As the weather is cooling off, you are probably thinking about how you’ll prepare your heating and cooling. After all, HVAC bills can make up a big chunk of your monthly electric bill. To try and find ways to lower their HVAC bill, some people look closely at their thermostat. Is there a setting they should use to boost efficiency?
Most thermostats come with a ‘Fan’ or ‘Fan On’ setting. But if the fan is going during a typical cycle, what can the fan setting offer for the HVAC system? This guide will help. We’ll review just what the fan setting is and whether you can use it to cut costs in 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 keeps running. Some furnaces may continue to generate heat at a low level with this setting, but in most cases heating or cooling isn’t being made. The ‘Auto’ setting, in contrast, will run the fan through a heating or cooling cycle and switch it off once the cycle is over.
There are advantages and disadvantages to trying the fan setting on your thermostat, and the ideal option should depend on your unique comfort preferences.
Advantages to switching to the Fan/On setting:
- You can keep the temperature in every room more uniform by permitting the fan to keep circulating air.
- Indoor air quality should improve because continuous airflow will keep passing airborne contaminants into the air filter.
- Fewer start-stop cycles for the blower fan helps expand its life span. As 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 nonstop fan can raise your energy expenses by a small margin.
- Continuous airflow could clog your air filter up more quickly, increasing the frequency you should replace it.
Should My Thermostat Be on Fan or Auto in Summer/Winter
Through the summer, warm air may stick around in unfinished spaces such as the attic or an attached garage. If you use the fan setting, your HVAC system may pull this warm air into the rest of your home, forcing the HVAC system to run longer to maintain the desired temperature. In serious heat, this could lead to needing AC repair more regularly as wear and tear grows.
The reverse can occur over the winter. Cooler spaces such as a basement will hold onto cooler air, which will eventually flow into the rest of your home. Leaving the fan running could pump more cold air upward, increasing the amount of heating you need to keep warm.
If you’re still trying to figure out 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 ideal for you if:
Someone in your household has allergies. Allergies and other respiratory conditions can be hard on the family. Leaving the fan on is more likely to enhance indoor air quality, helping your family breathe easier.
Your home has hot and cold spots. Many homes wrestle with persistent hot and cold spots that quickly shift to a temperature different from the rest of the house. The fan setting might help lessen these changes by constantly refreshing each room’s ventilation.