While winter months in Arizona are significantly cooler than the summer months, they can still be quite warm. The question is, can you just run the fan on your thermostat to keep your home at a comfortable temperature? We are going to dive deeper into what it means to have your fan “ON”, the pros and cons of running just the fan, and what it means for your air quality.

Most HVAC systems offer two options when it comes to your fan: “AUTO” vs. “ON”.

  • “AUTO” mode means the fan will run only if there is a call for heating or cooling. 
  •  “ON” mode means the indoor fan will run nonstop until you switch the settings. This setting also continuously circulates and filters the air in your home.


Running the fan only during the winter months may keep your home comfortable, but it also comes with a few setbacks. Turning the fan to “ON” is going to continuously blow filtered air through your home. If you have sensitive allergies or respiratory conditions, this may be a good option for you as you will always have “fresh” air in your home. 

While running switching the fan setting to “ON” has great advantages, it also comes with a few drawbacks. You will likely see a change in your utility bills and you will want to be diligent about scheduling your routine maintenance. With the continuous flow of air, your filter will need to be replaced more frequently as well.


With your fan set to the “AUTO” setting, you will cut back on your energy consumption. This will likely reduce your utility bills and the amount you are running your HVAC system. While your system is not running continuously, you will be able to extend the time between the recommended preventative maintenance. 

The biggest drawback of setting your fan to “AUTO” is the air inside your home could become idle. This means the air within your home can become permeated with dust, pollen, pet dander, and other air ridden irritants. If you are not prone to allergies, this might not be as much of a concern as saving a little bit on your utilities.

So which is the best option for an Arizona home? That is only a question you can answer. Taking into account your budget and health conditions, you can decide which is best for you.

If you have further questions about how to increase the quality of air in your home or efficiency of your HVAC system, contact our office today. Call (602) 881-5378 to schedule your free estimate with 2C’s Cooling & Heating. We are available for routine maintenance and repair on all major brand units.

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About 2C’s Cooling & Heating

2C’s Cooling & Heating proudly serves the East Valley, Arizona with high quality HVAC services. We are here to serve you and all of your cooling and heating needs. Our team is prepared to tackle whatever cooling project you have.