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“Auto” or “On”? Does leaving the AC fan on waste electricity?

Does leaving the AC fan on waste electricity?  

Whether it’s the sweltering summer months or the bitter cold of winter, we are all striving to maintain a comfortable temperature within our homes. Often, we use our central air systems, which come equipped with thermostats that have either an “on” or “auto” setting regarding the fan. The fan will spin to move air within the house through the vents or ducts.   

There is no clear indication as to what the better option may be when it comes to saving electricity and keeping the home cooler or warmer. It is very dependent on the current weather and how long you may want to keep the fan on. However, there are various things to consider when deciding what to leave the setting at. It may seem like a small matter, but the energy the fan is using can leave a significant impact on your overall energy consumption for the year.  

Running the fan and keeping it set to “on” seems to have some positive benefits. When the fan is on, it makes the house feel less stuffy, and pushes air to the entire home from a central source, so it is easy to use. The air flow can make you feel better and less uncomfortable. 

However, this is not the case. The ducts often run through the attic space and walls within the home, which is significantly warmer due to being closer to the outside walls. The fan being on when the AC is not in use will result in blowing hot air through the house. This, in turn, means the AC will kick on more often and work harder to cool the air.  

Most fans are quite energy efficient, especially in newer systems. The fan itself runs about as much energy as a refrigerator would. This can still add up to $50 a month, or $600 a year. This cost can be even higher if you consider the AC unit working harder to counteract the effects the fan may have.  

There are times though that using the fan has benefits. When you want to use the fan consider the outside temperature and things like if your house bakes in the sun all day. In the summer you can use the fan in the early morning, especially for getting the air flowing and then using the AC. It isn’t recommended to leave the fan on when you aren’t going to be home to monitor it or turn it off when needed. 

In short, leaving the fan on during certain seasons is going to do more harm than good for both your comfort and energy bill. To make sure your central air units are running efficiently and seeing what settings might be best for your home, it is recommended to consult an expert. For all questions related to heating and cool, big, or small, contact us here!