He's probably exaggerating, but smoke evacuation fans with very high power are not unusual. I was at the LA convention center once when some bozo apparently tossed a cigarette into a dumpster and set it on fire. This wasn't a big deal, because the place is concrete and fully sprinklered, but it produced a lot of smoke. The smoke evacuation fans high above the lobby were started, and wound up to aircraft propeller noise level as they sucked the smoke out of the building. Worked fine; SIGGRAPH went on as scheduled.