I have a weird condition here.
If average weather temperature outside is 30 (86 Fahrenheit) in whole day (8am - midnight), my room will be quite hot, even I set my aircon in fan 2 - 18 degree.
While, if the average temperature is around 26 (79F), my room will be cold enough in fan 1 - 24, or even 25 (77F), degree.
What could be wrong in my aircon? Usually I turn on the aircon after go back from work - going to go to work next day.