I’ve wondered several times over the years if there is really any tangible proof that revolving doors do, in fact, save energy, and after discussing this topic on Friday with a coworker I decided to finally research the topic. I’ll admit, I was a little doubtful that the amount of energy a revolving door saved, if any, would be large enough to quantify. Doing a quick internet search, though, I very quickly found a study done by MIT on this exact subject which is summarized here. The study showed that 8x as much air is exchanged when using a swinging door versus the use of a revolving door. In fact, how much heat is transferred when using a swinging door is pretty amazing. The heat transfer is approximately 267 BTUs, which is roughly equivalent to:

• 1.3 hours of an incandescent lamp
• 4.3 hours of a compact fluorescent lamp
• Driving a car 306 feet
• Half a mile jog

This study indicated that if everyone used the revolving doors at one MIT building, the college could save $7500 in natural gas alone each year! Of course, on temperate Spring and Fall days the energy savings from using a revolving door may be minimal, but this study is certainly en0ugh to ensure that I will be very conscious of always using the revolving door from now on!