Believe it or not, your air conditioning unit can play a role in whether you feel hot or cold indoors. Your AC filter is responsible for trapping dust, pollen, and other allergens that can cause allergies and other symptoms like sneezing, coughing, and runny nose. Unfortunately, the AC filter can also become clogged with dirt, leaves, and other debris over time.
What is an AC Filter?
AC filters are a must-have for any air conditioning system. They help to remove contaminants and dirt from the air, which can improve the efficiency of your AC unit. When to change your AC filter depends on the type of filter and how often it is expected to be replaced. Here are some general guidelines:
If your AC unit has a pleated or paper filter, it should be replaced every 3 months with a highly efficient 17x21x1 filter.

If your AC unit has an electronic air cleaner, it should be replaced every 6 months or every season, whichever comes first.
AC Filter Change: How to Do It
When it comes time to change your AC filter, there are a few things you should know. First, the AC filter needs to be replaced every 6 months under normal conditions. If your home has high humidity levels, the filter should be replaced every 3 months. Second, if your air conditioning is not working properly, check the AC filter first before calling a professional. Third, always unplug your AC unit before changing the filter. Fourth, disconnect all electrical cords from the AC unit before beginning any work.

Fifth, use a qualified technician when changing the AC filter. Sixth, always wear protective gear when handling an electric power tool and avoid touching metal objects while working with insulation materials. Seventh, allow enough time for installation so that the new filter can fully pre-condition your home’s air conditioning system prior to use. Eighth, call an HVAC technician if you have any questions about how to change your AC filter or if your air conditioner is not working correctly.
When is it time to change the AC Filter?
A good rule of thumb is to check the filter every year, or when the unit starts making strange noises. But there are other factors you should consider when deciding when to replace your AC filter. Here are three:
1. Air Quality: If you live in an area with high levels of pollution, it’s a good idea to replace your filter more often. Polluted air can damage the filter and reduce airflow efficiency, so it’s important to keep your system clean.
2. Age: If your AC unit is 10 years old or older, it’s recommended that you replace the filter at least once a year. Over time, the filters will become degraded and less effective at filtering out particles and contaminants.
3. Size of Unit: The larger the AC unit, the more often it’ll need to be replaced its filter due to increased airflow demands. Units up to 1000 cubic feet require replacement every 3 months, while units over 3000 cubic feet need replacement every 6 months.