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

February 26, 2015

Sometimes we’re asked what is the most important thing that Kitchener area homeowner's can do to secure their air conditioning and heating system between their scheduled tune-ups? Our advice is simple; remember to change the heating and air conditioning air filter. Replacing furnace and return air filters is critical to the effectiveness of your HVAC system, as well as your home's air quality. Did you know indoor air pollution is among the top five environmental health risks? We know it's the last thing on your mind, but this is really important stuff. Changing the air filters is not difficult for most Kitchener homeowners, but there are typically two obstacles to actually completing this job:

  1. Knowing just how often to swap out your furnace or air conditioner filter.
  2. Remembering to change air filters when needed.

When To Change Your Air Filters

Most filters have a printed "expiration" date on the box or plastic. 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 one month, while other manufacturers (like Honeywell) have released media air cleaners with filters meant to be swapped once every 6-12 months. The norm seems to be once every 3 months for most higher quality filters, but we have a rule of thumb that we tell our friends and family to go by. If it's dirty, change it! A dirty air filter can contribute or cause damage to costly equipment, like your compressor, so it's recommended to change it out more often than neglect it. If you want to listen 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. Keep in mind that your filter manufacturer sometimes has a different recommendation from your HVAC unit manufacturer.

Determining how often to change your air filters can depend on several factors:

  • The type of air filter you are using
  • The overall air quality of your Kitchener area home
  • Pets – Cats, dogs, birds, etc.
  • Number of people in the home
  • General air pollution in the Kitchener area or construction taking place nearby

For your typical 1"-3" air filters, the manufacturer specs basically suggest to change them bi-monthly, which is in fact a great rule of thumb. However, general guidelines are not applicable to all. If you put up with light to moderate allergies, you might need to upgrade your air filter or change them even more often 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 little auto traffic, 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 in no time, just like a vacuum. Clearly, the air filter is just doing its job by trapping pet hair and dander, but extremely dirty filters can cause weak HVAC performance.

In summary:

  • Infrequently occupied home or single occupant homes without pets or allergies: Change 6-12 months
  • Common suburban home without pets: Change every 90 days
  • House with a pet: 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. Plus, your email subscription preferences let’s you set a reminder to change your Kitchener area home's air filter every 30, 60, 90, 120 or 365 days, or any date you find most convenient.

How to replace your return air filter

Most people know how to replace the air filter in their equipment, but some residences have an extra filter in the return ducts. Whether you have one or not is dependent on which HVAC system you have. Your HVAC is designed to handle a maximum amount of pressure in your home sweet 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. Learning whether you have a return filter and replacing it is easy:

  1. Go to your return air vents.
  2. Some covers have screws and some have tabs. Unscrew or pull tabs to remove from the wall.
  3. Inspect 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.
Crazy as it may seem, filters can really alter your home's airflow, which is why we recommend asking the manufacturer. A more expensive HEPA filter that is designed to catch smaller debris will restrict airflow more than a cheaper filter. With restricted airflow comes more pressure on your system, so you need to verify that your HVAC system was built to handle it. Otherwise, you could experience reduced heating and cooling efficiency in your home, and unit parts may wear out much faster than the standard.
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