The 'fan' mode runs the fan continuously, providing constant air circulation. This can be beneficial for even temperature distribution and reducing humidity. The 'auto' mode, on the other hand, only runs the fan when the compressor is cooling the air.
Set the fan speed on high, except on very humid days. When humidity is high, set the fan speed on low for more comfort. The low speed on humid days will cool your home more effectively and remove more moisture from the air because of slower air movement through the cooling equipment.
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.
By using the fan, the Ac need not be on a very cold setting which costs more money. Conclusion: Using Fan along with air conditioner results in the following: Faster cooling – Fan helps to cool your home faster.
"AUTO" is the more energy-efficient option, as it runs the fan only when heating or cooling is actively needed. "ON" keeps the fan running continuously, which can help with air circulation and filtration but may consume more energy.
The ceiling fan direction in summer should be counterclockwise to help create a downdraft, which creates that direct, cooling breeze. Your fan direction in winter needs to be clockwise to create an updraft and circulate warm air around the room.
AUTO is significantly more energy efficient between the two modes since the fan is only running when your AC is going through its cooling cycle. This takes less power, which is more budget-friendly, with some estimates showing you can save as much as $50 per month just by keeping your AC on AUTO.
The fan only turns on when cooling or heating is required. If you are generally as comfortable in one room of your home as the next, you'll want to use the AUTO setting. The AC fan kicks in when needed and stops running when the job is done.
You can expect a more considerable maintenance burden if you run the fan continuously, even if you're running the AC fan without cooling. The filter will clog sooner, and the mechanical parts need more frequent attention to avoid breakdowns.
First, check your filters and coils for dirt and debris that may be impeding airflow. Once you've cleaned the filters and coils, run the air conditioner with just the fan so that the ice accumulation can melt off. If the AC still doesn't blow cold air, it could be that refrigerant levels are too low.
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.
If your unit is low on refrigerant, it won't be able to cool off the warm air, forcing the AC fan to run more often. If you notice warm air pushing through your vents, this may indicate low coolant levels. Most often, refrigerant leaks from an AC coil.
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.
WHAT IS THE BEST MODE FOR AC IN SUMMER? In summer, the best mode for your air conditioner is the "Cool" mode, set to a comfortable temperature around 78°F when you're home. This setting efficiently reduces indoor humidity and maintains a comfortable environment without overworking the AC system.
For your AC system to cool efficiently, the fan needs to be able to move a certain amount of air every minute. For every AC ton, you need between 350 to 400 cubic feet of air per minute (CFM), i.e. a 2.5-ton AC needs 875 to 1,000 CFM, a 5-ton AC needs 1,750 to 2,000 CFM, etc.
Pros of Keeping Your Fan On
First, running fans contribute to even temperature distribution. This reduces the hot spots in your house. Hot spots occur when an area doesn't receive the same temperature-controlled air as other rooms. You'll also enjoy improved air quality in your home.
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.
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. At this point, it should be pretty obvious that AUTO costs less than ON but let's math it out to its logical conclusion.
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.
This is more of a personal question, as different people feel comfortable at different temperatures. Since 72 degrees is generally agreed upon to be an ideal indoor temperature, most people would probably still feel comfortable setting their AC units slightly higher than this, perhaps at around 75.
Setting your thermostat to auto will allow your system to be more energy-efficient since the fan only runs when the system cycles on, not continuously.
Cool mode: Ideal for hot days, this mode reduces the room temperature to your desired setting. Dry mode: Perfect for humid conditions, this mode removes excess moisture from the air without significantly reducing the temperature.
If your AC is running but not cooling, it could be due to a dirty air filter, incorrect thermostat settings, a malfunctioning thermostat, a refrigerant leak, dirty condenser coils, blocked vents or ducts, a faulty compressor, frozen evaporator coils, or electrical issues.
Keeping your thermostat in the AUTO position means less overall energy is being used—and that reduces your utility bills considerably. Not only that, your air filter will last longer than they will if you leave your fan running continuously—in other words, if you leave it in the “on” position.