When the weather begins to cool off, you are probably concerned about how you’ll prepare your heating and cooling. After all, HVAC bills frequently contribute a big chunk of your monthly electric bill. To try and find ways to lower their HVAC bill, some homeowners look closer at their thermostat. Maybe there’s a setting they could use to improve efficiency?
The majority of thermostats have a ‘Fan’ or ‘Fan On’ setting. But if the fan is on during a normal cycle, what can the fan setting provide for your HVAC system? This guide should help. We’ll walk through precisely what the fan setting is and when you can use it to cut costs over the summer or winter.
What Is the Fan Setting on My Thermostat?
For the majority of thermostats, the fan setting signifies that the system's blower fan stays on. A few furnaces will generate heat at a low level in this setting, but in general heating or cooling isn’t being made. The ‘Auto’ setting, in contrast, will turn on the fan over a heating or cooling cycle and turn it off after the cycle is finished.
There are advantages and disadvantages to trying the fan setting on your thermostat, and whether you do or don’t should depend on your personal comfort needs.
Advantages to switching to the Fan/On setting:
- You can keep the temperature throughout your home more consistent by permitting the fan to keep circulating air.
- Indoor air quality will be highest because steady airflow will keep forcing airborne pollutants through the air filter.
- A smaller number of start-stop cycles for the system's fan helps extend its life span. Since the air handler is typically connected to the furnace, this means you might minimize the risk of needing furnace repair.
Downsides to utilizing the Fan/On setting:
- A continuous fan could increase your energy expenses by a small margin.
- Constant airflow could clog your air filter up more quickly, increasing the frequency you should replace it.
Should My Thermostat Be on Fan or Auto in Summer/Winter
Through the summer, warm air can linger in unfinished spaces such as the attic or an attached garage. If you keep the fan running, your HVAC system can draw this warm air into the rest of your home, compelling the HVAC system to work harder to maintain the preferred temperature. In extreme heat, this may lead to needing AC repair more regularly as wear and tear gets worse.
The reverse can occur over the winter. Cooler spaces like a basement will hold onto cooler air, which will eventually make its way into the rest of your home. Leaving the fan running may draw more cold air upward, increasing the amount of heating you need to remain warm.
If you’re still trying to decide if you should switch to the fan/on setting, don’t forget that every home and family’s comfort needs are different. Leaving the HVAC system’s fan on could be best for you if:
Someone in your household has allergies. Allergies and similar respiratory conditions can be stressful 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. All kinds of homes deal with persistent 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.