On average 8x as much air is exchanged when a swing door is opened as opposed to a revolving door. That’s 8x as much new air that needs to be heated or cooled and that’s why using the revolving door is a great way to reduce energy requirements on campus.
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You’ve probably seen the signs around campus saying “Help MIT save energy. Please use the revolving door.” But does it really make any difference? Absolutely. Our estimates show that if everyone used the revolving doors at E25 alone, MIT would save almost $7500 in natural gas amounting to nearly 15 tons of CO2. And that’s just from two of the 29 revolving doors on campus!