When Should I Change My Furnace's Air Filter?

February 26, 2015

Sometimes we’re asked what is the most important thing that Birmingham area homeowner's can do to maintain their air conditioning and heating system between their scheduled PLUS Maintenance Tune-ups? The answer is simple this; remember to change the heating and air conditioning air filter. Buying new furnace and return air filters is critical to the proper performance of your HVAC system, plus 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 Birmingham homeowners, but there are typically two challenges to actually getting it done:

  1. Determining just how often to change 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 packaging. It may instruct "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 one 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 suggest our readers to go by. If it's dirty, change it! A dirty air filter can contribute or cause damage to pricey parts, like your compressor, so it's better to change it out more often than not. If you want to follow the manufacturer's recommended limit, we suggest marking the date on the filter when you swap it out, and adding 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.

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

  • Which air filter your system requires
  • The collective air quality of your Birmingham area home
  • Pets – Birds, cats, dogs, hamsters (do you have one?), etc.
  • Number of occupants in the house
  • How much construction is taking place in the neighborhood around your home

For the common 1"-3" air filters, the OEM specs basically tell you to change them bi-monthly, which is really a great rule of thumb. But generalities may not be suitable for your specific needs. If you suffer from 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 seldom occupied home (like a vacation home) or an area with little auto traffic, replacing your air filters each year may be quite sufficient. Why do we call out our beloved pets? They have a tendency to shed, which can clog your air filter quick. Obviously, the air filter is just doing its job by trapping 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
  • Common 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 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. Plus, your email subscription preferences let’s you set a reminder to change your Birmingham 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 of us know how to replace the air filter in their equipment, but some houses 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 maximum amount of pressure in your home sweet home, and the more filters you have the harder the blower motor works, which can reduce the life expectancy of your system if it isn't designed for it. Learning whether you have a return filter and replacing it is simple:

  1. Go to 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 in place, 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.
Incredible though it may seem, filters can really impact your home's airflow, which is why we recommend referring to the manufacturer. A more expensive HEPA filter that is designed to catch smaller debris will reduce 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 might experience uneven heating and cooling efficiency in your home, and unit parts may die off much faster than normal.

 

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