I remember back when the Detroit Lions used to play at the Pontiac Silverdome (believe it or not, they had winning seasons back then). We had to walk through these revolving doors to get into the pressurized stadium. Maybe one of you knows better (and can share your knowledge in the comments section), but I was told that the stadium was pressurized to keep the roof up.

But in other facilities it’s being shown that revolving doors can improve energy efficiency by keeping the conditioned air where it belongs — inside. Some doors are even being used to help provide some energy (it’s not much, but every little bit counts,