There is warmth in places...

Apparently, the hall does have air conditioning that is on, and it is set to heat.  ChaosCentral estimates the heating capacity is about 4 candle power for approximately 2000m3, giving a heat-to-person ratio of about nothing with an estimated error of 100%

However, as the photos show, the practice hall *does* have working heaters, which is why the room is so popular :)