Buildings are the largest consumer of energy in the United States, with residential and commercial properties together accounting for about 40 percent of the country's energy use. Most of that, in turn, comes from all the effort it takes to heat and cool these places with a kind of ham-handed precision.
"We heat our homes during the day when nobody is there, and we heat our offices during the night when nobody is there," says Carlo Ratti, the director of MIT's Senseable City Lab. Even when people are there, we heat whole apartments just because someone is curled on a couch in the living room. And we cool whole office buildings to accommodate a couple of people in a conference room.
Perhaps you see where Ratti is heading with this: "Can we use technology," he asks, "in order to put the energy where the people are?"
This idea is not so far-fetched. A smart thermostat, the Nest, has already been designed (by former Apple hands) to know when you're not home, when you're coming back, and how warm you'd like it to be. Extrapolate that kind of personalized efficiency even farther into the future, Ratti says, and you get something that looks more like this:
Those are infrared beams of warmth targeting individual people as they move through space.
"In the old days, we could only heat up whole buildings and have everything the same temperature," Ratti says. "In the future, you can imagine a system where you have a bubble per person of individual climate control."
If we could heat and cool people this way (the goal, after all, is to heat and cool people, not places), Ratti's lab has estimated that we could save more than 50 percent of the energy currently devoted to the task.
Lest this look too much like science fiction, MIT has actually tested the idea on the monumental steps to the university's main entrance, the scene rendered in the sketch above. In March, the lab installed three of these concentrated infrared energy beams, which then tracked people walking below with the help of cameras and the kind of Kinect sensors found in an Xbox.
By testing the idea outdoors – in Boston, in March – the lab has proven that this at least could work even in open-air environments. The technology itself is not that different from heating lamps you may have used in an outdoor cafe. Here, however, the concept applies equally to both indoor and outdoor spaces, blurring the architectural boundary between the two, as the researchers put it.
"What we’re trying to do with the lab is explore different futures," Ratti says. If you reverse-engineer the future – picture it as a place where hyper-localized climate control is actually commonplace – then how would you get there? This first installation is just a proof of concept in an ongoing "Local Warming" project by the lab. As far as exactly what this might look like in your office space or apartment, that's an open question.
It will also be trickier to figure out how to cool people. But that task doesn't seem too far beyond what science can figure out.