Once the weather begins to cool off, you might be wondering about how you’ll take full advantage of your heating and cooling. After all, HVAC expenses frequently contribute a big portion of your monthly electric bill. To learn new ways to reduce costs, some owners take a closer look at their thermostat. Maybe there’s a setting they could use to increase efficiency?
Most thermostats have a ‘Fan’ or ‘Fan On’ setting. But if the fan is running during a typical cycle, what does the fan setting provide for your HVAC system? This guide can help. We’ll review just what the fan setting is and whether you can use it to reduce costs in the summer or winter.
What Is the Fan Setting on My Thermostat?
For the bulk of thermostats, the fan setting means that the HVAC blower fan stays on. A few furnaces will run at a low level in this setting, but in general heating or cooling isn’t being produced. The ‘Auto’ setting, on the other hand, will turn on the fan over a heating or cooling cycle and shut it off once the cycle is over.
There are benefits and drawbacks to switching on the fan setting on your thermostat, and what's ideal will depend on your distinct comfort needs.
Advantages to utilizing the Fan/On setting:
- You can keep the temperature in every room more uniform by enabling the fan to keep running.
- Indoor air quality will be highest since constant airflow will keep forcing airborne pollutants into the air filter.
- A smaller amount of start-stop cycles for the HVAC fan helps expand its life span. Since the air handler is usually part of the furnace, this means you can prevent the need for furnace repair.
Disadvantages to switching to the Fan/On setting:
- A nonstop fan will likely increase your energy costs by a small margin.
- Constant airflow may clog your air filter up more quickly, increasing the frequency you will want to replace it.
Should My Thermostat Be on Fan or Auto in Summer/Winter
Through the summer, warm air may linger in unfinished spaces like the attic or an attached garage. If you keep the fan running, your HVAC system can pull this warm air into the rest of your home, compelling the HVAC system to work harder to preserve the preferred temperature. In extreme heat, this could lead to needing AC repair more regularly as wear and tear gets worse.
The opposite can occur during the winter. Cooler spaces such as a basement will hold onto cooler air, which may eventually flow into the rest of your home. Keeping the fan on will sometimes draw more cold air upward, increasing the amount of heating you need to remain warm.
If you’re still trying to figure out if you should try the fan/on setting, don’t forget that every home and family’s comfort needs are different. Leaving the HVAC system’s fan on may be ideal for you if:
Someone in your household suffers from allergies. Allergies and other respiratory conditions can be stressful on the family. Leaving the fan on is more likely to increase indoor air quality, helping your family breathe easier.
Your home deals with hot and cold spots. Many homes wrestle with persistent 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 consistently refreshing each room’s airflow.