When the weather is cooling off, you are probably concerned about how you’ll prepare your heating and cooling. After all, HVAC bills routinely make up a big piece of your monthly electric bill. To figure out new ways to lower their HVAC bill, some people look closely at their thermostat. Maybe there’s a setting they could use to improve efficiency?
Most thermostats include both a ‘Fan’ or ‘Fan On’ setting. But if the fan is on during a typical cycle, what does the fan setting offer for your HVAC system? This guide can help. We’ll share what exactly the fan setting is and when you can use it to cut costs during the summer or winter.
What Is the Fan Setting on My Thermostat?
For the majority of thermostats, the fan setting means that the air handler’s blower fan remains on. Some furnaces may continue to run at a low level with this setting, but in most cases heating or cooling isn’t being made. The ‘Auto’ setting, on the other hand, will start the fan over a heating or cooling cycle and shut it off after the cycle is finished.
There are pros and cons to using the fan setting on your thermostat, and what's ideal will depend on your distinct comfort needs.
Advantages to trying the Fan/On setting:
- You can keep the temperature throughout your home more balanced by permitting the fan to keep generating airflow.
- Indoor air quality will be highest as constant airflow will keep moving airborne contaminants into the air filter.
- A smaller amount of start-stop cycles for the blower fan helps lengthen its life span. Because the air handler is typically connected to the furnace, this means you can minimize the risk of needing furnace repair.
Drawbacks to switching to the Fan/On setting:
- A continuous fan could add to your energy expenses somewhat.
- Constant airflow could clog your air filter soon, 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 can persist in unfinished spaces including the attic or an attached garage. If you use the fan setting, your HVAC system can draw this warm air into the rest of your home, forcing the HVAC system to work more to maintain the desired temperature. In serious heat, this could result in needing AC repair more often as wear and tear gets worse.
The reverse can take place in the winter. Cooler spaces like a basement will hold onto cooler air, which will eventually flow into the rest of your home. Keeping the fan on could draw more cold air upward, increasing the amount of heating you need to keep warm.
If you’re still trying to determine 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 might be ideal for you if:
Someone in your household deals with allergies. Allergies and similar respiratory conditions can be stressful on the family. Leaving the fan on should help to improve indoor air quality, helping your family breathe easier.
Your home deals with hot and cold spots. All kinds of homes wrestle with stubborn hot and cold spots that quickly shift to a temperature different from the rest of the house. The fan setting can help minimize these changes by constantly refreshing each room’s ventilation.