When the weather begins to cool off, you might be concerned about how you’ll make the most of your heating and cooling. After all, HVAC expenses routinely add up to a big chunk of your monthly electric bill. To figure out new ways to save, some people look closer at their thermostat. Maybe there’s a setting they should use to increase efficiency?

The majority of thermostats have a ‘Fan’ or ‘Fan On’ setting. But if the fan is on during a normal cycle, what will the fan setting provide for the HVAC system? This guide can help. We’ll walk through precisely what the fan setting is and whether you can use it to save money over the summer or winter.

My Thermostat Has a Fan Setting?

For most thermostats, the fan setting indicates that the air handler’s blower fan keeps running. Certain furnaces may continue to generate heat at a low level in this setting, but in most cases heating or cooling isn’t being produced. The ‘Auto’ setting, conversely, will start the fan during a heating or cooling cycle and switch it off once the cycle is over.

There are pros and cons to trying the fan setting on your thermostat, and the ideal option {will|can|should]] depend on your unique comfort needs.

Advantages to switching to the Fan/On setting:

  • You can keep the temperature throughout your home more uniform by permitting the fan to keep circulating air.
  • Indoor air quality will be highest since steady airflow will keep forcing airborne pollutants through the air filter.
  • A smaller number of start-stop cycles for the blower fan helps extend its life span. Because the air handler is often connected to the furnace, this means you might prevent the need for furnace repair.

Drawbacks to using the Fan/On setting:

  • A constant fan will likely raise your energy costs slightly.
  • Constant airflow could clog your air filter up more quickly, increasing the frequency you will want to replace it.

{Choosing Between|Should My Thermostat Be on|Which Setting for My Thermostat? Fan or Auto in Summer/Winter

In the summer, warm air may linger in unfinished spaces including the attic or an attached garage. If you use the fan setting, your HVAC system can draw this warm air into the rest of your home, compelling the HVAC system to work harder to maintain the desired temperature. In extreme heat, this could lead to needing AC repair more often as wear and tear gets worse.

The opposite can take place in the winter. Cooler spaces such as a basement will hold onto cooler air, which can eventually make its way into the rest of your home. Leaving the fan running will sometimes 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 switch to the fan/on setting, remember that every home and family’s comfort needs are not the same. Leaving the HVAC system’s fan on could be ideal for you if:

Someone in your household suffers from allergies. Allergies and similar respiratory conditions can be tough on the family. Leaving the fan on can help to increase indoor air quality, helping your family breathe easier.

Your home has hot and cold spots. Lots of homes deal with difficult hot and cold spots that quickly evolve to a temperature different from the rest of the house. The fan setting can help minimize these changes by consistently refreshing each room’s ventilation.