How Often Should You Change Your Air Filter?

Changing your air filter on a regular basis can prolong the life of your HVAC system and keep your monthly energy bills manageable.

On the other hand, never (or infrequently) changing the filter can lead to expensive repairs, breakdowns and higher electricity costs.

So, how often should you be changing your air filter?

For standard 1” filters, we recommend changing the filter once a month when you’re using your AC, furnace or heat pump on a daily basis. During milder seasons, you can replace the filter once every 6 weeks or every 2–3 months.

That said, there could be some situations where you should change your air filter more often. We’ll look at those situations below.

Have air filter questions? We’re happy to answer them.

If the following situations apply to you, you may need to change your air filter more often than once a month.

• Members of your family have allergies or asthma
• You have pets in the home with dander or who shed
• You’re conducting home projects that create dust and dirt, or there is major construction going on around your home

On the other hand, if you have a thicker air filter (2” or greater), you may not have to change your filter as often because those generally last longer. Consult with an HVAC pro to determine how often you should change more advanced filters.

If you haven’t checked on your air filter in a while, the best time to check on it is today. Just by looking at the air filter, you’ll know if it needs to be replaced.

Don’t remember where to find your air filter or how to replace it? We’ll walk you through the steps below.

Step #1: Locate the filter

• Most air filters are located behind the return air vent. Depending on the size of your home, you may have more than one return vent, which means you have more than one air filter.
• If you are unable to find your air filter, contact an HVAC pro for assistance.

Step #2: Visually inspect the filter

• Unscrew the return grille to access the air filter.
• If the filter looks brown, dingy or it’s clearly dirty and full, it should be replaced.

Step #3: Get a replacement filter

• Look on the side of your old filter and you should find the dimensions of the filter (for example, “20 x 20 x 1”).
• You can purchase a replacement filter at any home improvement store.

Step #4: Carefully remove and replace the filter

• If the area around the filter is especially dusty, you may want to wipe it down with a cloth.
• Fit the new filter into the slot by following the direction of the arrows on the side of the filter. (Make sure the arrows point towards your HVAC system—not towards the house. If you slot the filter incorrectly, the filter won’t capture particles properly and you’ll put extra strain on your HVAC system.)

Our technicians have the answers. We have been serving homeowners in greater San Antonio since the mid-1970s, which means we’ve serviced all kinds of HVAC systems. No matter what type of system you have, we can answer any questions and perform any needed air conditioner, furnace or heat pump service.