As the weather starts to cool off, you are probably thinking about how you’ll take full advantage of your heating and cooling. After all, HVAC bills can add up to a large piece of your monthly electric bill. To try and find ways to save, some homeowners look closely at their thermostat. Could there be a setting they could use to boost efficiency?
The bulk of thermostats come with a ‘Fan’ or ‘Fan On’ setting. But if the fan is going during a regular cycle, what does 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 reduce costs during the summer or winter.
What Is the Fan Setting on My Thermostat?
For the majority of thermostats, the fan setting means that the HVAC blower fan stays on. Certain furnaces will operate at a low level with this setting, but for the most part heating or cooling isn’t being made. The ‘Auto’ setting, in contrast, will turn on the fan through a heating or cooling cycle and shut it off when the cycle is over.
There are pros and cons to switching on the fan setting on your thermostat, and what's ideal will depend on your distinct comfort requirements.
Advantages to switching to the Fan/On setting:
- You can keep the temperature throughout your home more consistent by allowing the fan to keep generating airflow.
- Indoor air quality should improve since constant airflow will keep forcing airborne contaminants into the air filter.
- A smaller amount of start-stop cycles for the blower fan helps expand its life span. Since the air handler is typically connected to the furnace, this means you might prevent the need for furnace repair.
Drawbacks to using the Fan/On setting:
- A continuous fan could add to your energy expenses by a small margin.
- Continuous airflow may clog your air filter in a shorter amount of time, increasing the frequency you will want to replace it.
Should My Thermostat Be on Fan or Auto in Summer/Winter
During the summer, warm air will sometimes linger in unfinished spaces like the attic or an attached garage. If you keep the fan running, your HVAC system may pull this warm air into the rest of your home, pushing the HVAC system to run longer to preserve the set temperature. In serious heat, this can lead to needing AC repair more regularly as wear and tear increases.
The opposite can happen 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 pull more cold air upward, increasing the amount of heating you need to remain warm.
If you’re still trying to decide if you should use the fan/on setting, keep in mind that every home and family’s comfort needs are not the same. Leaving the HVAC system’s fan on could work for you if:
Someone in your household deals with allergies. Allergies and other respiratory conditions can be hard on the family. Leaving the fan on can help to improve indoor air quality, helping your family breathe easier.
Your home deals with hot and cold spots. All kinds of homes deal with difficult hot and cold spots that quickly return to a temperature different from the rest of the house. The fan setting can help minimize these changes by steadily refreshing each room’s airflow.