The Eternal Battle: Should You Set Your Fan to "Auto" or "On"? - Biard & Crockett

The Eternal Battle: Should You Set Your Fan to “Auto” or “On”?


You’ve seen the switch on your thermostat, and you’ve probably heard the debates: should you set your thermostat to “auto” or “on”? If you guess wrong, there will be consequences!

Team “on”

The people who say you should have your thermostat set to “on” say so because they say, if you have it set to “auto,” you may already be feeling too hot by the time the fan automatically turns on. They say, setting your fan to run constantly lets cool air distribute better around your home, and that the auto setting doesn’t allow for enough circulation (leading to uneven hot spots and cool spots).

Team “auto”

The people who say you should set your thermostat to auto say, if you have it set to on, you are wasting money and that it’s not necessary to continually be running your A/C in order to keep the temperature where you want it. Also, they argue, when your fan is set to auto, the air conditioner’s cooling coils don’t constantly have humid air being blown over them, which gives the coils a chance to dry off and the moisture a chance to drip into the drip pan. Otherwise, the coils are wetter, which makes your indoor air more humid and forces your A/C system to work harder.

Which side are YOU on?

Personally, here at Biard & Crockett, we are on Team Auto! We’ve heard the argument that the auto setting reduces circulation … but it just doesn’t quite add up. For one thing, the on setting not only puts extra strain on your A/C system (because it never stops working and never gets a break), but also causes air duct leakage, because of the air constantly being forced through them. Leaky ducts is certainly not the way to ensure even distribution of cool air around your home! If you are truly having a problem with hot spots and cold spots in your home, you can set the thermostat to on for immediate relief, but we recommend trying to get to the root cause of the uneven temperature, such as:

  • Blocked-off vents
  • Clogged air filter that needs to be changed
  • Incorrect HVAC system size
  • Improperly placed thermostat (close to a hotter or colder area of your home, throwing off the reading)
  • Leaky ducts (as we just mentioned!)

Call Biard & Crockett

So, as you can see, auto is a better setting for your system and for your wallet, and there should be no reason to run your fan constantly. Whichever of these two settings you’re a “fan” of, you can rely on us to make sure your HVAC system is running as efficiently and flawlessly as possible. Schedule an appointment online or give us a call: (714) 602-1299

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