GreenSpace: Building a better thermostat

Harvey Sachs has worked on energy efficiency in buildings for three decades.

His wife is a systems engineer with an advanced degree.

Neither has mastered their home's programmable thermostat.

Here's a clue as to why: The instruction manual is more than 150 pages.

Sachs recalls that when Apple introduced Macs to the media, the computers had no manuals. "Why should a thermostat be harder?"

Therein lies the sad history - and the roots of a promising future - of a device that is vitally important. Heating and cooling consume about 50 percent of household energy use, and thermostats control temperature.

Time was, people had to change the settings by hand.

Programmable thermostats were supposed to make saving energy, and money, easier. You could set the control to heat the house in the morning, reduce the temperature in the day if no one is home, bring it back up for the evening, then lower it again during the night.

If properly used, the federal government's Energy Star website contends, a programmable thermostat can cut 20 percent off a family's heating and cooling bill. Or, on average, about $180 a year.

Energy experts assumed that was happening. By the late 1990s, the devices were being sold at low prices, or even given away, by utilities as a way to help people save energy, said Sachs, a senior fellow with the American Council for an Energy Efficient Economy, a nonprofit advocacy group.

Turns out they were wrong.

Several studies - one was titled "Programmable Thermostats That Go Berserk?" - found that either the programmable thermostat didn't make any difference or, worse still, it led to more energy consumption.

People would think they had the device turned down, and the house would be 80 degrees in winter.

In a study published last year, Alan Meier of the Lawrence Berkeley National Laboratory in California and his colleagues found that even though 85 percent of the respondents contended they were using the programming features, photos proved that 45 percent of the thermostats were actually on "hold" - unprogrammed.

In interviews, the researchers heard common themes: "I don't touch it." "I don't want to mess it up."

Then Meier's group set up thermostats in the lab and brought in 29 people to try to operate them.

The first task was to switch the thermostat from "off" to "set heat." Some people did it in less than 10 seconds.

But 26 percent weren't able to do it at all. Even though the researchers provided instruction booklets.

Energy Star had suspected as much.

The federal energy program sets efficiency standards for equipment, and products that meet the standards can carry the Energy Star logo.

In 2009, Energy Star suspended its programmable-thermostat program.

"Not that there was clear evidence they weren't" working as intended, said Abigail Daken, Energy Star's product manager for heating and cooling. "But there was not enough evidence that they were."

Now, Energy Star is working on a new thermostat initiative, and they're trying to devise a numeric rating for how easy something is to use. "That turns out to be a novel thing to do," Daken said.

And difficult. She can't say when the new program will launch, but the agency is aiming for this year.

Liz Robinson, of the nonprofit Energy Coordinating Agency in Philadelphia, still swears by programmable thermostats, which are key to its weatherization program for low-income residents.