Guide to Cleaning and Maintaining Your HVAC Air Filter

By Anne Fonda

For many homeowners, the HVAC system is located in a basement, crawl space, or closet where it’s out of sight, out of mind. If you’re in a new home, read this article about how to find the air filter in your HVAC system.

 While you clean your home and wash your car regularly, you need to take the same care when it comes to filter maintenance and your HVAC system. 

You should know that the terms furnace filter, air conditioner filter, and heat pump filter all refer to the same thing. Filters can be located in many spots throughout the home.

This guide will give you tips and instructions on how to clean an air filter and how to know when it’s time for air filter replacement.

A clean HVAC filter is essential to your HVAC system operating most efficiently. When filters are not replaced, dirt and debris build up can result in a series of issues like decreased airflow that compromise your comfort and increase energy costs. But besides that, air filters help maintain healthy indoor air quality (IAQ). They filter out allergens and pollutants. 

Changing your HVAC air filter is a relatively simple task that can have big benefits. Skipping this routine maintenance task can cause big problems.

You may have seen the acronym MERV when shopping for furnace filters. It stands for Minimum Efficiency Reporting Value. A MERV rating tells you about the filter’s ability to capture particles of various sizes, measured in microns. The higher the MERV rating, the better the filter is at capturing the smallest pollutants from the air which can be the most difficult to capture yet the most damaging to health.

However, there is a trade-off. As the MERV rating increases, the filter adds airflow resistance that may impact HVAC system performance. Most HVAC systems can accommodate air filters with a MERV rating of 8-13. Contact a reputable HVAC company for expert advice on the best MERV rating for your system. 

HEPA stands for high-efficiency particulate air (filter). A HEPA filter is a pleated air filter and can remove at least 99.97% of dust, pollen, mold, bacteria, and any airborne particles with a size of 0.3 microns. 

The answer is, it depends on your filter and whether you have an air purification system. How often to change an air filter will depend on filter type, usage, and environmental factors.

Plan on changing a standard 1” filter at least every 90 days. You may want to switch to changing it every 30 days if you have high system usage, allergies, or pets. You may also want to consider upgrading to a better filtration system.

For example, a thicker, high-efficiency filter such as the Trane QuikBox™ Air Cleaner only needs to be changed every 6 months, but should be changed sooner if you notice signs of a dirty or clogged filter.

For the ultimate in filtration and convenience, the reusable filter in the Trane CleanEffects® Whole Home Air Cleaner should be cleaned every 3-9 months depending on usage.

You may want to change an HVAC filter more often than recommended if you’re experiencing heavy usage of your HVAC system, such as during summer heat waves or extended winter cold snaps. 

There are several signs of a dirty or clogged filter you should be aware of.

• Your programmable or smart thermostat says it’s time to change/clean the filter.
• It looks dirty/fuzzy.
• Family members are sneezing or coughing and showing allergy symptoms.
• You notice your house is more dusty.
• Your energy bills are creeping up with your usage saying the same.

A dirty or clogged air filter can negatively affect indoor air quality, but it can also put a strain on your HVAC system. Replace or clean dirty or clogged filters ASAP.

Whether you clean an air filter or replace it will depend on the specifics of your system and what type of filter you have.

Follow the manufacturer’s directions for cleaning a reusable air filter that’s part of a whole-house air cleaner. Following are basic directions for cleaning the  Trane CleanEffects® Whole Home Air Cleaner. 

1. Turn the HVAC system off.
2. Turn off the power to the air cleaner.
3. Wait 15 seconds.
4. Disconnect the power cable.
5. Rotate the latches and remove the door.
6. Remove the pre-filter and/or collection cells.
7. Using a vacuum hose with a crevice attachment, gently vacuum the pre-filter and collection cells.
8. Replace the pre-filter and/or the collection cells.
9. Reconnect the power cable.
10. Reattach the door.
11. Turn the air cleaner back on.
12. Turn the HVAC system back on.

