The average kWh in the US costs about $0.12 so it costs about $43 per month, or about $520 per year, to run a fan continuously.
The average unit has a 500 watt fan, which uses almost as much energy over the course of the year as a refrigerator, resulting in a $50/month bill. During the summer months, the ducts in your attic and close to your walls can fill with warm air, resulting in the fan blowing hot air into your house.
Some homeowners naturally worry about the risks of a breakdown if they run the fan all the time, but this will not be a concern for you if your HVAC system was properly installed and maintained.
Since the AUTO setting means the fan is only engaged when the system is on, rather than constantly blowing, AUTO is the most energy-efficient option between the two settings.
This approach can reduce wear and tear on the air conditioning equipment because the fan doesn't have to start and stop as often. Running the fan on the AC all the time also helps maintain a more consistent and even temperature throughout your home because air is constantly circulating, eliminating hot and cold spots.
Therefore, the fan uses about 360 kWh per month in the ON mode. The average kWh in the US costs about $0.12 so it costs about $43 per month, or about $520 per year, to run a fan continuously.
Generally, running the fan for 15-20 minutes per hour is sufficient for adequate air circulation. However, longer fan run times may be necessary for specific conditions like hot and humid weather or improved air filtration.
Keeping your fan on AUTO is the most energy-efficient option. The fan only runs when the system is on and not continuously. There is better dehumidification in your home during the summer months. When your fan is set to AUTO, moisture from cold cooling coils can drip and be drained outside.
Constantly running your fan will move a lot more air through your filter. It'll need to be changed more often. The upside is that the air your family breathes will be cleaner and healthier, and so will your home.
"Most electrical fans are designed to be able to run continuously for several hours at a time, for example overnight or during the day, but you'll also need to keep in mind doing that continuously for long periods can cause wear and tear on the motor and other components, shortening its lifespan," continues David.
Running the HVAC fan by itself usually does not bring in outside air. The fan's job is to move air around your home. When you set your HVAC to “fan” mode, it circulates the air that's already inside your house. However, some systems have a fresh air intake that can bring in outside air when the fan is running.
Turning your thermostat to the wrong setting by focusing solely on temperature rather than humidity is a common mistake. For example, running your AC unit in fan mode might increase the airflow in your home, but it will also increase the humidity level.
Leaving the fan running reduces wear and tear on the motor since it's not starting and stopping repeatedly. It's also beneficial to boost filtration, but leaving it on this setting has more drawbacks than benefits. When it runs nonstop, the fan consumes more energy, and the air filter needs frequent replacement.
How Much Electricity Does a Ceiling Fan Use? Ceiling fans come in a variety of wattages, but a standard 48-inch model uses about 75 watts per hour on average. This would cost you about $0.01 per hour, or $6 per month if you leave your ceiling fan on 24/7 all month.
When your ducts are blocked or dirty, you get less airflow through vents. This means it takes longer to cool your house, which runs the AC longer, using more overall energy. You're also more likely to walk over to the thermostat and set it a few degrees lower to get the airflow you need to be comfortable.
You can run the fan independently of the AC by switching the fan to “Fan On,” which will keep the blower fan running whether there's a demand for cooling or not. The AC can still come on, but you'll have continuous air circulation when it's not. You can also shut the AC off completely so only the fan runs.
While it is true that the fan alone uses less energy than the AC, leaving it on will almost certainly result in higher utility bills. Running the fan constantly also increases your system's maintenance needs. That's because the more you run the fan, the faster your filter will get clogged.
Using your ceiling fans and AC unit simultaneously can help save you money on your monthly cooling bill. According to the Department of Energy, if you use air conditioning to cool your home, a ceiling fan will allow you to raise the thermostat setting about 4°F with no reduction in comfort.
Answer: You can— and should— run your A/C and ceiling fan together. Doing so can help lower your cooling costs each month, but only if you're using them right.
This means, that in turn, when your setting is turned on auto less electricity is used. When your fan and air conditioner are running all the time, more electricity is produced. All in all, it is better to leave your air conditioner's fan on auto, instead of “On” at all times.
Which Thermostat Setting Is Best: On, Auto, or Circulate? Given the amount of money it costs in increased utility bills and filter purchases to keep your AC fan running constantly, most of the time, you'll want to keep the fan in the “auto” position.
Not necessarily. Typically, running your air conditioner's fan constantly is going to drive up your energy bill slightly. But it also provides a few advantages (and downsides) when it comes to your residence's comfort.
The U.S. Department of Energy (DOE) recommends aiming for an inside temperature of 78 degrees Fahrenheit in summer. In winter, the DOE suggests 68 degrees Fahrenheit as the indoor temperature to aim for, letting that drop lower when you are asleep at night.
The average cost to run a ceiling fan is $0.07 to $0.18 per day or $2 to $5 per month with 8 to 12 hours of daily usage. Pairing a ceiling fan with air conditioning can help lower utility bills by allowing higher thermostat settings while still keeping you cool and comfortable.
Unfortunately, operating the fan continuously during the summer can lead to comfort, health, and property damage risks – mainly because of high indoor humidity.