When the weather starts to cool off, you may be concerned about how you’ll make the most of your heating and cooling. After all, HVAC bills frequently contribute a large chunk of your monthly electric bill. To try and find ways to reduce costs, some homeowners look closer 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 running during a normal cycle, what does the fan setting offer for an HVAC system? This guide will help. We’ll walk through precisely what the fan setting is and when you can use it to cut costs during the summer or winter.

Should I Use My Thermostat's Fan Setting?

For the bulk of thermostats, the fan setting signifies that the system's blower fan stays on. A few furnaces will generate heat at a low level in this setting, but in most cases heating or cooling isn’t being produced. The ‘Auto’ setting, in contrast, will turn on the fan over a heating or cooling cycle and switch it off once the cycle is over.

There are benefits and drawbacks to using the fan setting on your thermostat, and the ideal option {will|can|should]] depend on your distinct comfort needs.

Advantages to switching to the Fan/On setting:

  • You can keep the temperature throughout your home more consistent by permitting the fan to keep generating airflow.
  • Indoor air quality will be highest as steady airflow will keep moving airborne particles into the air filter.
  • A smaller number of start-stop cycles for the blower fan helps lengthen its life span. As the air handler is often connected to the furnace, this means you can minimize the risk of needing furnace repair.

Drawbacks to using the Fan/On setting:

  • A nonstop fan will likely add to your energy costs somewhat.
  • Continuous 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 Each Season

In the summer, warm air may linger in unfinished spaces such as 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 more to maintain the desired temperature. In severe heat, this could lead to needing AC repair more quickly as wear and tear increases.

The reverse can take place over the winter. Cooler spaces like a basement will hold onto cooler air, which will eventually make its way into the rest of your home. Leaving the fan running will sometimes pump 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, remember that every home and family’s comfort needs are different. Leaving the HVAC system’s fan on might be best for you if:

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

Your home deals with hot and cold spots. Many homes wrestle with persistent hot and cold spots that quickly evolve to a temperature different from the rest of the house. The fan setting should help limit these changes by steadily refreshing each room’s ventilation.