I recently installed 4 temp loggers in a business building - used 9-5 M-F. Interesting results...
goo.gl/HH9Q4f
The red and green lines show daily max and min. You can see on the weekend that in general the rooms get a bit warm - 1 room up to 30C when its max35 outside. The warm room also gets warm later as its at the W end of building - no verandah over this wall.
The blue line is in the roof space. On the weekend it rises quite high - over external max as you might expect, but on business days it gets limited when the AC comes on - a good demonstration of leakage (through ducting) of the cooling form AC. I don't think there are any ducts disconnected but will be checking. So the AC is cooling the ceiling ! and hot roof space is warming AC duct air.
One room AC was left on all night on Wed - for some reason it was holding at 24C during the day then dropped to 21C - maybe staff turned T down rather than off ? Interesteing to see that generally they are using a set temp of 24C.
Building doesn't cool down much at night - probably because they seal it up for security. With some forced, overnight ventilation it might be possible to get it cool enough that they don't need AC so often.