When the weather starts to cool off, you may be wondering about how you’ll make the most of your heating and cooling. After all, HVAC bills frequently add up to a large chunk of your monthly electric bill. To try and find ways to reduce costs, some owners look closely at their thermostat. Maybe there’s a setting they could 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 can the fan setting offer for an HVAC system? This guide can help. We’ll review precisely what the fan setting is and whether you can use it to reduce costs in the summer or winter.

Should I Use My Thermostat's Fan Setting?

For the majority of thermostats, the fan setting indicates that the air handler’s blower fan remains on. Certain furnaces will generate heat at a low level in this setting, but in general heating or cooling isn’t being produced. The ‘Auto’ setting, on the other hand, will start the fan through a heating or cooling cycle and turn it off once the cycle is complete.

There are benefits and drawbacks to switching on the fan setting on your thermostat, and what's ideal {will|can|should]] depend on your personal comfort needs.

Advantages to switching to the Fan/On setting:

  • You can keep the temperature in each room more consistent by enabling the fan to keep generating airflow.
  • Indoor air quality should improve since constant airflow will keep passing airborne particles through the air filter.
  • A smaller number of start-stop cycles for the blower fan helps extend its life span. Since the air handler is usually part of the furnace, this means you might avoid needing furnace repair.

Downsides to using the Fan/On setting:

  • A nonstop fan can raise your energy costs somewhat.
  • Constant airflow could clog your air filter soon, increasing the frequency you’ll need 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 can stick around in unfinished spaces such as the attic or an attached garage. If you use the fan setting, your HVAC system might gradually move this warm air into the rest of your home, compelling the HVAC system to run longer to maintain the desired temperature. In serious heat, this may lead to needing AC repair more regularly as wear and tear grows.

The opposite can occur over the winter. Cooler spaces like a basement will hold onto cooler air, which can eventually make its way into the rest of your home. Leaving the fan running 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 use the fan/on setting, remember that every home and family’s comfort needs are different. Leaving the HVAC system’s fan on could be best 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 is more likely to enhance indoor air quality, helping your family breathe easier.

Your home deals with hot and cold spots. Many homes deal with difficult hot and cold spots that quickly shift 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.