Once the weather begins to cool off, you may be wondering about how you’ll prepare your heating and cooling. After all, HVAC costs frequently add up to a significant portion of your monthly electric bill. To learn new ways to save, some owners take a closer look at their thermostat. Is there a setting they can use to boost efficiency?
The bulk of thermostats come with a ‘Fan’ or ‘Fan On’ setting. But if the fan is running during a typical cycle, what will the fan setting offer for the HVAC system? This guide will help. We’ll share what exactly 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 most thermostats, the fan setting means that the air handler’s blower fan remains on. Some furnaces will run at a low level in this setting, but in most cases heating or cooling isn’t being produced. The ‘Auto’ setting, on the other hand, will start the fan over a heating or cooling cycle and switch it off after the cycle is finished.
There are pros and cons to using the fan setting on your thermostat, and what's ideal can depend on your personal comfort requirements.
Advantages to using the Fan/On setting:
- You can keep the temperature in every room more balanced by allowing the fan to keep generating airflow.
- Indoor air quality can increase as constant airflow will keep passing airborne pollutants into the air filter.
- A smaller amount of start-stop cycles for the system's fan helps expand its life span. As the air handler is usually a component of the furnace, this means you could prevent the need for furnace repair.
Disadvantages to switching to the Fan/On setting:
- A constant fan will likely raise your energy expenses by a small margin.
- Constant airflow can clog your air filter in a shorter amount of time, increasing the frequency you will want to replace it.
Should My Thermostat Be on Fan or Auto in Summer/Winter
During the summer, warm air can linger in unfinished spaces including the attic or an attached garage. If you leave the fan on, your HVAC system may gradually move this warm air into the rest of your home, forcing the HVAC system to work harder to preserve the desired temperature. In serious heat, this can result in needing AC repair more often as wear and tear grows.
The opposite can occur over the winter. Cooler spaces like a basement will hold onto cooler air, which can eventually make its way into the rest of your home. Leaving the fan setting on could draw more cold air upward, increasing the amount of heating you need to stay 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 might be ideal for you if:
Someone in your household suffers from allergies. Allergies and other respiratory conditions can be tough on the family. Leaving the fan on can help to increase indoor air quality, helping your family breathe easier.
Your home deals with hot and cold spots. Many homes wrestle with difficult hot and cold spots that quickly shift to a temperature different from the rest of the house. The fan setting should help minimize these changes by steadily refreshing each room’s ventilation.