Once the weather begins to cool off, you might be wondering about how you’ll prepare your heating and cooling. After all, HVAC expenses can make up a big chunk 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 could use to boost efficiency?
Most thermostats include both a ‘Fan’ or ‘Fan On’ setting. But if the fan is going during a normal cycle, what will the fan setting provide for an HVAC system? This guide will help. We’ll share precisely what the fan setting is and whether you can use it to cut costs over the summer or winter.
What Is the Fan Setting on My Thermostat?
For most thermostats, the fan setting means that the HVAC blower fan keeps running. A few furnaces will run at a low level with this setting, but in general heating or cooling isn’t being made. The ‘Auto’ setting, conversely, will start the fan during a heating or cooling cycle and turn it off after the cycle is over.
There are pros and cons to using the fan setting on your thermostat, and the ideal option will depend on your unique comfort requirements.
Advantages to trying the Fan/On setting:
- You can keep the temperature in each room more balanced by enabling the fan to keep generating airflow.
- Indoor air quality should improve since steady airflow will keep moving airborne contaminants into the air filter.
- A smaller number of start-stop cycles for the system's fan helps extend its life span. Because the air handler is typically part of the furnace, this means you could prevent the need for furnace repair.
Drawbacks to using the Fan/On setting:
- A continuous fan could increase your energy costs by a small margin.
- Nonstop airflow may 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 linger in unfinished spaces such as the attic or an attached garage. If you leave the fan on, your HVAC system might draw 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 may lead to needing AC repair more often as wear and tear gets worse.
The reverse can happen 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 setting on will sometimes draw more cold air upward, increasing the amount of heating you need to keep warm.
If you’re still trying to determine if you should try the fan/on setting, remember that every home and family’s comfort needs will vary. Leaving the HVAC system’s fan on might be ideal for you if:
Someone in your household deals with allergies. Allergies and other respiratory conditions can be hard on the family. Leaving the fan on should help to increase 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 can help lessen these changes by steadily refreshing each room’s supply of air.