Once the weather begins to cool off, you may be concerned about how you’ll prepare your heating and cooling. After all, HVAC costs can add up to a significant portion of your monthly electric bill. To try and find ways to save, some people look closely at their thermostat. Maybe there’s a setting they can use to boost efficiency?
Most thermostats include both a ‘Fan’ or ‘Fan On’ setting. But if the fan is on during a regular cycle, what will the fan setting provide for the HVAC system? This guide will help. We’ll walk through what exactly the fan setting is and when you can use it to reduce costs during the summer or winter.
What Is the Fan Setting on My Thermostat?
For the bulk of thermostats, the fan setting indicates that the system's blower fan remains on. Certain furnaces can generate heat at a low level in this setting, but in most cases heating or cooling isn’t being made. The ‘Auto’ setting, on the other hand, will turn on the fan during a heating or cooling cycle and turn it off after the cycle is over.
There are pros and cons to switching on the fan setting on your thermostat, and what's ideal can depend on your unique comfort requirements.
Advantages to using the Fan/On setting:
- You can keep the temperature in every room more uniform by permitting the fan to keep generating airflow.
- Indoor air quality should improve because steady airflow will keep passing airborne contaminants into the air filter.
- Fewer start-stop cycles for the HVAC fan helps expand its life span. As the air handler is typically a component of the furnace, this means you could prevent the need for furnace repair.
Downsides to utilizing the Fan/On setting:
- A nonstop fan could add to your energy costs somewhat.
- 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
In the summer, warm air may stick around in unfinished spaces including the attic or an attached garage. If you use the fan setting, your HVAC system can gradually move this warm air into the rest of your home, compelling the HVAC system to run longer to keep up with the preferred temperature. In serious heat, this may result in needing AC repair more regularly as wear and tear grows.
The reverse can occur during the winter. Cooler spaces like a basement will hold onto cooler air, which can eventually flow into the rest of your home. Keeping the fan on could pull more cold air upward, increasing the amount of heating you need to remain warm.
If you’re still trying to figure out if you should switch to the fan/on setting, remember that every home and family’s comfort needs are not the same. Leaving the HVAC system’s fan on may 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 experiences hot and cold spots. Many 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 constantly refreshing each room’s ventilation.