As the weather starts to cool off, you may be concerned about how you’ll make the most of your heating and cooling. After all, HVAC expenses routinely make up a large chunk 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 can use to boost efficiency?
The majority of thermostats have a ‘Fan’ or ‘Fan On’ setting. But if the fan is going during a regular cycle, what does the fan setting provide for the HVAC system? This guide should help. We’ll review precisely what the fan setting is and whether you can use it to cut costs in the summer or winter.
What Is the Fan Setting on My Thermostat?
For the majority of thermostats, the fan setting signifies that the air handler’s blower fan stays on. A few furnaces can generate heat at a low level in this setting, but in general heating or cooling isn’t being produced. The ‘Auto’ setting, in contrast, will start the fan during a heating or cooling cycle and switch it off when the cycle is over.
There are pros and cons to trying the fan setting on your thermostat, and what's ideal can depend on your unique comfort requirements.
Advantages to switching to the Fan/On setting:
- You can keep the temperature in each room more consistent by enabling the fan to keep circulating air.
- Indoor air quality can increase since steady airflow will keep forcing airborne particles through the air filter.
- A smaller number of start-stop cycles for the HVAC fan helps lengthen its life span. Since the air handler is typically part of the furnace, this means you could prevent the need for furnace repair.
Drawbacks to using the Fan/On setting:
- A constant fan can add to your energy bills slightly.
- Constant airflow could 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 may linger in unfinished spaces such as the attic or an attached garage. If you keep the fan running, your HVAC system might draw this warm air into the rest of your home, forcing the HVAC system to work more to preserve the set temperature. In severe heat, this may lead to needing AC repair more often as wear and tear gets worse.
The opposite can happen over the winter. Cooler spaces such as a basement will hold onto cooler air, which will eventually make its way into the rest of your home. Leaving the fan setting on could draw more cold air upward, increasing the amount of heating you need to keep warm.
If you’re still trying to decide if you should use 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 is more likely to improve indoor air quality, helping your family breathe easier.
Your home deals with hot and cold spots. All kinds of homes deal with persistent hot and cold spots that quickly return to a temperature different from the rest of the house. The fan setting might help limit these changes by steadily refreshing each room’s airflow.