Set Cool Temperature

I have similar question. I also have a  Purifier Hot + Cool Formaldehyde (White/Gold).

In a room size of 4 meter by 3 meter, with windows and doors closed, at night , the room temperature is 25 Celsius. I set the target temperature to 18 celcius, and fan speed at just 1 (because I wanted the fan to be as quiet as possible while I’m sleeping). 

I set 18 celcius target temperature by pressing the red minus thermostat control button to 18 celcius and then press the blue dot cooling mode button.

After 6 hours, at night, from 1am to 7am, the room temperature is 23 celcius. Is that the correct outcome? I was hoping that the room temperature would be 18 celcius after maybe an hour or at least by 6 hours. What is the correct expectation for the cool feature? What does it do? If I want the room to be 18 celcius on a hot day, how do I configure the unit to cool the room to 18 celcius (if the cool feature is designed to do that). 

(Edited by moderator – Moved to new Topic and amended title)