How Often Should You Clean Your HVAC Filters?

Learn how often you should clean your HVAC filters for maximum efficiency! We explore all factors that influence how often you should replace or clean your HVAC filters.

How Often Should You Clean Your HVAC Filters?

When it comes to keeping your HVAC system running efficiently, one of the most important things to consider is how often you should clean your air filters. According to, the ideal is to change your air filter every three months. However, there are certain factors to consider when determining when to change an old filter. A good rule of thumb is to check your filter every month.

As a general rule, you should clean the air conditioner filters inside the indoor unit every two weeks. In dusty or polluted environments, you should clean the filters more regularly. Be sure to vacuum the floor and use a dustpan on a regular basis. This will prevent the filter from clogging.

To maintain the health of your air conditioning system, you must schedule maintenance twice a year. If you want your air conditioner to operate at maximum efficiency, you should change the filter every few months. HVAC filters should be changed at least once a month in companies that produce a lot of dust and debris. Filters need to be replaced before they become too clogged to work. Clean filters can extend the life of your HVAC system for many years. The Trane system will tell you when it needs to be cleaned, but in general, you should vacuum the filter every one to three months.

Clean more often if you suffer from allergies, smoke, or have furry pets. Trane recommends that a technician perform a more thorough cleaning of additional components. For more information, watch this Trane video on Clean cleaning methods. We are going to explore each of these factors. This is by far the most important factor: The filter collects dust and debris only when the system is operating.

The more it works, the faster the filter picks up dirt. During a bitter cold Minnesota winter, a furnace filter will need to be changed more often than during a mild Missouri winter. On the other hand, you will need to change the filter more frequently during a hot and humid Missouri summer than during the Minnesota summer. Remember that a filter also gets dirty during AC mode. Do you find pet hair in your oven filter? Hair fibers from dogs, cats, rabbits and other mammals are large compared to dust and dirt that normally trap the filter.

That means they clog the filter and block the airflow pretty quickly. The more important clean air is, the more often the filter needs to be cleaned or changed. A coarse-media filter, MERV 11 or higher, or an electronic air filter is the best option when someone in the household has asthma, severe allergies, or difficulty breathing for any reason. The air will be cleaner than if a basic fiberglass air filter is used. You may also want to consider an air cleaner for your system.

Our Air Purifier Guide contains comprehensive information on all types, including electronic and media air filters, how they work, which is best for your purpose, and more. Cheap fiberglass filters require less frequent replacement than pleated filters. Some sites get this exactly the other way around, claiming that thicker filters can last longer between changes. That goes against the design of the filters. Coarse-media filters trap more and smaller dust particles, so they obviously clog up faster. Slim fiberglass filters don't trap as much dirt and debris, so they don't clog up as quickly.

The good news is that some of those filters can be cleaned with a nylon brush and placed back in the oven or air controller instead of replacing them. Cleaning should be done outside or in a garage to keep dust and dirt out of your home. If removing dirt with a brush instead of replacing the media filter, be sure to change the filter after two or three cleanings. In the end, brush cleaning will not remove enough deeply embedded dirt and debris. In larger homes, more air flows through the filter than in smaller houses.

Because the air carries dust, pet hair, and other debris, the filter will get dirty more quickly in a system that serves a large house. Some of you wonder what we mean by continuous fan mode and why a homeowner would use it. There must be a setting in the thermostat such as Auto and Fan options. In automatic mode, the fan works only when the system is heating or conditioning the air in your home. In fan mode it works all the time until you turn it off.

The longer the system works even if it is not heating or air conditioning;the faster the filter will get dirty and it will need to be changed. Is continuous fan mode a good idea? Here are some pros and cons: First off it will cleanse air by passing it through an air filter more often; thus requiring more frequent changes of said filter; second it helps balance temperatures in your home; third if you have a basement you can draw cool air from there to help cool upstairs floors; however running fan requires electricity so electricity bill will increase; second humidity makes uncomfortable in summer so thermostat settings must be lowered; this causes AC work longer resulting in higher electricity costs; in summary continuous fan mode is not recommended as standard operating procedure. Follow these steps to find out when to change your air filter: You should check your filter every month; clean indoor unit's filters every two weeks; clean more often if environment is dusty or polluted; vacuum floor regularly; schedule maintenance twice a year; change filter every few months if AC operates at maximum efficiency; change monthly if company produces lot of dust and debris; use coarse-media or electronic air filters if someone has asthma or allergies; use slim fiberglass filters if possible but clean with nylon brush after two-three times; use continuous fan mode only if necessary but consider pros and cons before doing so.