When the weather is cooling off, you may be concerned about how you’ll prepare your heating and cooling. After all, HVAC costs can add up to a significant portion of your monthly electric bill. To try and find ways to reduce costs, some people look closely at their thermostat. Maybe there’s a setting they could use to improve efficiency?

The bulk of thermostats have a ‘Fan’ or ‘Fan On’ setting. But if the fan is going during a typical cycle, what does the fan setting provide for an HVAC system? This guide will help. We’ll walk through what exactly the fan setting is and whether you can use it to save money in the summer or winter.

Should I Use My Thermostat’s Fan Setting?

For most thermostats, the fan setting means that the air handler’s blower fan keeps running. Some furnaces may continue to operate at a low level in this setting, but for the most part heating or cooling isn’t being made. The ‘Auto’ setting, on the other hand, 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 trying the fan setting on your thermostat, and what’s ideal {will|can|should]] depend on your unique comfort needs.

Advantages to utilizing the Fan/On setting:

  • You can keep the temperature throughout your home more uniform by enabling the fan to keep circulating air.
  • Indoor air quality should improve because continuous airflow will keep passing airborne contaminants through the air filter.
  • A smaller amount of start-stop cycles for the blower fan helps lengthen its life span. Since the air handler is usually part of the furnace, this means you can avoid needing furnace repair.

Drawbacks to utilizing the Fan/On setting:

  • A nonstop fan will likely increase your energy expenses somewhat.
  • Constant airflow may clog your air filter soon, 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 leave the fan on, your HVAC system might draw this warm air into the rest of your home, pushing the HVAC system to work more to maintain the set temperature. In severe heat, this could result in needing AC repair more quickly as wear and tear grows.

The reverse can occur during the winter. Cooler spaces such as a basement will hold onto cooler air, which may eventually make its way into the rest of your home. Keeping the fan on will sometimes pull more cold air upward, increasing the amount of heating you need to stay warm.

If you’re still trying to figure out 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 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 is more likely to increase indoor air quality, helping your family breathe easier.

Your home has hot and cold spots. Many homes deal with stubborn hot and cold spots that quickly evolve to a temperature different from the rest of the house. The fan setting should help minimize these changes by steadily refreshing each room’s supply of air.