As the weather begins to cool off, you may be thinking about how you’ll take full advantage of your heating and cooling. After all, HVAC bills frequently contribute a significant portion of your monthly electric bill. To figure out new ways to reduce costs, some owners look closer at their thermostat. Is there a setting they should use to boost efficiency?
Most thermostats have a ‘Fan’ or ‘Fan On’ setting. But if the fan is going during a typical cycle, what will the fan setting provide for the HVAC system? This guide will help. We’ll share precisely what the fan setting is and when you can use it to save money in the summer or winter.
What Is the Fan Setting on My Thermostat?
For most thermostats, the fan setting indicates that the HVAC blower fan keeps running. A few furnaces can run at a low level in 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 switch it off once the cycle is over.
There are pros and cons to using the fan setting on your thermostat, and what's ideal should 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 running.
- Indoor air quality should improve as steady airflow will keep passing airborne particles through the air filter.
- Fewer start-stop cycles for the system's fan helps expand its life span. Since the air handler is often a component of the furnace, this means you could prevent the need for furnace repair.
Downsides to using the Fan/On setting:
- A constant fan could increase your energy expenses slightly.
- Nonstop airflow could clog your air filter in a shorter amount of time, increasing the frequency you should replace it.
Should My Thermostat Be on Fan or Auto in Summer/Winter
Through the summer, warm air will sometimes persist in unfinished spaces including the attic or an attached garage. If you leave the fan on, your HVAC system may pull this warm air into the rest of your home, forcing the HVAC system to work harder to maintain the preferred temperature. In extreme heat, this could result in needing AC repair more quickly as wear and tear gets worse.
The opposite can happen in 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. Keeping the fan on may pull more cold air upward, increasing the amount of heating you need to stay warm.
If you’re still trying to decide if you should try the fan/on setting, don’t forget that every home and family’s comfort needs will vary. Leaving the HVAC system’s fan on could be best for you if:
Someone in your household has allergies. Allergies and similar respiratory conditions can be hard on the family. Leaving the fan on can help to enhance indoor air quality, helping your family breathe easier.
Your home has hot and cold spots. Many homes deal with difficult hot and cold spots that quickly return to a temperature different from the rest of the house. The fan setting might help minimize these changes by constantly refreshing each room’s supply of air.