Whether you believe or not, the revolving door could save much more energy compared with sliding door or swing door. 

In the year 2006, some students at MIT conducted an analysis of door use in one building, where they found just 23 percent of visitors used the revolving doors. According to MIT's calculations, the swinging door allowed as much as eight times more air to pass through the building than the revolving door. According to the April 2009 MIT Tech Talk publication, Research from MIT students indicates that if everyone were to use the revolving doors in the Building, it could save almost USD 7,500 in natural gas a year, which could be enough to heat at least 5 houses over the same timeframe, and it also adds up to nearly 15 tons of CO .

With the same situation, after the calculation, the sliding door allowed as much as about 10 times more air to pass through the building than the revolving door.  The chart below could make us know the energy saving better.

If possible, kindly suggest to install the revolving door, it could not only save us more money finally, but also do some positive contributions to the environment protection.