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

Occassionally we’re asked what is the most important thing that the U.S. area homeowner’s can do to secure their air conditioning and heating system between their scheduled 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, not to mention your home’s air quality. Did you know indoor air pollution is one of 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 all that hard for most the U.S. homeowners, but there are often two challenges to actually accomplishing this task: 

1. Understanding 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 timeline printed on the packaging. It may read “Lasts up to 3 months” or “Change filter every 90 days”. Pay attention at the store and you’ll notice that some are meant to only last one month, while other manufacturers (like Honeywell) have created media air cleaners with filters meant to be changed 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 tell our customers to go by. If they’re dirty, change them! A dirty air filter can contribute or cause damage to expensive components, like your compressor, so it’s better to change it out more often than neglect it. 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. Keep in mind that your filter manufacturer may have a different recommendation from your HVAC system manufacturer. 
 
Figuring out how often to change your air filters can depend on several factors: 

• The type of air filter you are using 
• The entire air quality of your the U.S. area home 
• Pets – Dogs, cats, etc. 
• Occupancy of the home 

• The level of air pollution and construction around the home 

For the common 1″-3″ air filters, the OEM specs basically tell you to change them every 30-60 days, which is in fact a great rule of thumb. However, general rules aren’t always for everybody. If you suffer from light to moderate allergies, you may need to upgrade the 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 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 fast. Obviously, 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 
• Typical suburban home without pets: Change every 90 days 

• Add a dog or cat: Change every 60 days 
• Multiple 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. When you do, you can elect to receive (or not) great email coupons and newsletters with a lot of tips and discounts on AC repairs and tune-ups. 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 people know how to replace the air filter in their unit, but some homes have an additional filter in the return ductwork. Whether you have one or not is dependent on what your unit’s manufacturer recommends. Your system is designed to handle a maximum amount of pressure in your home, and the more filters you have the harder the blower motor works, which can shorten the life expectancy of your system if it isn’t designed for it. Discovering whether you have a return filter and replacing it is easy: 

• Locate your return air vents. 

• Some covers have screws and some have tabs. Unscrew or pull tabs to pull off the wall. 

• Check for a filter. If one is inside, 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. 

Amazing as it may seem, filters can dramatically affect your home’s airflow, which is why we recommend checking in with the manufacturer. A higher quality HEPA filter that is designed to catch finer 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 built to handle it. Otherwise, you may experience reduced heating and cooling efficiency in your home, and system parts may wear out much faster than normal.