When the weather begins to cool off, you may be thinking about how you’ll take full advantage of your heating and cooling. After all, HVAC expenses routinely contribute a large piece of your monthly electric bill. To try and find ways to lower their HVAC bill, some people look closer at their thermostat. Could there be a setting they should use to boost efficiency?
Most thermostats include both a ‘Fan’ or ‘Fan On’ setting. But if the fan is going during a regular cycle, what does the fan setting provide for your HVAC system? This guide can help. We’ll share precisely what the fan setting is and how you can use it to cut costs in 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 remains on. Some furnaces can run at a low level with this setting, but for the most part heating or cooling isn’t being made. The ‘Auto’ setting, conversely, will turn on the fan during a heating or cooling cycle and turn it off when the cycle is complete.
There are benefits and drawbacks to using the fan setting on your thermostat, and whether you do or don’t {will|can|should]] depend on your unique comfort requirements.
Advantages to using the Fan/On setting:
- You can keep the temperature in every room more uniform by permitting the fan to keep generating airflow.
- Indoor air quality can increase since constant airflow will keep forcing airborne particles into the air filter.
- Fewer start-stop cycles for the blower fan helps lengthen its life span. Since the air handler is typically part of the furnace, this means you can minimize the risk of needing furnace repair.
Downsides to using the Fan/On setting:
- A constant fan will likely raise your energy expenses somewhat.
- Nonstop airflow could clog your air filter up more quickly, increasing the frequency you will want to replace it.
Should My Thermostat Be on Fan or Auto in Summer/Winter
During the summer, warm air will sometimes stick around in unfinished spaces including the attic or an attached garage. If you keep the fan running, your HVAC system can gradually move this warm air into the rest of your home, forcing the HVAC system to work harder to preserve the preferred temperature. In severe heat, this can result in needing AC repair more quickly as wear and tear gets worse.
The opposite can happen in the winter. Cooler spaces such as a basement will hold onto cooler air, which will eventually drift into the rest of your home. Keeping the fan on could pull more cold air upward, increasing the amount of heating you need to keep warm.
If you’re still trying to determine if you should use the fan/on setting, don’t forget that every home and family’s comfort needs are different. Leaving the HVAC system’s fan on might work for you if:
Someone in your household suffers from allergies. Allergies and other respiratory conditions can be tough on the family. Leaving the fan on should help to improve indoor air quality, helping your family breathe easier.
Your home has hot and cold spots. Lots 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 should help minimize these changes by consistently refreshing each room’s airflow.