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Should I Set My Cincinnati HVAC Fan to Auto or On?

Thermostat Fan Control | Nelson Comfort

The fan in your Cincinnati heating and cooling system operates whenever your furnace or air conditioner are running. When the heating and cooling systems end their cycle, you have the choice to either keep the fan running, or it can cease when your HVAC systems do. Fan use can impact your comfort and energy consumption.

On your thermostat, you’ll find the option to set the fan to either ‘auto’ or ‘on’…. What is the difference between these settings?

Setting your HVAC fan to ‘auto’

When the auto setting is selected, the fan will only run when the heating or cooling system is in operation; the fan works to push conditioned air through the duct system and into your living spaces. It’ll shut off when your furnace or air conditioner does.

Using the auto setting has some advantages:

  • Lower energy use, as the fan isn’t constantly running
  • Less wear and tear on fan components
  • Longer furnace filter life

The disadvantage to using the auto setting is that indoor air can feel stagnant when the fan isn’t running. Air circulation is limited when the fan isn’t running; if your windows aren’t open for natural ventilation, you may notice some stuffiness between heating or cooling cycles.

Setting your HVAC fan to ‘on’

When your HVAC fan is set to on, it will operate 24/7, even after heating or cooling cycles have ceased. The fan will constantly circulate air through your home or commercial building.

The advantages of using the on setting include:

  • Air seems fresher
  • Odor control

Because your fan is constantly running, your energy bills will be higher. With constant air circulation, you will need to change your furnace filter more frequently. Your fan components will require more maintenance and are likely to wear out early.

If you need assistance with the HVAC system fan in your Cincinnati home or business, Nelson Comfort will be happy to assist you. Contact us today to schedule an appointment.

About The Author


Dan Detmer

Dan Detmer is the owner of Nelson Comfort. Dan was born into the heating and cooling industry, coming from a family of well respected HVAC contractors in Dayton, Ohio. After working in the family business, Dan decided to work for a local HVAC wholesale business helping local contractors grow their business. When he felt his heart moving him back into the residential and light commercial business, Dan joined the Mortimer Heating & Cooling team in Cincinnati, where he had called home and become part of the community for several years. After a short period of time Dan purchased the company and created what is today, Nelson Comfort. Today he operates a company based on integrity, honesty, and stellar customer service. If you have any questions feel free to tweet (at sign) NelsonComfort and we will get right back with you!

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