There are three vents almost directly above my desk. One is for a building-wide system, one is for a system for this floor only. No one seems to know what the other one is. The cold, dry air blasts down at me all day long and is so bad that my left arm and hand, which get the blast full-on, are considerably colder than my right. Sometimes if I'm using my mouse for a long time my left hand even seizes up a bit from the cold. I'm forever getting up and turning off the one aircon vent that we can control. Why it's deemed necessary to have it on at all in the depths of winter is totally beyond me.