Greening MIT

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Other efforts to change behavior are under way. Wesolowski, along with other students, also studied the use of revolving doors in the MIT Medical building (E25). "On average eight times as much air is exchanged when a swing door is opened as opposed to a revolving door. That's eight times as much air that needs to be heated or cooled," the students wrote. They concluded that if everyone used the revolving doors in E25, MIT would save almost $7,500 in natural gas each year--enough to heat five houses--and eliminate nearly 15 tons of carbon dioxide emissions. Their study also found that many people avoid the revolving doors because they're hard to push, a problem the facilities department has since addressed by servicing them and making sure they work properly. And Wesolowski found that more people use these doors if signs explain why it's a good idea and thank them for doing so. Permanent versions of those signs are now installed across campus.

But getting people to change their behavior isn't enough. The $24,000 per year saved by closing the fume hoods, for example, was less than 7 percent of what Amanti had expected; according to the data Swager collected, the hoods weren't being left open as wide as Amanti had estimated, so far less energy was being wasted. Another problem with behavioral changes is that they don't always last. A recent study of energy-efficient buildings by the National Renewable Energy Laboratory in Golden, CO, showed that bad habits can return quickly: people who at first responded to prompts to save energy in a new building were ignoring them after a year. At the least, maintaining savings from behavior requires continuing education, Lanou says--especially at a place like MIT, where new people are constantly arriving.

Where people fail, however, technology can sometimes help. And even disappointing results can be instructive if they yield enough data. Such detailed information has been missing from many efforts to improve energy efficiency because making the necessary measurements can be costly; but MIT has decided to focus on carefully quantifying changes in energy use to determine what approaches work, and how well.

Steam Traps and Data Floods

Most of MIT's projects for cutting energy use won't win any prizes for innovation. The lights in the duPont squash courts used to burn 24 hours a day. No more: occupancy sensors now shut them off when no one is playing. Likewise, installing occupancy sensors in the ice rink and swapping old high-intensity discharge lamps for fluorescent lamps has cut electricity consumption for lighting in half, while making the rink twice as bright. Still, these and similar changes to be made across campus are expected to pay for themselves in a little over two years.

The facilities department is rigorously tracking results from such projects to verify which ones pay off. To test one energy-saving measure, they replaced faulty steam traps in one of the two nearly identical East Campus dorm buildings. Properly functioning steam traps keep the steam in radiators until it condenses and gives off its heat; when they don't work, steam passes through continuously. Not only does this make the radiator too hot, it also wastes much of the energy in the steam. Replacing the traps campuswide saved about $800,000 in one year, more than covering the $765,000 bill for the repairs and the sensors installed to monitor the system. Although it cost more to install the East Campus sensors than it did to fix the two dorms' steam traps, Cooper considers the money well spent since it allowed MIT to quantify the savings.