As the weather begins to cool off, you are probably wondering about how you’ll prepare your heating and cooling. After all, HVAC costs routinely make up a big chunk of your monthly electric bill. To try and find ways to lower their HVAC bill, some owners take a closer look at their thermostat. Maybe there’s a setting they should use to improve efficiency?
Most thermostats include both a ‘Fan’ or ‘Fan On’ setting. But if the fan is going during a typical cycle, what does the fan setting offer for an HVAC system? This guide should help. We’ll review what exactly the fan setting is and whether you can use it to cut costs over the summer or winter.
What Is the Fan Setting on My Thermostat?
For most thermostats, the fan setting indicates that the air handler’s blower fan remains on. A few furnaces will run at a low level with this setting, but in most cases heating or cooling isn’t being produced. The ‘Auto’ setting, conversely, will turn on the fan through a heating or cooling cycle and turn it off once the cycle is over.
There are benefits and drawbacks to trying the fan setting on your thermostat, and whether you do or don’t will depend on your unique comfort preferences.
Advantages to using the Fan/On setting:
- You can keep the temperature throughout your home more consistent by enabling the fan to keep circulating air.
- Indoor air quality should improve since steady airflow will keep forcing airborne pollutants into the air filter.
- Fewer start-stop cycles for the HVAC fan helps extend its life span. Because the air handler is usually connected to the furnace, this means you could minimize the risk of needing furnace repair.
Downsides to using the Fan/On setting:
- A continuous fan could raise your energy bills somewhat.
- Nonstop 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
In the summer, warm air may stick around in unfinished spaces including 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, compelling the HVAC system to work more to maintain the set temperature. In severe heat, this may result in needing AC repair more quickly as wear and tear grows.
The opposite can occur during the winter. Cooler spaces like a basement will hold onto cooler air, which may eventually make its way into the rest of your home. Keeping the fan on will sometimes pull more cold air upward, increasing the amount of heating you need to stay warm.
If you’re still trying to determine if you should use the fan/on setting, remember that every home and family’s comfort needs are not the same. Leaving the HVAC system’s fan on might be best for you if:
Someone in your household has allergies. Allergies and similar respiratory conditions can be stressful on the family. Leaving the fan on should help to enhance indoor air quality, helping your family breathe easier.
Your home has hot and cold spots. Lots of homes deal with persistent hot and cold spots that quickly evolve 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.