Should I Select “On” or “Auto” Fan Setting on My Thermostat?

Most basic thermostats have two fan settings: “auto” or “on.”

The “on” setting tells your Georgia air-conditioner or furnace to run its fans uninterrupted. With the “auto” setting, your fans only spin during cycles when the system is heating or cooling your air.

You may find it helpful to try out each setting and see which one better suits your needs. Each has its pros and cons. For the most convenient and efficient experience, the US Environmental Protection Agency (EPA) recommends switching to a programmable thermostat. Its automated cycling can save you up to 10 percent yearly on utilities without sacrificing comfort.

Carter & Sons HVAC is proud to provide years of expertise and heating, ventilation, and air conditioning (HVAC) service to Carter & Sons HVAC homeowners. Straight from our headquarters, here’s what you need to know about the “on” and “auto” settings:

Setting Your Thermostat to “On”

The Pros

The “on” setting can work wonders for indoor air quality (IAQ). Constant airflow lets the filter catch higher concentrations of dust and debris. Additionally, it will create a dryer environment, making it tougher for mold to grow. If you or a loved one has respiratory issues like allergies or asthma, this may be the setting for you. Also, less frequent starts and stops for your fan may lengthen its lifespan.

The Cons

Since your air filter is catching more particles, you may need to clean or replace it more frequently. This setting also uses more energy, which means your utility bill may be a bit higher than when you set it to “auto.” Additionally, having the fan on all the time during the winter might feel cold.

Setting Your Thermostat To “Auto”

The Pros

Think of “auto” as the efficiency setting. Many homeowners favor it because it uses less energy. When your fan spends less time running, you will consume less power. The heat setting will also feel warmer since less air gets pushed around.

The Cons

The intermittent “start-and-stop” mechanism means your HVAC equipment gets heavier use. This may contribute to a shorter lifespan, on average. Less circulation may not feel as refreshing on a hot day. You’ll also lose some of the IAQ benefits that come from a more robust airflow.

Our recommendations

Many homeowners achieve the best results by combining the two settings. For instance, you can set it to “on” for ventilation during the day, then “auto” at night. You can also switch up the settings as seasons change.

Another way to get the best of both worlds is by upgrading to a smart thermostat, which uses feedback from your living habits to give you the perfect automated setting. You can control it remotely from your smartphone and get weekly energy usage reports.

Call Your Hometown HVAC Team Today

Carter & Sons HVAC is pleased to keep our customers informed about the many ways to get the most out of your HVAC system. Do you have more questions? Need heating and cooling service? Call our Marietta, Georgia, office at 770-434-4095, or request service online today.