Once the weather begins to cool off, you may be concerned about how you’ll take full advantage of your heating and cooling. After all, HVAC bills frequently add up to a large piece of your monthly electric bill. To learn new ways to lower their HVAC bill, some owners look closely at their thermostat. Could there be a setting they should use to boost efficiency?
Most thermostats come with a ‘Fan’ or ‘Fan On’ setting. But if the fan is running during a typical cycle, what will the fan setting provide for an HVAC system? This guide should help. We’ll share just what the fan setting is and when you can use it to reduce costs during the summer or winter.
What Is the Fan Setting on My Thermostat?
For most thermostats, the fan setting indicates that the system's blower fan keeps running. Certain furnaces may continue to generate heat at a low level with this setting, but in most cases heating or cooling isn’t being made. The ‘Auto’ setting, on the other hand, will start the fan over a heating or cooling cycle and switch it off after the cycle is complete.
There are advantages and disadvantages to switching on the fan setting on your thermostat, and whether you do or don’t will depend on your distinct comfort requirements.
Advantages to using the Fan/On setting:
- You can keep the temperature in every room more balanced by allowing the fan to keep running.
- Indoor air quality will be highest since steady airflow will keep moving airborne pollutants into the air filter.
- A smaller amount of start-stop cycles for the blower fan helps extend its life span. Since the air handler is typically a component of the furnace, this means you could avoid needing furnace repair.
Drawbacks to switching to the Fan/On setting:
- A nonstop fan could increase your energy bills somewhat.
- Nonstop airflow can clog your air filter soon, increasing the frequency you’ll need to replace it.
Should My Thermostat Be on Fan or Auto in Summer/Winter
Through the summer, warm air will sometimes linger in unfinished spaces like the attic or an attached garage. If you keep the fan running, your HVAC system might gradually move this warm air into the rest of your home, forcing the HVAC system to run longer to keep up with the desired temperature. In severe heat, this could result in needing AC repair more often as wear and tear grows.
The reverse can happen in the winter. Cooler spaces such as a basement will hold onto cooler air, which can eventually drift into the rest of your home. Leaving the fan setting on will sometimes draw more cold air upward, increasing the amount of heating you need to remain warm.
If you’re still trying to decide if you should switch to the fan/on setting, keep in mind that every home and family’s comfort needs will vary. Leaving the HVAC system’s fan on might be best for you if:
Someone in your household deals with allergies. Allergies and similar respiratory conditions can be stressful on the family. Leaving the fan on can help to increase indoor air quality, helping your family breathe easier.
Your home experiences hot and cold spots. Many homes wrestle with stubborn hot and cold spots that quickly shift to a temperature different from the rest of the house. The fan setting might help lessen these changes by constantly refreshing each room’s ventilation.