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

Every once in a while we’re asked what is the most important thing that the U.S. area homeowner’s can do to ensure efficient functionality of their air conditioning and heating system between their scheduled tune-ups? The answer is simple this; remember to change the heating and air conditioning air filter. Changing furnace and return air filters is critical to the proper performance of your HVAC system, in addition to your home’s air quality. Studies show that 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 difficult for most the U.S. homeowners, but there are usually two challenges to actually getting it done: 

  1. Determining just how often to change your furnace or air conditioner filter. 
  1. Remembering to change air filters when needed. 

When To Change Your Air Filters 

Most filters have a recommended guideline on the wrapping. It may say “Lasts up to 3 months” or “Change filter every 90 days”. Check out the filters at the store and you’ll notice that some are meant to only last a month, while other manufacturers (like Honeywell) have produced media air cleaners with filters meant to be changed once every 6-12 months. The norm seems to be once every few 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 exacerbate or cause damage to expensive parts, 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 be aware that your filter manufacturer sometimes has a different recommendation from your HVAC system manufacturer. 
 
Choosing how often to change your air filters relies upon several factors: 

  • Which air filter your system requires 
  • The overall air quality of your the U.S. area home 
  • Pets – Dogs, cats, etc. 
  • Occupancy of the home 
  • General air pollution in the the U.S. area or construction taking place nearby 

For the common 1″-3″ air filters, the manufacturer specs basically suggest 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 need to upgrade your air filter or change them even more frequently than OEM specifications. On the other hand, if you’re in a less populated area, own a less occupied home (like a vacation home) or an area where there are fewer cars around, annual replacement of your air filter may be quite sufficient. Why do pets matter so much? 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 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 
  • Typical suburban home without pets: Change every 90 days 
  • Add a dog or cat: 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 

Here’s an easy way to stay on top of this; 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. In addition, your email subscription preferences let’s you set a reminder to change your the U.S. 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 of you know how to replace the air filter in their equipment, but some homes have another filter in the return ductwork. Whether you have one or not is dependent on what your unit’s manufacturer recommends. Your HVAC is designed to handle a certain amount of pressure in your house, and the more filters you have the more the blower motor works, which can reduce the lifespan of your system if it isn’t designed for it. Learning whether you have a return filter and replacing it is easy: 

  • Find your return air vents. 
  • Some covers have screws and some have tabs. Unscrew or pull tabs to take off the wall. 
  • Check for a filter. If one is there, pull it out and note the size. 
  • Verify the filter type is the one recommended by the manufacturer. 
  • If the filter is dirty, replace with the manufacturer’s recommended filter of the same size and type. 

Incredible though it may seem, filters can really affect your home’s airflow, which is why we recommend asking the manufacturer. A higher quality HEPA filter that is designed to catch smaller particles will restrict airflow more than a cheaper filter. With restricted airflow comes greater pressure on your system, so you need to verify that your HVAC system was made to handle it. Otherwise, you might experience uneven heating and cooling efficiency in your home, and system parts may wear out much faster than the standard. 

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