Am not 100% sure on this one but I always took 'centrally controlled' to mean they put it on as and when, and selected temperature

How cold is cold? Quite frankly sleeping with an a/c unit on its lowest setting and highest fan speed is not good for you. I live inland from Alicante where the night time temperature is about 28C at the moment. My bedroom a/c unit runs on low speed at 23C and switches off and on to adjust the temperature during the night. The room is cool and comfortable which is what you need for a good night's sleep

Centrally controlled means they decide when the air conditioning is switched on, but you control the temperature of the room via the air conditioning unit.

A friend of mine stayed there last week, he said the weather was very hot. But the hotel wouldnt turn the air cond on in the rooms because they dont usually turn it on till June 21st.