Seasonal Guide: Should My Thermostat Be on Auto or Fan?

Once the weather is cooling off, you might be thinking about how you’ll take full advantage of your heating and cooling. After all, HVAC bills frequently contribute a big piece of your monthly electric bill. To learn new ways to lower their HVAC bill, some owners take a closer look at their thermostat. Is there a setting they should use to improve efficiency?

The majority of thermostats include both a ‘Fan’ or ‘Fan On’ setting. But if the fan is on during a typical cycle, what will the fan setting offer for an HVAC system? This guide can help. We’ll share just what the fan setting is and how you can use it to cut 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 HVAC blower fan keeps running. A few furnaces will 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 switch it off after the cycle is over.

There are pros and cons to switching on 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 in each room more uniform by permitting the fan to keep circulating air.
• Indoor air quality can increase as steady airflow will keep forcing airborne particles through the air filter.
• A smaller amount of start-stop cycles for the blower fan helps lengthen its life span. Because the air handler is usually connected to the furnace, this means you might prevent the need for furnace repair.

Downsides to switching to the Fan/On setting:

• A nonstop fan will likely raise your energy expenses by a small margin.
• Continuous airflow can clog your air filter soon, 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

Through the summer, warm air can linger 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 keep up with the set temperature. In extreme heat, this could lead to needing AC repair more regularly as wear and tear grows.

The reverse 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. Keeping the fan on could draw 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, don’t forget that every home and family’s comfort needs will vary. Leaving the HVAC system’s fan on may be ideal for you if:

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

Your home deals with 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 should help minimize these changes by consistently refreshing each room’s supply of air.