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.
For example, a standard central air conditioner, like the one you probably have in your house, consumes between 3,000 and 3,500 watts of electricity per hour. That same AC when only the fan is running consumes 500 watts of electricity per hour. That's an enormous difference!
Running a home air conditioner 24/7/365 can put a strain on the unit and potentially lead to increased wear and tear. This constant operation may result in higher energy bills and could shorten the lifespan of the equipment.
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.
A central air fan uses about 600w while running. Running it 24/7 will use about $43 of electricity per month if your rate is $0.10 (pretty average). So yes, it does cost a lot to run it constantly.
When the California summer heat rolls in, pairing your AC with a ceiling fan is your best defense. By correctly setting the fan's direction, adjusting the thermostat, and a few other simple strategies, you can keep your home cool without driving up your energy bill.
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.
Energy Conservation: The fan mode is more energy-efficient than running the AC in cooling mode, helping to save on electricity costs. It circulates air without changing the temperature or humidity levels, using less power than the cooling mode.
The AC uses less energy in fan mode than when cooling. But running the fan all the time can increase the amount of maintenance your HVAC system might need. That's because the filter can clog up sooner and mechanical wear and tear can accelerate.
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.
It only makes you FEEL cooler because it's moving air over your skin, carrying the heat away from your body. This is the wind chill factor you hear on the Weather Channel so often. So it's doing nothing to lower the temperature in your home, meaning your A/C will run just as long whether the fan is on or not.
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.
Your blower motor circulates air through the furnace and can provide uniform temperatures. Many people leave their HVAC fan on all day, while others opt for two to three cycles per hour, ranging from ten to 25 minutes, depending on how close to heating or cooling temperatures they are.
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.
Heating and cooling: 45-50%
The largest electricity consumer in the average household is your heating and cooling appliance. By a long shot. Central air conditioners and heaters use tons of energy in order to keep your home set to the right temperature.
Setting the fan speed too low will usually cause the evaporator coil to freeze. If the fan speed is too high, it can cause the AC condenser to short-cycle or turn on and off constantly. This puts a huge amount of stress on the unit and also results in greatly increased energy costs.
A typical AC fan motor uses about 500 watts when it's running. Therefore, if you run the fan continuously for a 30-day month (720 hours), you would use 360,000 watt hours (720 x 500) or 360 kilowatt hours (kWh). Therefore, the fan uses about 360 kWh per month in the ON mode.
A ceiling fan is made up of different parts and pieces, and they will wear out over time. Sure, your ceiling fan can run throughout the day and night without issue, but running it for several days or months on end may not be the smartest choice and will reduce the overall lifetime of your fan.
Consequences of Running Your Air Conditioner 24 Hours a Day
Wasted energy: Running the AC to cool your home beyond your comfort level wastes energy and contributes to an increased carbon footprint. This is bad news for the environment and your energy bills.
You can choose to run the fan continuously or only when the AC is on. This setting helps circulate air in your home, but it won't produce any new cold air.
Air conditioning can run you hundreds of dollars every month to cool your home, while running a fan in that same time frame costs about as much as a large cup of coffee. Cool air can circulate around your home evenly, without racking up a hefty bill.
The fan will constantly blow air into your room if you have the thermostat turned “ON.” If it is on “AUTO,” it will only turn the fan on when heated air needs distribution. So yes, running HVAC continuously throughout the day and night is perfectly safe!
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 means you'll be using less energy and saving money on your electric bill by using the AUTO setting.
Understanding the Fan Mode
What does the fan setting on an air conditioner do? It activates the unit's fan to circulate the existing air in the room without engaging the cooling mechanism. This way, it helps in creating a fresh ambiance without significantly altering the room's temperature or humidity levels.
"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.