Running the Fan Continuously vs. Anything that runs 24/7 will deteriorate faster than something that has rest periods. Even the ongoing stops and starts when you set the fan to auto are less damaging than what happens with months or years of constant use.
They should not be left on all the time. Some of the more advanced thermostats might use the fan to better circulate the air post-AC or heat running or pre-cool the home a little by running the fan. But in normal operation, it only runs with the furnace or AC does.
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.
They should not be left on all the time. Some of the more advanced thermostats might use the fan to better circulate the air post-AC or heat running or pre-cool the home a little by running the fan. But in normal operation, it only runs with the furnace or AC does.
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.
Compared to the ON setting, the AUTO setting gives you benefits such as: Lower energy consumption. In AUTO mode, the blower fan only runs when necessary, which cuts down your AC system's energy usage. Reduced wear and tear on AC components.
Cons of Keeping Your Fan On
A running fan uses lots of electricity to cycle. Plus, you'll decrease your AC's efficiency during the hot summer months. Your vents could blow hot air into your home, increasing your unit's regulation cycling. This will also greatly increase your energy bill during hot or cold seasons.
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.
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.
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 fan's housing will get warm after prolonged use due to the fan's motor generating heat when converting electricity into movement. This heat is why many people think it is unsafe to leave fans running; however, it is normal and will dissipate from the fan's housing and not exceed a safe limit.
Run the Fan When You're Not Home
You don't want to waste energy when you're out of the house. Instead of leaving your HVAC system on while you're away, you can run the fan to keep the house from getting stuffy. A programmable or a smart thermostat allows you to schedule your fan to run for a set number of hours.
Leaving your AC fan set to ON allows the moisture in your home to accumulate and reach mold-growing levels of humidity. To ensure that you and your family stay cool and healthy this summer, keep your AC thermostat fan setting to AUTO.
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.
In normal operation, no, the radiator fan doesn't run all the time. The fan is hooked to a sensor that measures the coolant temperature in the radiator, and when the temperature gets a little on the high side, the sensor will (basically) send a signal that turns the fan on.
An undersized air conditioning system most commonly manifests as an air conditioner that never stops running. When this occurs, cooling coil pressure will start to drop before freezing over, which could damage your AC's compressor.
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.
You should run the fan on your air conditioner during cooler parts of the day or when the temperature is not too high. It's also useful when you want to circulate already-cooled air or when the room feels stuffy. Using the fan mode can help save energy as it consumes less power than the cooling mode.
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.
A balanced solution is to use both together, with the AC set at a moderate temperature and a fan to help circulate cool air, reducing energy usage while keeping the room comfortable for restful sleep.
The breeze evaporates moisture from your skin which makes you feel warmer. When a ceiling fan is used, you can raise the thermostat setting by up to 4 degrees Fahrenheit without any reduction in comfort. Therefore, your AC unit gets a break and lessens the odds of requiring air conditioning repair service.
When indoor air temperatures are hotter than about 95 °F: Fan use may cause your body to gain heat instead of lose it. On very hot, humid days, sweat evaporates off the skin slower than normal, and fans make it even more difficult for the body to lose heat by sweating.
A ceiling fan used along with the air conditioner can make the room feel comfortable faster and also help reduce the overall electricity bill. Let us explain how. The normal temperature of the human body is around 37 degrees Celsius.
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.