As the weather begins to cool off, you might be wondering about how you’ll prepare your heating and cooling. After all, HVAC expenses can contribute a large piece of your monthly electric bill. To learn new ways to lower their HVAC bill, some homeowners look closely at their thermostat. Is there a setting they can use to improve efficiency?
The majority of thermostats come with 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 will help. We’ll review what exactly the fan setting is and when you can use it to save money over the summer or winter.
What Is the Fan Setting on My Thermostat?
For the bulk of thermostats, the fan setting means that the system's blower fan stays on. Certain furnaces may continue to generate heat at a low level in this setting, but in general heating or cooling isn’t being generated. The ‘Auto’ setting, conversely, will start the fan during a heating or cooling cycle and shut it off once the cycle is over.
There are advantages and disadvantages to trying the fan setting on your thermostat, and the ideal option can depend on your personal comfort preferences.
Advantages to trying the Fan/On setting:
- You can keep the temperature in every room more consistent by allowing the fan to keep running.
- Indoor air quality will be highest since continuous airflow will keep forcing airborne particles through the air filter.
- A smaller amount of start-stop cycles for the blower fan helps lengthen its life span. Since the air handler is often connected to the furnace, this means you might avoid needing furnace repair.
Downsides to switching to the Fan/On setting:
- A constant fan can increase your energy costs somewhat.
- Nonstop airflow could clog your air filter up more quickly, increasing the frequency you’ll need to replace it.
Should My Thermostat Be on Fan or Auto in Summer/Winter
In the summer, warm air can persist in unfinished spaces including the attic or an attached garage. If you leave the fan on, your HVAC system can gradually move this warm air into the rest of your home, compelling the HVAC system to run longer to preserve the preferred temperature. In extreme heat, this could result in needing AC repair more quickly as wear and tear grows.
The reverse can happen during the winter. Cooler spaces like a basement will hold onto cooler air, which will eventually flow into the rest of your home. Leaving the fan running could pull 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 switch to the fan/on setting, remember that every home and family’s comfort needs are different. 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 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. Many homes deal with persistent hot and cold spots that quickly shift to a temperature different from the rest of the house. The fan setting should help lessen these changes by consistently refreshing each room’s airflow.