how an aircon works

someone please tell me how an aircon works! i did a search and i found this: http://en.wikipedia.org/wiki/Air_conditioning & http://www.oreganair.com.au/howair.htm.. i hope the technicians in my lab would start putting their professionalism to use and fix that faulty aircon that is causing everyone more stress and discomfort on top of the "hard to follow" lab rules and regulations.. please fix that aircon!!!