I received an email announcement that included information from a company about how it helped Honeywell redesign the user interface for the new Prestige family of home thermostats. According to Honeywell’s research, “…almost 80 percent of its programmable thermostats were either being left un-programmed by homeowners, or were programmed incorrectly.”
I agree with the results. Before we left on a trip I told my wife I would program the air-conditioner settings, but she wanted to know how to do it on her own. I wrote the instructions for the time and temperature settings for weekdays and weekends. I had about 30 steps written before I decided my wife could take it from there. She did and had the thermostat set properly. But why should it take 30 or more written steps?
I gather Honeywell’s customers had similar problems. The new graphic interface no longer relies on a fixed-icon and segmented LCD. Instead, the design company created a high-definition color-LCD user interface that will guide home owners through set-up steps or they can proceed on their own–after they learn the steps. Unfortunately, the email doesn’t note how many steps the Prestige thermostat (about $US 350) requires.

Even with a new user interface, though, the Prestige thermostat comes with a lengthy set of instructions. Must homeowners read these instructions or can they figure out how to set up a program with only the “Guide me…” or “I’ll do it myself” menus? Information for installers looks complicated, too. I thought about downloading a demonstration program that would let me go through a dealer/installer setup sequence. But, the instructions require 37 steps and involve many “save this,” “open a folder,” “copy files” and so on. Dealers or distributors also must program over 70 setup configurations, although some can remain at their default setting.
The lessons here seem to be: First, even a nice-looking “intuitive” human-machine interface (HMI) can become complicated and require detailed descriptions, instructions, and diagrams. Second, don’t forget about installers and service people. They also need an easy-to-use HMI that makes set up, installation, test, and repair as easy as possible. I’m not sure a nice color interface and 18 pages of instructions is the way to go. –Jon Titus