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Choosing the Right Setting for Your Air Conditioning and Furnace Fan

Your furnace and air conditioning system does more than just control the temperature in your home. The system also uses a fan to circulate the air around your house, so you can enjoy a comfortable environment no matter where you are inside. However, there are usually several fan settings, which can be confusing to homeowners who aren't familiar with how their furnace and air conditioning system works. Read on for advice on how to set up your HVAC fan for maximum comfort and efficiency.

Are You an "Auto" or an "On" Family?

Most furnace and air conditioning systems have two fan settings: "On" and "Auto." The labels may not be particularly clear to the layperson, but there is a distinction:

  • On means that the fan is constantly running, pushing air through the house whether the AC or furnace is active or not.
  • Auto, on the other hand, only moves the air when the HVAC unit is actually in its heating or cooling cycle.

Still confused? There are plenty of good reasons to use either setting, depending on your personal preferences.

Automatic for the People

One major benefit of using the automatic fan setting is that you save energy by shutting it down when the AC and furnace aren't doing their thing. This also means that your fan motor will last longer before you need to service it, since it's not running all the time. On the flip side, allowing the fan to switch off means that the air can grow stagnant in between heating and cooling cycles, and you won't get as much filtering action, allowing pollen and dust to linger around longer.

Turn On, Tune In, Drop Out

An always-on fan setting shines in areas where the automatic function falls short. If the fan is blowing all the time, the air in your home is constantly being filtered and replaced, so your indoor air quality should remain top-notch. This can be a lifesaver for people who suffer from asthma or other respiratory ailments. Of course, this does mean you have to be more diligent about changing the filter in your furnace and air conditioning system, or it will become clogged and bring down its overall efficiency. Furthermore, your electricity bills will be higher and you will probably have to service or replace the fan motor more frequently. Finally, using the fan when the air conditioner isn't cooling can draw humid air back into the house in the summer, which can counteract some of the comfort you gain from the continuous air distribution.

The Choice is Yours

Overall, it's up to you to decide if you prefer saving money on your electric bills or keeping your ventilation system running all the time. You can also investigate options like a variable speed blower or hooking your HVAC system into a smart thermostat that can give you more fan options than just "On" or "Auto." If you need more help deciding what to do or getting your fan set up properly, have an air conditioning and heating technician come lend a hand.