As the weather is cooling off, you might be concerned about how you’ll take full advantage of your heating and cooling. After all, HVAC bills routinely contribute a large chunk of your monthly electric bill. To try and find ways to lower their HVAC bill, some owners look closely at their thermostat. Maybe there’s a setting they could use to boost efficiency?
Most thermostats have a ‘Fan’ or ‘Fan On’ setting. But if the fan is running during a normal cycle, what can the fan setting provide for the HVAC system? This guide can help. We’ll review just what the fan setting is and whether you can use it to reduce costs over the summer or winter.
What Is the Fan Setting on My Thermostat?
For the majority of thermostats, the fan setting means that the system's blower fan stays on. Certain 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 turn on the fan through a heating or cooling cycle and shut it off when the cycle is complete.
There are advantages and disadvantages to trying the fan setting on your thermostat, and the ideal option should depend on your distinct comfort preferences.
Advantages to utilizing the Fan/On setting:
- You can keep the temperature in each room more consistent by enabling the fan to keep running.
- Indoor air quality will be highest since steady airflow will keep passing airborne pollutants through the air filter.
- A smaller number of start-stop cycles for the blower fan helps expand its life span. As the air handler is typically part of the furnace, this means you can prevent the need for furnace repair.
Downsides to switching to the Fan/On setting:
- A constant fan can raise your energy expenses slightly.
- Continuous airflow can 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
Through the summer, warm air can stick around 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, compelling the HVAC system to work more to maintain the preferred temperature. In severe heat, this can result in needing AC repair more quickly as wear and tear grows.
The opposite can take place during the winter. Cooler spaces such as a basement will hold onto cooler air, which can eventually drift into the rest of your home. Leaving the fan running may pump more cold air upward, increasing the amount of heating you need to remain warm.
If you’re still trying to decide 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 could work for you if:
Someone in your household suffers from allergies. Allergies and other respiratory conditions can be stressful on the family. Leaving the fan on can help to enhance indoor air quality, helping your family breathe easier.
Your home deals with hot and cold spots. All kinds of homes wrestle with persistent hot and cold spots that quickly return to a temperature different from the rest of the house. The fan setting can help limit these changes by consistently refreshing each room’s airflow.