Once the weather starts to cool off, you are probably concerned about how you’ll take full advantage of your heating and cooling. After all, HVAC bills can add up to a big portion of your monthly electric bill. To figure out new ways to lower their HVAC bill, some owners look closely at their thermostat. Could there be a setting they can use to improve efficiency?
The bulk of thermostats have a ‘Fan’ or ‘Fan On’ setting. But if the fan is on during a normal cycle, what does the fan setting provide for an HVAC system? This guide can help. We’ll share precisely what the fan setting is and when you can use it to reduce costs in the summer or winter.
What Is the Fan Setting on My Thermostat?
For the bulk of thermostats, the fan setting means that the air handler’s blower fan stays on. A few furnaces will operate at a low level in this setting, but for the most part heating or cooling isn’t being made. The ‘Auto’ setting, conversely, will run the fan over a heating or cooling cycle and switch it off when the cycle is over.
There are benefits and drawbacks to switching on the fan setting on your thermostat, and the ideal option should depend on your unique comfort preferences.
Advantages to trying the Fan/On setting:
- You can keep the temperature in each room more balanced by enabling the fan to keep running.
- Indoor air quality can increase since constant airflow will keep moving airborne contaminants through the air filter.
- Fewer start-stop cycles for the HVAC fan helps lengthen its life span. Since the air handler is often a component of the furnace, this means you can minimize the risk of needing furnace repair.
Drawbacks to utilizing the Fan/On setting:
- A constant fan will likely raise your energy expenses by a small margin.
- Continuous 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
In the summer, warm air can linger in unfinished spaces including the attic or an attached garage. If you keep the fan running, your HVAC system can gradually move this warm air into the rest of your home, forcing the HVAC system to work more to keep up with the set temperature. In severe heat, this could lead to needing AC repair more regularly as wear and tear grows.
The opposite can occur over the winter. Cooler spaces like a basement will hold onto cooler air, which may eventually flow into the rest of your home. Leaving the fan setting on may draw more cold air upward, increasing the amount of heating you need to stay warm.
If you’re still trying to determine if you should use the fan/on setting, keep in mind 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 has allergies. Allergies and similar respiratory conditions can be tough 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. Lots of homes deal with difficult hot and cold spots that quickly return to a temperature different from the rest of the house. The fan setting should help limit these changes by steadily refreshing each room’s ventilation.