Fan mode runs only the indoor fan of your air conditioner. The compressor stays off, so the air is moved but not cooled and the room temperature does not drop. Use it to circulate air when the temperature is already comfortable, and switch to Cool when you need the room colder.
Fan mode on an AC runs only the indoor fan. The compressor stays off, so the air is moved but not cooled, and the room temperature does not drop. Use it to circulate air when the temperature is already comfortable, and switch to Cool when you need the room colder.
How fan mode works
In Cool mode, the compressor does the cooling and cycles on and off to hold your set temperature, while the fan moves the air. Fan mode keeps the fan and leaves the compressor off.
GE puts it in one line in the owner's manual for its ASH and ASW window models: the Fan setting provides air circulation and filtering without cooling. Because there is no cooling, GE adds, the unit does not display a temperature setting in Fan mode.
Other makers say the same in their own words:
- LG: its LT series owner's manual calls Fan "fan-only operation", next to Cool and Energy Saver on the Mode button.
- Midea: the window inverter manual says to use Fan Only when cooling is not desired, such as for room air circulation or to exhaust stale air on models with a vent. In this mode the display shows the actual room temperature, and you can pick any fan speed.
- MrCool: the mini split remote manual says you cannot set or adjust the temperature in Fan mode, so none shows on the remote screen.
- Daikin: the FTX30NVJU and FTX36NVJU manual says the temperature setting cannot be changed in Dry or Fan operation.
So why does fan mode feel cooler? ENERGY STAR explains it for ceiling fans on its fan usage tips page: fans cool people, not rooms, because the moving air creates a wind-chill effect. The thermometer in the room stays where it was.
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Fan mode is not the same as fan speed
Every AC lets you set the fan speed in Cool mode too. GE lists High, Med and Low fan for cooling, and Daikin offers Auto, a quiet setting and airflow rates 1 to 5. In those cases the compressor still runs, so you are cooling. Only Fan mode on the Mode button turns cooling off. If what you want is quieter cooling rather than no cooling, GE suggests Cool mode with the Low fan and a middle set temperature. Auto fan speed is a separate setting again; our page on auto mode on an AC covers both.
When to use fan mode and when not to
Fan mode is useful when the temperature is fine but the air feels still:
- The evening has cooled off and you want air moving without running the compressor.
- You want to push stale air out through a window unit's vent (Midea says to open the vent for this).
- You want air moving through the unit's filter. GE describes Fan as circulation and filtering.
Do not use it to fix a hot room. With the compressor off, the room will not get colder. If Cool mode is not cooling either, the problem is the AC, not the setting; start with our steps to reset your air conditioner.
Do not count on it for a sticky room either. For humidity, dry mode is the setting built for it.
One habit protects the compressor. GE says that after switching from a cool setting to Off or to Fan, you should wait at least 3 minutes before switching back to Cool. Midea's window units build in an automatic 3 minute delay before the compressor restarts, and the fan keeps running during that time.
Fan "On" vs "Auto" on a central thermostat
Central air systems do not have a fan mode on a remote. They have a fan switch on the thermostat, usually marked Auto and On, and On works much like fan mode: the blower runs whether or not the system is cooling.
- Auto: Carrier's AC thermostat guide says the fan only runs when the compressor is actively cooling the air.
- On: the fan runs continuously, which Carrier says consumes extra electricity.
Humidity is the other cost. Lennox, on its page about an AC that cools but leaves the air humid, says setting the fan to On instead of Auto can blow humid air back into the room even when the cooling cycle is not running.
The DOE's Energy Saver guide gives the plain rule: set the thermostat fan switch to Auto unless an indoor air quality professional has set up your system to run continuously for health reasons.
How to turn on fan mode
| Brand | Button or symbol | Where it is documented |
|---|---|---|
| GE (ASH, ASW) | Mode pad to Fan, then Fan pad for High (F3), Med (F2) or Low (F1); knob models use Low Fan or High Fan | GE owner's manual 49-7424, pages 4 to 6 |
| LG (LT series) | Mode button to Fan | LG LT series owner's manual, controls page |
| Midea (MAW window inverter) | Mode button, last in the order Auto, Cool, Dry, Heat, Fan | Midea user manual, pages 22 and 23 |
| MrCool | Mode button to Fan, then set the fan speed | MrCool remote user manual, page 6 |
| Daikin (FTX NVJU) | Mode selector to Fan on the ARC466A37 remote | Daikin operation manual, pages 8 and 11 |
| Central thermostat | Fan switch or menu set to On | Carrier AC thermostat guide |
Does fan mode save energy?
With the compressor off, fan mode draws only what the fan motor uses, but that is still electricity. Carrier makes the point for central systems: a fan set to On consumes extra electricity. A fan left running all day is a cost, not a saving, if no one needs the air moving.
ENERGY STAR gives the same advice for ceiling fans: if the room is unoccupied, turn the fan off. If you want to run a fan to feel cooler at a higher thermostat setting, the DOE says a ceiling fan lets you raise the thermostat about 4°F without any loss in comfort. To see what a fan or AC costs to run at your electricity rate, try our cost to run calculator, and for the rest of the remote, see our guide to AC modes.
Frequently asked questions
Does fan mode on an AC cool the room?
No. GE's manual describes the fan setting as air circulation and filtering without cooling, and Midea says to use Fan Only when cooling is not desired. Moving air can make you feel cooler through a wind-chill effect, which ENERGY STAR explains for ceiling fans, but the room temperature stays the same.
Is fan mode cheaper to run than cool mode?
It runs without the compressor, so it draws only what the fan uses, but it is not free. Carrier says a central fan set to On uses extra electricity compared with Auto, and ENERGY STAR advises turning fans off in rooms no one is using. For a cost estimate, use the fan or AC wattage and your electricity rate.
Should my thermostat fan be set to On or Auto in summer?
Auto for most homes. The DOE says to keep the fan switch on Auto unless an indoor air quality professional set your system to run continuously for health reasons. Lennox notes that On can blow humid air back into the room between cooling cycles, and Carrier says it uses extra electricity.
Why does my AC show the room temperature in fan mode?
Because there is no set temperature to show. Midea's window units display the actual room temperature in Fan Only. GE says no temperature setting is displayed, and MrCool says the temperature cannot be set in Fan mode. When you switch back to Cool, the display returns to your set temperature.
Founder of Home Caprice. Ben started the site to simplify HVAC after dealing with the heating and cooling in his first apartment.