Cool (snowflake icon)
Standard air conditioning. The unit removes heat from the room to hit your set temperature, and the inverter throttles down to hold it steadily. This is your summer default. Pair it with a sensible setpoint - see best temperature settings.
Heat (sun icon)
Heat-pump heating - the same system running in reverse to warm the room efficiently. Your winter default. In cold climates, note there may be a brief pause now and then for a defrost cycle (normal), and cold-climate models hold output better in deep cold - see cold-weather performance.
Dry (water drop icon)
Dehumidify mode. The unit runs gently to pull moisture out of the air without aggressively cooling the room - ideal for muggy, not-that-hot days (spring, rainy stretches) when you want to kill the clamminess but don't need a big temperature drop. It's not a replacement for a dedicated dehumidifier in a basement, but for everyday humidity it's handy. More on this in do mini splits dehumidify.
Fan (fan icon)
Just moves air - no heating, no cooling, no dehumidifying. Useful for circulating air on a mild day, or to keep air moving without changing the temperature. It uses very little power since the compressor isn't running.
Auto (often "A" or a swap icon)
The unit picks heating or cooling automatically to maintain your target temperature - handy in shoulder seasons when days are warm and nights are cool and you don't want to switch modes manually. The tradeoff is less direct control; some people prefer to choose Cool or Heat themselves so the unit doesn't flip modes unexpectedly.
Which mode should you use?
- Hot day: Cool.
- Cold day: Heat.
- Muggy but mild: Dry.
- Just want air moving: Fan.
- Warm days, cool nights, don't want to fuss: Auto.
That's it - most of the year you'll live in Cool or Heat, and reach for Dry, Fan, or Auto when the situation calls for it. New to how the system does all this? See how mini splits work.
FAQ
What does dry mode do on a mini split? It dehumidifies - running gently to remove moisture without strongly cooling the room. Best for muggy, mild days when you want to cut humidity without a big temperature drop.
Should I use auto mode on my mini split? Auto is convenient in shoulder seasons, letting the unit switch between heating and cooling to hold a target. Many people prefer manually selecting Cool or Heat for more predictable control.
What's the difference between fan and cool mode? Fan only circulates air with no temperature change and uses little power; Cool actively removes heat to lower the room temperature.
Which mini split mode is most efficient? Whichever matches your actual need - Fan uses the least power (no compressor), Dry is efficient for humidity, and Cool/Heat run efficiently at steady low output. Using the right mode for the conditions is what saves energy.