Sleep mode (moon)
A night setting that lets the room temperature drift a little — warmer when cooling, cooler when heating — over the first hours of the night.
What pressing it does
Press SLEEP after choosing cool or heat. Airwell raises the setting by 1 °C after about an hour in cooling (lowers it by 1 °C in heating) and again an hour later; Gree’s Sleep 1 adds 2 °F after one hour and 4 °F after two. Fujitsu’s SLEEP timer does the same and then switches the unit off at the set time.
What it does not do
It does not work in every mode — Midea says it is not available in Fan or Dry mode — and it is not the same as an off timer: of the makes cited, only Fujitsu’s SLEEP timer and Samsung’s good’sleep (in Cool) switch the unit off when the time is up.
Makes differ, check your unit’s manual: the same drawing can mean different things on different brands, and only your model’s manual says exactly what a button does and which modes it works in.
- What it looks like
- A crescent moon, sometimes with a sleeping face or small stars.
- Names makers use
- SLEEP (Midea, Airwell, Gree); SLEEP timer (Fujitsu); good’sleep (Samsung)
Where makers differ
The size and timing of the drift differ by make; Samsung’s good’sleep defaults to 8 hours and adds a “Wake up” phase. Mitsubishi Electric’s NIGHT MODE is a different thing: it dims the lamp and quiets the outdoor unit.
Other symbols with the same shapes
Sources
No single published standard defines air-conditioner remote icons, so this meaning is taken from 5 makers’ own manuals, each fetched and read on the date shown:
- Airwell: Airwell — RC08W remote control manual (PDF) — “What does the SLEEP mode mean?” — cools or heats to the set temperature, then after about 1 hour the setting is raised by 1 °C (cooling, dehumidifying) or lowered by 1 °C (heating), then again after another hour. Checked 2026-09-26.
- Midea: Midea — Remote controller owner’s manual, RG51A(2)/E and RG51B(2)/E (PDF) — “The SLEEP function is used to decrease energy use while you sleep … The sleep function is not available in Fan or Dry mode.” Moon-face icon: “Displayed when SLEEP feature is activated.” Checked 2026-09-26.
- Fujitsu General: Fujitsu General — Operating manual, wall-mounted 18/24RLB and 30/36RLXB (US, PDF) — “SLEEP timer … controls the temperature setting automatically in accordance with the set time … The air conditioner completely turns off after the set time has elapsed.” Checked 2026-09-26.
- Gree: Gree Comfort — Vireo GEN3 indoor unit owner’s manual (PDF) — Sleep 1, 2 and 3; “Sleep mode 1; in COOL mode: after running one hour, the temperature will increase 2°F, in two hours it will increase by 4°F.” Checked 2026-09-26.
- Samsung: Samsung — Wind-Free 2.0 air conditioner user manual, AR**TSFA*** (PDF on Samsung HVAC’s document store) — good’sleep in Cool or Heat mode; default 8 hours; Wake up begins 1 hour before the set time if over 5 hours; the unit stops when the time expires in Cool mode. Checked 2026-09-26.
Written in our own words; quotations are the makers’ wording.