Increasing the fan speed enables more air to pass through the air conditioner. We recommend to set the fan speed at high levels at the start of cooling (or heating), when the room is much warmer (or cooler) than the set temperature. At night, the air conditioner can be set a lower level.
A higher fan speed pushes more air, but it might not feel as cool or regulate humidity as well. On the other hand, a lower fan speed gives the air more time to cool on the evaporator coil, resulting in colder air and better humidity control.
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.
The normal factory setting for blower fans is 400 CFM per ton. This is the setting that is recommended for use in drier climates. However, in more humid climates like Missouri, your fan speed should really be set at 350 CFM. The higher the fan speed is, the more volume of air it will move at one time.
For larger rooms or areas with higher ceilings, a higher RPM (around 400-450) is ideal for effective air circulation. For smaller rooms or spaces requiring less cooling, an RPM between 300-380 is usually sufficient, balancing airflow with energy efficiency and noise levels.
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.
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.
As we stated in a few sections above, it's very important to keep your air conditioner's fan on the auto setting. Some of the reasons behind this choice include: Lowered energy consumption: When your air conditioner's fan is set on auto, it will only run as needed.
Adjusting an air conditioner's fan speed is no easy feat. Although 400 cubic feet per minute (CFM) is the standard fan setting, each AC make and model may require slight variations.
Does fan speed affect electricity consumption? Yes, the fan motor consumes less electricity at a slower speed. Inserted resistance reduces the voltage available to the fan motor.
Start by setting your thermostat higher than normal when you are away, and at 78 degrees when you are home. That is the Department of Energy's recommended setting when you need cooling, but want to save energy.
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.
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.
When trying to find the most reasonable setting for your air conditioner, you have to start somewhere. And, the best spot to do it at is 78 degrees Fahrenheit. According to Energy Star, it's an ideal temperature.
High is usually most effective for cooling during normal warm weather. However, when it's very humid, it's better to keep the fan on low. This cools most effectively because it circulates the humid air slowly and steadily through the air conditioner, allowing it to dehumidify the air more efficiently.
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.
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.
Performance vs Noise
For optimal performance, higher fan speeds are ideal. If your focus is on low noise, however, you can consider setting your fan speeds lower. As a low noise enthusiast, you can even consider running your case fans at 20% until the CPU reaches a temperature of 60°C (as an example).
A good RPM for a ceiling fan is between 200-300 RPM, as it provides a comfortable breeze without generating excessive noise or consuming too much power. However, the ideal RPM may vary depending on factors such as the fan size, room size, and ceiling height.
As mentioned above, the ideal fan speed setting in cooling mode is high fan speed. Later on in the night, we recommend reducing this to medium or low speed. The ideal mode for your air conditioner is to select either heating or cooling mode, not auto mode.
"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.
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.
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.
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.
An air conditioner does dehumidify, but not nearly as well as a dehumidifier. Dehumidifiers are engineered to pull moisture from the air, cool it, and separate it from the air. Depending on the type of dehumidifier you invest in, the excess water may drip into a tray which needs to be occasionally emptied.