As the weather starts to cool off, you might be concerned about how you’ll take full advantage of your heating and cooling. After all, HVAC expenses frequently contribute a big portion of your monthly electric bill. To try and find ways to lower their HVAC bill, some homeowners look closer at their thermostat. Could there be a setting they can use to increase efficiency?
The majority of thermostats come with a ‘Fan’ or ‘Fan On’ setting. But if the fan is on during a normal cycle, what does the fan setting offer for the 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.
What Is the Fan Setting on My Thermostat?
For the bulk of thermostats, the fan setting indicates that the system's blower fan remains on. Certain furnaces may continue to operate at a low level with 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 through a heating or cooling cycle and shut it off after the cycle is finished.
There are advantages and disadvantages to trying the fan setting on your thermostat, and the ideal option should depend on your distinct comfort preferences.
Advantages to trying the Fan/On setting:
- You can keep the temperature in each room more uniform by enabling the fan to keep running.
- Indoor air quality can increase since steady airflow will keep forcing airborne contaminants through the air filter.
- A smaller amount of start-stop cycles for the system's fan helps lengthen its life span. Since the air handler is typically connected to the furnace, this means you can avoid needing furnace repair.
Downsides to using the Fan/On setting:
- A continuous fan will likely raise your energy bills slightly.
- Constant airflow could clog your air filter up more quickly, increasing the frequency you’ll need to replace it.
Should My Thermostat Be on Fan or Auto in Summer/Winter
During the summer, warm air can persist in unfinished spaces such as 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, compelling the HVAC system to work more to maintain the set temperature. In severe heat, this may result in needing AC repair more often as wear and tear increases.
The reverse can occur during the winter. Cooler spaces like a basement will hold onto cooler air, which can 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 remain warm.
If you’re still trying to figure out if you should switch to 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 has allergies. Allergies and other respiratory conditions can be tough on the family. Leaving the fan on should help to improve indoor air quality, helping your family breathe easier.
Your home deals with hot and cold spots. Many homes deal with difficult hot and cold spots that quickly shift to a temperature different from the rest of the house. The fan setting can help minimize these changes by constantly refreshing each room’s airflow.