Fan setting of the HVAC system

The fan setting on the thermostat controls the HVAC system blower. The blower helps to circulate hot or cold air throughout the home until it reaches the temperature on the thermostat. There are two settings on the thermostat to control the fan-automatic or on.

AUTO means that the fan will automatically turn on only when the system is heating or cooling air. Once the thermostat reaches the desired temperature, the entire system will shut down until the next cycle.
“On” means that when the HVAC system is not heating or cooling air, the fan will always be on and blow air.

According to personal preference, run the fan in the “automatic” or “on” state. We provide the advantages and disadvantages of each setting option, so you can decide which one is best for you.

Advantages of setting the thermostat fan setting to automatic
Keeping the fan running automatically is the most energy-efficient option. The fan only runs when the system is turned on, not continuously.
In summer, the dehumidification effect at home is better. When the electric fan is set to AUTO, the water in the cold coil will drip and be discharged outdoors. If your fan runs continuously, there will be no chance for moisture to drip outside. It will blow back into your home, and your air conditioner will work hard to remove excess moisture from the air.
You need to change the furnace filter more frequently. The air is constantly being cleaned, causing the filter to become dirty faster. A clogged filter will also make the blower work harder and consume more energy.
Disadvantages of setting the thermostat fan setting to “auto”
You may notice that there is less distribution of hot or cold air. Once the air temperature reaches the temperature on the thermostat, the fan will stop transferring the air to the entire house.
Due to frequent starts and stops, the blower fan may wear out more quickly.
Advantages of setting the thermostat to ON
Allow the fan to run uninterruptedly, so that the hot or cold air circulating in the entire house is more evenly distributed. This will help reduce hot or cold spots in your home.
Reduce the pressure on the fan during frequent starts and stops, which may help extend the life of the fan.
If you pass the air through a filter or ultraviolet system, you can make the air in your home cleaner.
Disadvantages of setting the thermostat to “on”
Running the fan continuously may cost you more money. The blower motor of some systems is designed to operate in ON mode, while other systems cannot be used continuously.
In winter, you may find cool air coming out of the ventilation holes. This is because the air temperature is similar to the space temperature and your house will feel cool.
Because of the constant air being blown in, you need to change the furnace filter more frequently.
In the summer, any duct in the attic or near the outer wall can be filled with warm air, blowing hot air into your house. Your HVAC system now needs to run more to offset the extra heat.


Post time: Mar-18-2021