When Should I Change My Furnace's Air Filter?

February 26, 2015

Every once in a while we’re asked what is the number one thing that Roanoke area homeowner's can do to ensure efficient functionality of their air conditioning and heating system between their seasonal 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 crucial to the proper performance of your HVAC system, as well as your home's air quality. Research suggests that indoor air pollution is one of 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 a tough thing to do for most Roanoke homeowners, but there are often two obstacles to actually getting it done:

  1. Understanding 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 timeline printed on the wrapping. It may say "Lasts up to 3 months" or "Change filter every 90 days". Look around at the store and you should see that some are designed to only last a single month, while other manufacturers (like Honeywell) have created media air cleaners with filters meant to be exchanged once every 6-12 months. The norm seems to be once every three 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 pricey equipment, like your compressor, so it's recommended to change it out more often than neglect it. If you want to follow the manufacturer's recommended limit, we suggest writing the date on the filter when you swap it out, and adding a reminder for yourself in your phone or on a calendar. Also note that your filter manufacturer sometimes has a different recommendation from your HVAC equipment manufacturer.

Deciding how often to change your air filters hinges on several factors:

  • Type of filter your A/C system requires
  • The collective air quality of your Roanoke area home
  • Pets – Birds, cats, dogs, hamsters (do you have one?), etc.
  • Number of people in the home
  • The level of air pollution and construction around the home

For your standard 1"-3" air filters, the manufacturers basically suggest to change them bi-monthly, which is in fact a great rule of thumb. Still, general rules aren't always for everybody. If you have to tolerate light to moderate allergies, you may need to upgrade the air filter or change them even more often than OEM specifications. On the other hand, if you're in a low population area, own a seldom occupied home (like a vacation home) or an area with little auto traffic, 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. Naturally, the air filter is just doing its job by capturing pet hair and dander, but exceptionally 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 Air Filters

Here’s an easy way to stay on top of this; 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. In addition, your email subscription preferences let’s you set a reminder to change your Roanoke 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 us know how to replace the air filter in their equipment, but some houses have an extra 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 house, and the more filters you have the fiercer the blower motor works, which can reduce the life 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. 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. Look for a filter. If one is there, pull it out and record 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.
Amazing as it may seem, filters can really alter your home's airflow, which is why we recommend checking in with the manufacturer. A top tier HEPA filter that is designed to catch finer dust will restrict 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 engineered to handle it. Otherwise, you may experience reduced heating and cooling efficiency in your home, and unit parts may wear out much faster than the standard.

 

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