How Often Do I Need to Change My AC Filter?

Filters are an integral part of your air conditioning system. They help to catch dirt, debris, pollen, and other particulates that can circulate through the air of your home, helping to improve air quality. Because they can get dirty quickly, it’s important to change your filter on a regular basis.

Why Are Filters So Important?

The filter on your AC system does more than help keep your air clean. It also keeps particulates out of your AC unit. These particulates could build up inside the unit, causing problems that may require extra maintenance of your AC unit over time.
When your filter gets dirty, it also becomes more difficult for your unit to work. Therefore, the system will work harder to circulate the same amount of air, driving up your energy bills and ensuring your system will need more frequent maintenance.
Changing the Filters
According to Energy.gov, it’s important to change your filter on a regular schedule — typically every one to three months. The exact schedule required varies depending on the type of filter and how much dirt it’s collecting. Some filters will require more frequent changing than others to help keep your system functioning well. To find out the exact schedule for your filter, refer to the manufacturer’s recommendations.

Variations in Filter Schedules

Filter types include fiberglass, polyester, pleated, washable, and high efficiency. Each one filters differently, and therefore will collect particulates differently as well. This means that one system may last slightly longer than another — fiberglass filters, for example, are only designed to protect your system, not to clean your air, and will only remove a small percentage of dirt, meaning they don’t clog up as quickly as polyester or pleated filters do. Your home environment and how many particulates are circulating in the air will play a big role as well.
Homes in areas with high pollen counts or lots of dust or pet hair will probably require more frequent filter changes than cleaner homes. Homes that use separate air filtering systems need HVAC filters changed less frequently than homes that do not.

Checking Your Filter

A good way to find out if your filter needs to be changed is to simply slide it out after a month of use and take a look at it. If it appears visibly dirty, it’s time to change it. If it still appears to be fairly white and clean, let it go for another month and check again.
Some households can get away with checking their filters at the start and end of every season, such as checking right before you turn the air conditioning on in the summer, and again before you turn on the heat in the winter. If you don’t plan to check with your manufacturer, or change the filter on a regular basis, you may want to get into a habit of checking your filters regularly.
Over the course of a year, you should be able to see a pattern develop. For example, you may notice there are times of the year when you need to change the filters more regularly than others. Plan on checking your filters monthly for a year, and writing down your results. This will give you a personalized schedule to follow for the years to come. If you change filters, or notice a drop in HVAC performance, you may need to revise your schedule.

Keep Your System Running Well

By changing your filter on a regular basis, you’ll ensure that your AC system is running as well as it can, while also ensuring that your air remains cleaner. Check and change your filter regularly to make sure your air and system stay clean.