Our esteemed editor Lloyd has, until recently, been an ardent critic of "smart thermostats" and other gadgetry. From his praise for the dumb home or trashing Honeywell's smart-phone enabled thermostat, he's got a pretty solid argument.
At the risk of misrepresenting my boss, here's the gist:
a) Why spend money on expensive thermostats when air sealing, insulation and behavior change deliver more bang for your buck?
b) Smart thermostats encourage you to constantly tinker with your temperature settings. In a well-designed house, that may waste more energy than it saves.
Feeling hot? Many humans will crank up the AC. A smart thermostat can analyze your options and turn a fan on instead. Come home and the house is cold? Too many of us will crank the thermostat above and beyond the temperature you want it to be at—in the misguided belief that it will warm up faster. By providing the time it will take to reach your desired temperature—and by rewarding "good" behavior with a little leaf symbol, Nest provides users with subtle incentives to make better choices.
The other side of Lloyd's argument—that money would be better spent on insulation or air sealing—makes perfect sense, at least it would if we lived in a perfectly rational world. It reminds me, however, of a classic split you see in debt counseling. On the one hand, we are told we should pay down our credit cards with the highest interest rates first. That's solid advice for people who are well motivated and have a plan they are going to stick to. Some financial experts, however, also counsel a different option: namely pay off the smallest balance first so you feel the rewards of achieving the low hanging fruit.
Smart thermostats may serve a similar purpose.
We all know we should seal drafts, install insulation and put up a washing line—all too often, however, we don't. By providing an attractive, fashionable (and yes, expensive) first step on the path to energy efficiency, smart thermostats may act as a gateway drug. Just as solar panels often encourage behavior change, smart thermostats can engage homeowners in their home's performance and perhaps even offer specific suggestions for making things better. (Yeah, I am not sure how I feel about a google ad for insulation appearing on my living room wall either - but you get my drift.)
So yes, it's kind of crazy that people will pay hundreds of dollars for a thermostat before they'll weatherstrip their doors, but it doesn't take much to tell you that we live in a crazy world. So long as smart thermostat designers are focused on helping homeowners save more energy—rather than allowing them to obsessively tweak their surroundings—I firmly believe they are a step in the right direction.