Refer to your owner’s manual for more detailed information, including diagrams. An HVAC technician can also do this for you during a maintenance visit.

If you have a ductless mini-split system, you also have reusable, cleanable air filters. Our single-zone ductless systems and multi-zone ductless HVAC systems have durable, washable air filters that can last as long as 10 years, and save you money on filters!

If you have a mini-split, here is how to clean the air filters.

1. Turn off the mini-split.
2. Open the unit by lifting off the panel.
3. Gently remove the air filters, being careful not to shake off dust during removal.
4. Unclip the smaller enzyme filters from the larger ones. These smaller filters should not be allowed to get wet.
5. Vacuum and/or rinse the large air filters. Using a brush attachment and low suction, vacuum the filters.
6. If you see any remaining dust or debris, gently handwash the filters in your sink. Use lukewarm water and the spray attachment on your faucet for best results.
7. Allow the air filters to thoroughly dry.
8. Snap the enzyme filters back on.
9. Replace the filters in the mini-split once they are dry.
10. Close the panel.
11. Turn the mini-split back on.

For further guidance, refer to your owner’s manual.

Disposable HVAC air filters are called that for a reason. They are not meant to be cleaned and reused. If you try to wash a disposable filter, dust, dirt, and other contaminants can stay behind in the folds of the filter material. In addition, your attempts to clean the filter will likely damage it. 

If you try to reuse a disposable air filter, you risk decreasing your HVAC's efficiency and straining the motor. Failure to properly maintain your system could also result in a loss of warranty coverage.

Instead, replace a disposable filter every 30-90 days, or more often during pollen season or heavy HVAC usage. 

By replacing or cleaning your HVAC air filter regularly (as recommended by the manufacturer), you reap several benefits.

1. Improved indoor air quality and respiratory health
2. Reduced allergens, dust, and pollutants in your home
3. Energy savings and increased HVAC system lifespan

If you need help remembering when to change or clean your air filter, consider adding a calendar alert to your phone. You can also invest in a smart thermostat, which will give you reminders when it is time for filter maintenance. 

For compatible systems, the Trane Home App can be a lifesaver. It allows you to schedule filter reminders and even order filters directly from the App. Set up filter reminders in the “settings” pane of your Trane Home app, and when it is time to change your filter, you will receive a reminder and a prompt to purchase one--simple!

If you use standard air filters, consider buying them in bulk to save money as well as ensure you have a spare filter on hand when you need it. One of the most frequent questions we get about filters is “What size filter do I need?” Get the answer to that question and more by reading our Filters FAQs. Check the existing filter to ensure you get replacement filters in the right size.

Trane Filters powered by FilterTime is a filter fulfillment service that makes your life easier by delivering high-performance HVAC filters straight to your door with free shipping. We have multiple air filter sizes to fit most HVAC equipment brands.

By using the Trane Home App or visiting TraneFilters.com, you can make a one-time filter purchase or sign up for ongoing subscription options. No matter which you choose you’ll get the quality and innovation you expect from Trane with a full range of filter sizes. Our high-quality 1” filters are tested to meet or surpass our rigid performance criteria, with electrostatically charged fibers that efficiently capture microscopic airborne particles. 

Have questions about the best air filters or upgrading to a home air purification system? Contact your local Trane Comfort Specialist for expert advice. They can offer a customized evaluation of your heating and cooling system and make personalized product recommendations.

Anne Fonda, Content Writer

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A Content Writer with Trane Technologies, Anne Fonda researches topics and writes for Trane® and associated residential HVAC brands. She works in collaboration with Trane Technologies subject matter experts, offering easy-to-understand, informative content on complex topics. Her goal is to help consumers make informed decisions on the products and services they need.

She has written for HVAC and other service provider websites for over 16 years. Before transitioning to web content writing, Anne had a 14-year stint as an award-winning journalist. She graduated cum laude from the University of Missouri-Columbia School of Journalism.

When she’s not working, Anne enjoys playing word games, reading, gardening, spending time with family, and visiting gardens and museums.

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