What Does Your Air Conditioner’s Air Filter Really Do?

As a homeowner, you might think of changing your air conditioner’s air filter every few weeks as just another part of routine home maintenance and upkeep. However, have you ever really taken the time to think about your air filter and what it really does? If not, you might be surprised to learn just how important it really is.

What Is an Air Filter?

Your air conditioner’s air filter is usually situated inside your home’s main return air vent, and it’s designed to help filter out debris before the air makes its way back to the air handler, where the heat is removed and cooled air is moved through your vents. Air filters can be made of several different materials, ranging from incredibly inexpensive paper and cardboard to more expensive materials like fiberglass or even polyester. The differences in these can vary, but in most cases, the more expensive filters are able to capture even the smallest particles. This includes not only dust, but also allergens like pollen and pet dander, which keeps them from recirculating throughout your home.

What Happens if the Filter is Dirty

While it’s likely not a big deal if you forget to change your filter for a couple of days, leaving a dirty filter in place – or failing to use a filter at all – can wreak havoc on your air conditioner and even your health. All the following issues can arise when you use a dirty filter or no filter at all.

  • Reduced airflow. Because the filter is located just inside your return air vent, it needs to be clear so air can pass through and get to the air handler. When your filter is clogged with debris and dust, the system cannot pull air through to the air handler as easily, which can restrict airflow through your registers, as well. This can impact not only your comfort, but also the efficiency of your unit.
  • Buildup in your ducts. If your air filter is dirty, then everything behind that filter is also dirty, and this includes your ducts. As your unit pulls air into the air handler, it then blows this air back through your home through a series of ducts. If that air is laden with dust, dander, and other debris, those particles will stick to the inside of your ducts over time. This can create health issues, especially for people with breathing disorders and allergies.
  • Air conditioner failure. All air conditioners are designed to work with a certain amount of airflow. If your unit isn’t getting the air it needs due to a dirty filter, it may simply malfunction, leading to costly repairs – or even the need to completely replace your unit.
  • Huge energy bills. Finally, a dirty air filter makes your unit work incredibly hard to cool your home. With less airflow, and with less cool air finding its way through your registers, your air conditioner will have to run much longer than normal to produce the same amount of cooling. This can cause your energy bills to increase by as much as 50%.

Changing your air conditioner filter is very important, as is choosing the right quality filter as recommended by the manufacturer of your air conditioner. If you’re not sure which filters to use – or how often to change them – contact your local HVAC technicians with your unit’s brand and model number for more information.