As the weather begins to cool off, you may be wondering about how you’ll take full advantage of your heating and cooling. After all, HVAC bills routinely make up a significant piece of your monthly electric bill. To figure out new ways to reduce costs, some people take a closer look at their thermostat. Could there be a setting they could use to increase efficiency?
The bulk of thermostats include both a ‘Fan’ or ‘Fan On’ setting. But if the fan is going during a normal cycle, what does the fan setting offer for an HVAC system? This guide can help. We’ll walk through just what the fan setting is and whether you can use it to save money in the summer or winter.
What Is the Fan Setting on My Thermostat?
For the majority of thermostats, the fan setting means that the HVAC blower fan keeps running. Certain furnaces can run at a low level with this setting, but in general heating or cooling isn’t being generated. The ‘Auto’ setting, on the other hand, will run the fan over a heating or cooling cycle and switch it off after the cycle is over.
There are advantages and disadvantages to trying the fan setting on your thermostat, and what's ideal will depend on your distinct comfort needs.
Advantages to trying the Fan/On setting:
- You can keep the temperature in each room more consistent by allowing the fan to keep circulating air.
- Indoor air quality will be highest because steady airflow will keep passing airborne pollutants into the air filter.
- A smaller amount of start-stop cycles for the system's fan helps lengthen its life span. As the air handler is typically connected to the furnace, this means you might minimize the risk of needing furnace repair.
Disadvantages to switching to the Fan/On setting:
- A continuous fan will likely add to your energy bills somewhat.
- Nonstop airflow may 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
Through the summer, warm air will sometimes linger in unfinished spaces such as the attic or an attached garage. If you leave the fan on, your HVAC system might pull this warm air into the rest of your home, pushing the HVAC system to work harder to keep up with the desired temperature. In extreme heat, this can lead to needing AC repair more regularly as wear and tear increases.
The reverse can take place over the winter. Cooler spaces like a basement will hold onto cooler air, which can eventually flow 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 remain warm.
If you’re still trying to decide 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 may be ideal for you if:
Someone in your household suffers from allergies. Allergies and other respiratory conditions can be hard on the family. Leaving the fan on is more likely to improve indoor air quality, helping your family breathe easier.
Your home has hot and cold spots. All kinds of homes deal with difficult 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 ventilation.