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

February 26, 2015

Sometimes we’re asked what is the number one thing that Louisville area homeowner's can do to ensure efficient functionality of their air conditioning and heating system between their seasonal tune-ups? That’s an easy one; remember to change the heating and air conditioning air filter. Replacing furnace and return air filters is extremely important to the effectiveness of your HVAC system, in addition to your home's air quality. Did you know indoor air pollution is in the top five environmental health risks? It’s not thought of often, but it is extremely important to consider. Changing the air filters is not all that hard for most Louisville homeowners, but there are often two challenges to actually completing this job:

  1. Determining just how often to replace your furnace or air conditioner filter.
  2. Changing them when you’re suppose to.

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 should see that some are engineered to only last a single month, while other manufacturers (like Honeywell) have released media air cleaners with filters meant to be changed once every 6-12 months. The industry standard seems to be once every few months for most higher quality filters, but we have a rule of thumb that we tell our customers to go by. If they're dirty, change them! A dirty air filter can contribute or cause damage to costly parts, like your compressor, so it's better to change it out more often than to let it go. If you want to stick to the manufacturer's recommended limit, we suggest writing the date on the filter when you swap it out, and setting a reminder for yourself in your phone or on a calendar. Also be aware that your filter manufacturer might have a different recommendation from your HVAC system manufacturer.

Figuring out how often to change your air filters relies upon several factors:

  • Type of filter your A/C system requires
  • The collective air quality of your Louisville area home
  • Pets – Birds, cats, dogs, hamsters (do you have one?), etc.
  • Number of occupants in the house
  • General air pollution in the Louisville area or construction taking place nearby

For your typical 1"-3" air filters, the manufacturers basically say to change them every 30-60 days, which is actually a great rule of thumb. But general guidelines are not applicable to all. If you have to endure 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 remote area, own a infrequently occupied home (like a vacation home) or an area with few automobiles and trucks, changing your air filter every 12-months may be quite sufficient. Why should you factor in your pets? They have a tendency to shed, which can clog your air filter quick. Obviously, the air filter is just doing its job by capturing pet hair and dander, but tremendously 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
  • Typical suburban home without pets: Change every 90 days
  • Got a cat or dog: Change every 60 days
  • Several pets 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 convenient way to get money-saving discounts and other helpful information on your smartphone, tablet or desktop. But wait… there’s more, your email subscription preferences let’s you set a reminder to change your Louisville area home's air filter every 30, 60, 90, 120 or 365 days, or the date of your choosing.

How to replace your return air filter

Most people know how to replace the air filter in their unit, but some residences have an extra filter in the return vent. Whether you have one or not is dependent on which HVAC system you have. Your unit is made to handle a maximum amount of pressure in your home, and the more filters you have the more the blower motor works, which can decrease the life expectancy of your system if it isn't designed for it. Finding out whether you have a return filter and replacing it is a piece of cake:

  1. Find your return air vents.
  2. Some covers have screws and some have tabs. Unscrew or pull tabs to take off the wall.
  3. Look for a filter. If one is inside, 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.
Crazy as it may seem, filters can really impact 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 increased pressure on your system, so you need to verify that your HVAC system was built to handle it. Otherwise, you might experience reduced heating and cooling efficiency in your home, and HVAC parts may die off much faster than the standard.
Contact Us