How does the ECO function work and when can I use it?

The ECO function is only available in COOL (Cooling) mode. When activated and the set temperature is below 24°C/75°F, the remote controller automatically adjusts the temperature to 24°C/75°F and sets the fan speed to Auto to save energy. If the set temperature is already above 24°C/75°F, pressing ECO will only change the fan speed to Auto while leaving the temperature unchanged. (Page 12 / Page 29)