When the weather is cooling off, you are probably concerned about how you’ll make the most of your heating and cooling. After all, HVAC costs frequently contribute a large portion of your monthly electric bill. To try and find ways to lower their HVAC bill, some homeowners look closely at their thermostat. Is there a setting they could use to improve efficiency?
Most thermostats have a ‘Fan’ or ‘Fan On’ setting. But if the fan is going during a normal cycle, what will the fan setting offer for an HVAC system? This guide can help. We’ll walk through precisely what the fan setting is and how 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 means that the air handler’s blower fan stays on. Certain furnaces will run at a low level in this setting, but for the most part heating or cooling isn’t being made. The ‘Auto’ setting, in contrast, will turn on the fan during a heating or cooling cycle and shut it off once the cycle is over.
There are pros and cons to switching on the fan setting on your thermostat, and whether you do or don’t will depend on your unique comfort preferences.
Advantages to utilizing the Fan/On setting:
- You can keep the temperature in every room more balanced by enabling the fan to keep circulating air.
- Indoor air quality will be highest since steady airflow will keep passing airborne particles through the air filter.
- A smaller amount of start-stop cycles for the system's fan helps extend its life span. Because the air handler is typically part of the furnace, this means you might prevent the need for furnace repair.
Downsides to switching to the Fan/On setting:
- A nonstop fan could increase your energy bills by a small margin.
- Continuous 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, forcing the HVAC system to work harder to preserve the desired temperature. In severe heat, this may lead to needing AC repair more often as wear and tear gets worse.
The reverse can occur over the winter. Cooler spaces such as a basement will hold onto cooler air, which can eventually make its way into the rest of your home. Leaving the fan setting on will sometimes pump more cold air upward, increasing the amount of heating you need to stay warm.
If you’re still trying to decide if you should switch to the fan/on setting, remember that every home and family’s comfort needs are different. Leaving the HVAC system’s fan on may work for you if:
Someone in your household has allergies. Allergies and other respiratory conditions can be hard on the family. Leaving the fan on should help to enhance indoor air quality, helping your family breathe easier.
Your home deals with hot and cold spots. Many homes deal with persistent hot and cold spots that quickly shift to a temperature different from the rest of the house. The fan setting should help minimize these changes by constantly refreshing each room’s airflow.