As the weather is cooling off, you might be thinking about how you’ll prepare your heating and cooling. After all, HVAC costs routinely make up a big piece of your monthly electric bill. To try and find ways to reduce costs, some homeowners look closely at their thermostat. Is there a setting they should use to boost efficiency?
The majority of 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 will help. We’ll share just what the fan setting is and whether you can use it to reduce costs over the summer or winter.
What Is the Fan Setting on My Thermostat?
For the bulk of thermostats, the fan setting indicates that the HVAC blower fan remains on. Certain furnaces can run at a low level in this setting, but for the most part heating or cooling isn’t being generated. The ‘Auto’ setting, in contrast, will run the fan through a heating or cooling cycle and turn it off after the cycle is finished.
There are advantages and disadvantages to trying the fan setting on your thermostat, and what's ideal can depend on your distinct comfort requirements.
Advantages to switching to the Fan/On setting:
- You can keep the temperature in each room more balanced by enabling the fan to keep circulating air.
- Indoor air quality should improve as constant airflow will keep passing airborne particles through the air filter.
- A smaller number of start-stop cycles for the HVAC fan helps lengthen its life span. As the air handler is often a component of the furnace, this means you could minimize the risk of needing furnace repair.
Downsides to using the Fan/On setting:
- A continuous fan will likely raise your energy bills slightly.
- Constant airflow may clog your air filter up more quickly, increasing the frequency you should replace it.
Should My Thermostat Be on Fan or Auto in Summer/Winter
During the summer, warm air will sometimes stick around in unfinished spaces such as the attic or an attached garage. If you use the fan setting, your HVAC system may draw this warm air into the rest of your home, pushing the HVAC system to work harder to maintain the preferred temperature. In severe heat, this may lead to needing AC repair more often as wear and tear grows.
The opposite can occur during 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 may pump more cold air upward, increasing the amount of heating you need to stay warm.
If you’re still trying to figure out if you should try the fan/on setting, remember that every home and family’s comfort needs are different. Leaving the HVAC system’s fan on could be best for you if:
Someone in your household deals with allergies. Allergies and similar respiratory conditions can be tough on the family. Leaving the fan on can help to improve indoor air quality, helping your family breathe easier.
Your home has hot and cold spots. Lots of homes wrestle with stubborn hot and cold spots that quickly evolve to a temperature different from the rest of the house. The fan setting should help minimize these changes by consistently refreshing each room’s ventilation.