As the weather starts to cool off, you might be concerned about how you’ll make the most of your heating and cooling. After all, HVAC expenses routinely make up a large piece of your monthly electric bill. To try and find ways to lower their HVAC bill, some homeowners take a closer look at their thermostat. Is there a setting they should use to boost efficiency?

The majority of thermostats have a ‘Fan’ or ‘Fan On’ setting. But if the fan is going during a typical cycle, what can the fan setting offer for the HVAC system? This guide will help. We’ll share just what the fan setting is and how you can use it to cut costs in the summer or winter.

How Do I Access the Fan Setting on My Thermostat?

For most thermostats, the fan setting signifies that the system's blower fan stays on. Some furnaces may continue to generate heat at a low level with this setting, but in most cases heating or cooling isn’t being made. The ‘Auto’ setting, on the other hand, will start the fan during a heating or cooling cycle and shut it off when the cycle is over.

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 each room more consistent by enabling the fan to keep circulating air.
  • Indoor air quality will be highest because steady 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 typically connected to the furnace, this means you can minimize the risk of needing furnace repair.

Drawbacks to switching to the Fan/On setting:

  • A continuous fan will likely increase your energy expenses by a small margin.
  • Nonstop airflow can clog your air filter up more quickly, increasing the frequency you should 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 will sometimes persist in unfinished spaces such as the attic or an attached garage. If you keep the fan running, your HVAC system might draw this warm air into the rest of your home, pushing the HVAC system to work more to preserve the desired temperature. In serious heat, this may lead to needing AC repair more quickly as wear and tear increases.

The opposite can occur 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 setting on may pump more cold air upward, increasing the amount of heating you need to keep 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 will vary. Leaving the HVAC system’s fan on could work for you if:

Someone in your household has allergies. Allergies and other respiratory conditions can be tough on the family. Leaving the fan on should help to enhance indoor air quality, helping your family breathe easier.

Your home experiences hot and cold spots. All kinds of homes wrestle with persistent 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 steadily refreshing each room’s supply of air.