Should You Use the Fan On or Auto Option When Setting Your Thermostat?Sometimes it seems that no matter how much you fiddle with the thermostat, you can’t get comfortable in your home. It may be due to elements affecting home comfort other than temperature, such as humidity and indoor air quality. Setting your thermostat correctly for fan options “on” and “auto” can also help or hinder comfort, humidity and indoor air quality, depending on the situation. Use this guide to select the right fan option for your needs.

Using the Fan’s “On” and “Auto” Settings

The “on” option keeps the HVAC system’s fan running even after the cooling or heating cycle has ended. It’s just recycling airflow. The “auto” option turns the fan off when the cooling or heating cycle has ended. Following are the pros and cons of each option in regards to comfort, energy bills and indoor air quality.

Comfort and Humidity

High indoor humidity is a blessing during the dry winter months and a common nuisance during the muggy cooling season. When the fan’s set to “on,” the continuous airflow will evaporate condensation in the A/C and return water vapor and humidity to your home. “Auto” is best for the cooling mode.

During the heating months, the “on” option may actually produce a slight wind chill effect without the heating system running. The “auto” option is generally better for year-round comfort and indoor humidity.

Energy Bills

If you keep an eagle’s eye on energy bills, you’ll want to choose the fan’s “auto” setting. Otherwise, you’re paying more in electricity costs to run the fan around the clock.

Indoor Air Quality

Setting the fan to “on” continuously cycles airflow through the system’s air filter. This helps improve indoor air quality as long as you change or clean the filter regularly. However, you’re paying a high price in electricity consumption for indoor air quality goals that may extend beyond your filter’s capabilities, especially for occupants with respiratory ailments. The better solution for healthy indoor air quality is to use a whole-house air purifier. You can target contaminants you want removed with the right system.

For more tips on setting your thermostat correctly in your Indianapolis home, contact Mowery Heating, Cooling and Plumbing.

Our goal is to help educate our customers in Brownsburg, Indiana and surrounding areas about energy and home comfort issues (specific to HVAC systems).

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