Once the weather is cooling off, you are probably concerned about how you’ll take full advantage of your heating and cooling. After all, HVAC expenses routinely contribute a large portion of your monthly electric bill. To learn new ways to save, some people look closely at their thermostat. Is there a setting they could use to improve efficiency?
Most thermostats have a ‘Fan’ or ‘Fan On’ setting. But if the fan is on during a typical cycle, what does the fan setting provide for an HVAC system? This guide should help. We’ll walk through just what the fan setting is and how you can use it to cut costs during 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. Certain furnaces can generate heat at a low level with this setting, but in most cases heating or cooling isn’t being produced. The ‘Auto’ setting, in contrast, will turn on the fan through a heating or cooling cycle and shut it off after the cycle is complete.
There are advantages and disadvantages to trying the fan setting on your thermostat, and what's ideal {will|can|should]] depend on your personal comfort requirements.
Advantages to using the Fan/On setting:
- You can keep the temperature throughout your home more uniform by permitting the fan to keep running.
- Indoor air quality can increase since continuous airflow will keep moving airborne contaminants into the air filter.
- A smaller amount of start-stop cycles for the blower fan helps lengthen its life span. Because the air handler is often part of the furnace, this means you could avoid needing furnace repair.
Downsides to using the Fan/On setting:
- A nonstop fan will likely add to your energy bills slightly.
- Continuous airflow could clog your air filter soon, increasing the frequency you will want to replace it.
Should My Thermostat Be on Fan or Auto in Summer/Winter
Through the summer, warm air can persist in unfinished spaces including 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, pushing the HVAC system to run longer to preserve the set temperature. In severe heat, this could lead to needing AC repair more quickly as wear and tear gets worse.
The opposite can happen in the winter. Cooler spaces like a basement will hold onto cooler air, which may eventually flow into the rest of your home. Keeping the fan on will sometimes pump 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 different. Leaving the HVAC system’s fan on may be ideal for you if:
Someone in your household has allergies. Allergies and other respiratory conditions can be stressful on the family. Leaving the fan on should help to improve indoor air quality, helping your family breathe easier.
Your home deals with hot and cold spots. All kinds of homes deal with persistent hot and cold spots that quickly return 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.
