When the weather is cooling off, you may be thinking about how you’ll make the most of your heating and cooling. After all, HVAC costs routinely add up to a significant chunk of your monthly electric bill. To figure out new ways to lower their HVAC bill, some owners look closely at their thermostat. Is there a setting they can use to improve efficiency?
Most thermostats include both a ‘Fan’ or ‘Fan On’ setting. But if the fan is on during a normal cycle, what will the fan setting offer for the HVAC system? This guide can help. We’ll share just what the fan setting is and when 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 signifies that the HVAC blower fan keeps running. Certain furnaces will run at a low level with this setting, but for the most part heating or cooling isn’t being produced. The ‘Auto’ setting, conversely, will start the fan during a heating or cooling cycle and turn it off after the cycle is complete.
There are benefits and drawbacks to using the fan setting on your thermostat, and whether you do or don’t will depend on your personal comfort needs.
Advantages to switching to the Fan/On setting:
- You can keep the temperature throughout your home more consistent by enabling the fan to keep running.
- Indoor air quality can increase since continuous airflow will keep moving airborne pollutants into the air filter.
- Fewer start-stop cycles for the blower fan helps expand its life span. Because the air handler is often part of the furnace, this means you could avoid needing furnace repair.
Disadvantages to using the Fan/On setting:
- A constant fan could raise your energy costs somewhat.
- Nonstop airflow may clog your air filter in a shorter amount of time, increasing the frequency you’ll need to replace it.
Should My Thermostat Be on Fan or Auto in Summer/Winter
During the summer, warm air can linger in unfinished spaces such as the attic or an attached garage. If you keep the fan running, your HVAC system can gradually move this warm air into the rest of your home, pushing the HVAC system to work more to keep up with the preferred temperature. In extreme heat, this could result in needing AC repair more often as wear and tear gets worse.
The opposite can take place during the winter. Cooler spaces like a basement will hold onto cooler air, which can eventually make its way into the rest of your home. Keeping the fan on may pull more cold air upward, increasing the amount of heating you need to remain warm.
If you’re still trying to determine if you should try the fan/on setting, remember that every home and family’s comfort needs will vary. Leaving the HVAC system’s fan on may be ideal for you if:
Someone in your household has allergies. Allergies and similar respiratory conditions can be hard on the family. Leaving the fan on is more likely to enhance indoor air quality, helping your family breathe easier.
Your home deals with hot and cold spots. All kinds of homes deal with difficult hot and cold spots that quickly return to a temperature different from the rest of the house. The fan setting might help minimize these changes by steadily refreshing each room’s supply of air.