As the weather starts to cool off, you may be wondering about how you’ll prepare your heating and cooling. After all, HVAC bills routinely add up to a large portion of your monthly electric bill. To figure out new ways to save, some homeowners look closely at their thermostat. Maybe there’s a setting they can use to boost efficiency?

Most thermostats include both a ‘Fan’ or ‘Fan On’ setting. But if the fan is going during a regular cycle, what can the fan setting offer for your HVAC system? This guide will help. We’ll walk through just what the fan setting is and how you can use it to save money over the summer or winter.

My Thermostat Has a Fan Setting?

For the bulk of thermostats, the fan setting means that the air handler’s blower fan keeps running. Some furnaces can generate heat 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 start the fan during a heating or cooling cycle and switch it off once the cycle is complete.

There are pros and cons to switching on the fan setting on your thermostat, and whether you do or don’t {will|can|should]] depend on your distinct comfort needs.

Advantages to trying the Fan/On setting:

  • You can keep the temperature in every room more uniform by allowing the fan to keep running.
  • Indoor air quality will be highest because continuous airflow will keep forcing airborne particles into the air filter.
  • A smaller amount of start-stop cycles for the blower fan helps extend its life span. Because the air handler is often a component of the furnace, this means you could prevent the need for furnace repair.

Disadvantages to using the Fan/On setting:

  • A continuous fan can add to your energy expenses somewhat.
  • Constant airflow could clog your air filter up more quickly, 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 Each Season

During the summer, warm air may persist in unfinished spaces including the attic or an attached garage. If you use the fan setting, your HVAC system may draw this warm air into the rest of your home, pushing the HVAC system to work more to preserve the set temperature. In extreme heat, this may result in needing AC repair more quickly as wear and tear increases.

The opposite can take place in the winter. Cooler spaces such as a basement will hold onto cooler air, which can eventually drift into the rest of your home. Keeping the fan on could pump 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, don’t forget that every home and family’s comfort needs are not the same. Leaving the HVAC system’s fan on may be ideal for you if:

Someone in your household deals with allergies. Allergies and similar 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 experiences hot and cold spots. Many homes deal with persistent hot and cold spots that quickly shift to a temperature different from the rest of the house. The fan setting should help lessen these changes by constantly refreshing each room’s ventilation.