And there's more

"To maintain the differential air pressure, spectators usually enter and leave the seating and concourse areas through revolving doors, since the use of regular doors without an airlock would cause significant loss of air pressure. The double-walled construction allows warmed air to circulate beneath the top of the dome, melting accumulated snow. A sophisticated environmental control center in the lower part of the stadium is manned to monitor weather and make adjustments in air distribution to maintain the roof."

That's the theory anyway.

Posted By: yarmyyarmy, Dec 12, 20:19:25