When Should I Change My Air Conditioner's Air Filter at Home?

February 26, 2015

Need the fast answer? See our FAQ on "How often to change the air filter".  

Every once in a while we’re asked what is the most important thing that Alliance area homeowner's can do to secure their air conditioning and heating system between their seasonal tune-ups? It's a simple question with a simple answer; remember to change the heating and air conditioning air filter. Replacing furnace and return air filters is extremely important to the proper performance of your HVAC system, in addition to your home's air quality. Research suggests that indoor air pollution is one of the top five environmental health risks? You probably don’t consider it as you sit and watch TV, but this is the air you breathe day and night. Changing the air filters is not all that hard for most Alliance homeowners, but there are often two challenges to actually getting it done:
  1. Determining just how often to change your furnace or air conditioner filter.
  2. Replacing them at the proper time.

When To Change Your Air Filters

Most filters have a printed "expiration" date on the wrapping. It may read "Lasts up to 3 months" or "Change filter every 90 days". Pay attention at the store and you'll see that some are designed to only last a month, while other manufacturers (like Honeywell) have created media air cleaners with filters meant to be swapped once every 6-12 months. The standard seems to be once every 3 months for most higher quality filters, but we have a rule of thumb that we recommend our readers to go by. If the filter is dirty, change it! A dirty air filter can contribute or cause damage to expensive equipment, like your compressor, so it's best to change it out more often than neglect it. If you want to listen to the manufacturer's recommended limit, we suggest marking the date on the filter when you swap it out, and programming a reminder for yourself in your phone or on a calendar. Also note that your filter manufacturer might have a different recommendation from your HVAC unit manufacturer.

Figuring out how often to change your air filters hinges on several factors:

  • Type of filter your A/C system requires
  • The collective air quality of your Alliance area home
  • Pets – Birds, cats, dogs, hamsters (do you have one?), etc.
  • Number of people in the home
  • How much construction is taking place in the neighborhood around your home

For your typical 1"-3" air filters, the manufacturer specs basically tell you to change them bi-monthly, which is in fact a great rule of thumb. However, generalities may not be suitable for your specific needs. If you put up with light to moderate allergies, you might require an upgraded air filter or change them even more regularly than OEM specifications. On the other hand, if you're in a less populated area, own a seldom occupied home (like a vacation home) or an area where there are fewer cars around, replacing your air filters each year may be quite sufficient. Why should you factor in your pets? They have a tendency to shed, which can clog your air filter fast. Naturally, the air filter is just doing its job by containing pet hair and dander, but extremely dirty filters can cause seriously reduced HVAC performance.

In summary:

  • Seldom used home or single occupant homes without pets or allergies: Change 6-12 months
  • Average suburban home without pets: Change every 90 days
  • Got a cat or dog: Change every 60 days
  • More than one pet or have allergies: Change every 30-45 days

How To Remember To Change Your Air Conditioner's Air Filters

It's simple; sign up for the Service Experts Email Club. This is a great to receive discounts on service, tips and other helpful information directly to your email. But wait… there’s more, your email subscription preferences let’s you set a reminder to change your Alliance area home's air filter every 30, 60, 90, 120 or 365 days, or a specific date of your choice.

How to replace your return air filter

Most of you know how to replace the air filter in their unit, but some homes have an extra filter in the return ductwork. Whether you have one or not is dependent on what your unit's manufacturer recommends. Your HVAC is engineered to handle a set amount of pressure in your home sweet home, and the more filters you have the harder the blower motor works, which can shorten the lifespan of your system if it isn't designed for it. Discovering whether you have a return filter and replacing it is simple:

  1. Locate your return air vents.
  2. Some covers have screws and some have tabs. Unscrew or pull tabs to pull off the wall.
  3. Check for a filter. If one is there, pull it out and write down the size.
  4. Verify the filter type is the one recommended by the manufacturer.
  5. If filter is dirty, replace with the manufacturer's recommended filter of the same size and type.
Amazing as it may seem, filters can greatly affect your home's airflow, which is why we recommend checking in with the manufacturer. A more expensive HEPA filter that is designed to catch tinier debris will obstruct airflow more than a cheaper filter. With restricted airflow comes greater pressure on your system, so you should verify that your HVAC system was built to handle it. Otherwise, you could experience uneven heating and cooling efficiency in your home, and unit parts may wear out much faster than normal.