Is it better to keep AC fan on auto or on?

Author: Palma Beahan II  |  Last update: Wednesday, February 25, 2026

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.

Should my AC fan be on auto or circulate?

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.

Is it better to have your AC on cool or auto?

Conclusion. In conclusion, auto mode in air conditioning not only helps save energy and reduce costs in the long run, but also improves indoor air quality, offers greater control and customisation, and can be more comfortable for the user.

Is it OK to leave AC fan on all the time?

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.

When should I use my AC fan mode?

The fan mode in an air conditioner circulates air without cooling it. It's useful when you want to improve air circulation, reduce humidity, or simply have ventilation without changing the temperature.

Should I set my thermostat fan to on or auto

Is it better to leave AC fan on or auto?

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.

What are the disadvantages of auto mode in AC?

AUTO Setting Disadvantages
  • Hot and Cold Spots. The air distribution throughout the house may be uneven, leaving some areas colder than others. ...
  • Limited Air Circulation. ...
  • Blower Fan Wear and Tear.

Should I keep my fan on when AC is on?

Positioning your fan so that it is near the A/C vent helps distribute cold air faster and more efficiently than the A/C alone could. This helps circulating air for a larger area and cool the room quickly. By using the fan, the Ac need not be on a very cold setting which costs more money.

Is it expensive to run AC fan all day?

Cons to Keeping Fan Continuously Running:

It could cost you hundreds of dollars a year. 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.

Why is AC not blowing cold air?

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.

Which mode is best for AC in summer?

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.

Why is my AC constantly running on auto?

The Short Answer Is: When your air conditioning system keeps running and never seems to shut off, the problem could be linked to a number of malfunctioning components – frozen evaporator coils, a clogged air filter, a bad electrical relay switch that needs to be replaced, the fan blowing constantly, dirty condenser ...

Is it cheaper to keep AC at constant temp?

On the one hand, keeping a constant temperature can be more energy-efficient in some cases because your HVAC system doesn't have to work as hard switching between temperatures. However, this approach can also lead to wasted energy if you're heating or cooling your home when no one can enjoy it.

Should I set my thermostat to auto or cool?

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.

What fan speed is best for cooling AC?

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.

What is the difference between auto and cool on an air conditioner?

Auto mode is similar to cool mode as the AC unit will work to cool the air down. However, unlike cool mode, once the room reaches the set temperature, both the compressor and fan switch off.

Is it better to leave the AC fan on or auto?

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.

Is it more expensive to run AC on an auto or fan?

Bottom line – If you run the fan in AUTO mode, you'll save about $300 per year. If you do want to run the fan continuously, there are a few important things you'll need to consider…

Does auto mode in AC save electricity?

Yes, Auto mode is intended to save energy. The air conditioner can conserve energy and save you money on your energy bills by automatically adjusting the temperature and fan speed based on the ambient conditions and the presence of people in the room.

Should the AC fan be on auto or circulate?

Auto = The fan turns on whenever the heat or AC is on. Fan = The fan is always on. The heat or AC cannot not turn on. Circulate = The fan is always on.

Is it better to have the fan on or auto in the summer?

Choose "AUTO" for energy savings and "ON" if you want constant air circulation or improved air filtration. Temperatures can soar or plummet depending on the time of year.

Is it OK to keep AC on fan mode?

Yes, it is perfectly fine to keep your AC in fan mode. This setting allows the fan to run continuously, circulating air without using the compressor to cool it. This can be particularly useful during mild weather or when you want to save energy by not cooling the air but still need some air movement.

Should I run my AC on auto or on?

AUTO is short for automatic. 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.

Should I keep the fan on with AC?

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.

What happens if I put my AC on auto mode?

Once you select auto mode, the AC unit will use its built-in thermostat to monitor the indoor temperature and adjust the cooling cycle accordingly. The air conditioner will turn on and off as needed, ensuring that your home stays at a consistent temperature without you having to manually adjust the settings.

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