Once the weather starts to cool off, you are probably wondering about how you’ll prepare your heating and cooling. After all, HVAC expenses frequently make up a big chunk of your monthly electric bill. To figure out new ways to save, some people look closer at their thermostat. Maybe there’s a setting they should use to improve efficiency?

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

How Do I Access the Fan Setting on My Thermostat?

For most thermostats, the fan setting indicates that the system's blower fan keeps running. A few furnaces can operate at a low level with this setting, but in general heating or cooling isn’t being made. The ‘Auto’ setting, in contrast, will run the fan through a heating or cooling cycle and switch it off when the cycle is over.

There are pros and cons to trying the fan setting on your thermostat, and what's ideal {will|can|should]] depend on your personal comfort requirements.

Advantages to trying the Fan/On setting:

  • You can keep the temperature in every room more balanced by enabling the fan to keep circulating air.
  • Indoor air quality should improve because continuous airflow will keep moving airborne contaminants through the air filter.
  • Fewer start-stop cycles for the system's fan helps extend its life span. As the air handler is often a component of the furnace, this means you might avoid needing furnace repair.

Drawbacks to switching to the Fan/On setting:

  • A constant fan could increase your energy costs by a small margin.
  • Nonstop airflow may clog your air filter up more quickly, 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 persist in unfinished spaces including the attic or an attached garage. If you use the fan setting, your HVAC system might pull 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 can result in needing AC repair more regularly as wear and tear increases.

The reverse can happen over the winter. Cooler spaces like a basement will hold onto cooler air, which may eventually make its way into the rest of your home. Leaving the fan running may pull more cold air upward, increasing the amount of heating you need to keep warm.

If you’re still trying to decide if you should try the fan/on setting, remember that every home and family’s comfort needs will vary. Leaving the HVAC system’s fan on could be ideal for you if:

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

Your home experiences hot and cold spots. Many homes deal with stubborn hot and cold spots that quickly return to a temperature different from the rest of the house. The fan setting should help lessen these changes by consistently refreshing each room’s ventilation.