What Is Eco Mode on an AC? How Each Brand Defines It

Eco mode on an AC is an energy saving setting, but it does not do the same thing on every brand. On LG, GE, Frigidaire and Midea window units it switches the fan off when the compressor stops, so both cycle together. On MrCool and Senville mini splits it raises the set temperature to 75°F, and on Daikin it caps the unit's maximum power. Use it to hold a comfortable room, not to cool a hot one fast.

How eco mode works: three different definitions

The button may say Eco, Econ, Econo or Energy Saver. We read the manuals and support pages of six makers, and they fall into three groups. Check which group your unit is in before you judge whether eco mode works.

1. The fan cycles with the compressor (window units)

In normal Cool mode on a window unit, the fan keeps running after the room reaches your temperature, and only the compressor stops. Eco mode stops the fan as well, then wakes it now and then to check the room.

• LG: the owner's manual for LG's LT series says that in Energy Saver the fan stops when the compressor stops cooling, then turns on about every 3 minutes to check the room air. In Cool, the fan runs continually.
• GE: the owner's manual for GE's ASH and ASW models says that with Energy Saver on, the fan and compressor cycle on and off together. GE adds that this gives wider swings in room temperature and humidity and is normally used when the room is unoccupied.
• Frigidaire: Frigidaire's Econ mode support article says the unit turns off at the set temperature and the fan runs for 20 seconds every 10 minutes to check the room. Its features and settings page gives a different pattern for ECO mode: the fan runs 3 minutes after the compressor stops, then 2 minutes every 10 minutes. The timing likely depends on the model, so check your use and care manual.
• Midea window units: Midea's window inverter manual describes the same 3 minutes, then 2 minutes at 10 minute intervals, until the room rises above the set temperature and cooling starts again.

2. The set temperature goes up (MrCool and Senville)

MrCool and Senville mini splits treat Eco as a set point change. MrCool's remote control user manual says that in Cool mode, pressing Eco raises the temperature to 75°F and sets the fan to Auto, but only if you had it set below 75°F. If you were already at 75°F or above, only the fan changes to Auto.

Changing the mode or setting the temperature below 75°F cancels it. MrCool warns that the setting may cool less than you want, and says to press Eco again to turn it off if the room feels warm. Senville's remote controller manual describes the same 24°C (75°F) rule.

The same MrCool button also has a GEAR setting. Pressing it again steps to GEAR 75% and GEAR 50%, which limit the unit to up to 75% or 50% of its electrical energy consumption. Both work in Cool mode only.

3. The compressor's power is capped (Daikin)

Daikin's version is called Econo. The operation manual for its FTX30NVJU and FTX36NVJU says Econo enables efficient operation by limiting the maximum power consumption. Daikin pitches it as a way to stop the circuit breaker tripping when the AC shares a circuit with other appliances.

Daikin also says that if power use is already low, switching to Econo will not reduce it. In other words, Econo only makes a difference when the unit would otherwise draw more. Our guide to inverter air conditioners covers how a variable-speed compressor changes its output.

When to use eco mode and when not to

Eco mode suits steady conditions: a room that is already near your temperature, mild weather, or a room no one is in. GE says outright that its Energy Saver is normally used when the room is unoccupied.

Skip it when you need fast cooling. MrCool warns that its Eco setting may not cool enough, and a power cap by design limits how much the unit can draw.

Be careful with fan-cycling eco modes in humid weather. GE notes wider variations in humidity when the fan and compressor cycle together. If the room feels clammy, normal Cool or dry mode is the better choice.

The fan cycling can also look like a fault. A window unit that goes quiet, then blows for a minute or two, may simply be in eco mode. If it shuts off and restarts in a pattern that does not match your manual, try our steps to reset your air conditioner.

How to turn on eco mode

One quirk: some window units start in eco mode. Frigidaire says EPA rules require its ENERGY STAR room air conditioners to be factory set to Energy Saver mode, and that turning the unit off in Cool and back on returns it to Energy Saver. You can switch out with the Mode button.

Does eco mode save energy?

Each maker presents it as an energy saver. The fan-cycling versions stop the fan between cooling cycles, the MrCool and Senville version cools to a higher temperature, and Daikin's caps the power draw. Frigidaire recommends leaving Energy Saver on.

None of the manuals or support pages we opened gives a percentage, so we do not give one either. Your saving depends on the unit, the room and how many hours it runs. Our cost to run calculator shows what your AC costs per hour and per month at your state's electricity rate.

The setting that moves the bill most is still the temperature. Daikin recommends 78 to 82°F for cooling, and the DOE's Energy Saver guide says to set your thermostat as high as is comfortable when you are home and awake. For the other modes on your remote, see our guide to AC modes.