to have their fans running at least close to 24 hours a day, and the air conditioner itself is still pushing the same air through the system – thus, it is not terribly different from other times of year, and shouldn’t require a change in HVAC frequency.

Factors Influencing Filter Change Frequency

However, there are situations where you may still need to change your air filter more often during heat waves and periods of heavy use. These include, but are not limited to:

• Running Your Fan – When we say “more often” that is entirely dependent on how often you switched it before. If you rarely switched out your air filter or you didn’t run your fan, chances are you are going to need to switch it out more often than you’re used to.

• Sensitive Air Conditioners – Similarly, if your AC system is sensitive to clogged filters, and you need/want your AC to work correctly, you may need to replace it a bit more often to make sure that it keeps running.
• Household Environment – Homes with pets, smokers, or individuals with allergies may require more frequent filter changes due to higher levels of airborne particles. If you’re spending more time indoors as a result of the heat, this could mean that you need to replace your filter fairly frequently.
• Filter Type – Different filters have varying lifespans. Standard fiberglass filters may need to be changed every 30 days, while higher-quality pleated filters can last up to 90 days or more.
• Outdoor Air Quality – Areas with high levels of pollution or pollen may necessitate more frequent filter changes to maintain indoor air quality. Here in Sacramento, our biggest issue is going to be smoke from fires. During fire season on hot days, you will need to switch your air filter out frequently.
• Windows Open/Doors Open – Even though it’s hot, many people find that they are spending time outdoors. Often, that means opening windows or doors. As your AC runs, it may be drawing in allergens and debris from the outdoors, which in turn means that your HVAC filter fills up faster.

So, although air filters typically have the same lifespan (as the fan tends to run all the time anyway), there are many issues that occur during heat waves and hot summers that may mean you have to replace your filter more often.  

Signs That It’s Time to Change Your Filter

Even with a general understanding of when to change your filter, you should also be checking it and your AC for signs that a replacement is necessary. These include:

• Visible Dirt and Dust – If the filter appears dirty or clogged, it’s time for a change.
• Reduced Airflow – A noticeable decrease in airflow from your vents can indicate a clogged filter.
• Increased Energy Bills – A sudden spike in energy costs may suggest that your HVAC system is working harder than necessary due to a dirty filter.
• Allergy Symptoms – Increased allergy symptoms among household members can be a sign of poor air quality, often due to a clogged filter.

To ensure your HVAC system runs efficiently and effectively, inspect your filter every 30 days, especially during periods of heavy AC use, use calendar reminders or HVAC maintenance apps to help keep track of when it’s time to change the filter, and select a filter that matches your system’s specifications and meets your household’s air quality needs.

If you need more personalized advice based on your home and the quality of your air filter, please let us know. During our annual tune ups, we can take a look at the filter, the system, and more, and see if there are any reasons to speed up how often your filter gets replaced.

ACs, Heat Waves, and Air Filters

The answer to whether you need to change your air filter more often is a complicated one. Likely, you do not. Your air filter has the same speed that it always has, which means loosely the same amount of air should flow through it.

But there may be more particles inside and outside of your home, or you may have an air conditioner that is sensitive to air filters that do not have adequate airflow. Your home may also heat up if you do not have air that is able to flow freely. All of these means that you may need to replace your air filter more often. For more personalized support, please contact Cal Energy, today.