The Nest Learning Thermostat, 2nd Generation frees users from the hassle of programming a thermostat while providing the conservation benefits of a programmed device. It accomplishes this by creating a customized temperature schedule and a built-in activity sensor that automatically shuts the thermostat down when no one is home. Every time the users change the temperature, the Nest Learning Thermostat learns and anticipates the appropriate preferences based on people’s habits. When no one is home, the built-in activity sensors recognize this and promptly turns off the heat or air conditioning. When users adjust the temperature, Nest informs them how long it will take to reach that target so that they are always informed of the amount of energy expended by their choices. With this information, users are enabled to make more conservation-friendly choices. In the United States, thermostats control approximately 50 percent of the energy consumption in the average home. A programmable thermostat like the Nest can reduce a typical annual energy bill by as much as 20 percent. In 2011, Nest launched the first-generation Nest Learning Thermostat, disrupting an industry that had seen little innovation in decades. The response was immediate and overwhelming, with consumers enthusiastically embracing the new programmable thermostat. The challenge for the second-generation project was to make it even better. In addition to making the Nest Learning Thermostat, 2nd Generation compatible with 95 percent of all heating and cooling systems, it was designed to be thinner and use better materials, to offer improved sensing functionality and to be easier to install. The user experience begins with the simple and quick installation process. A 15-minute installation time is not unusual. In fact, a number of YouTube videos show children installing Nest. The spirit of the design of the Nest Learning Thermostat, 2nd Generation is embodied by the head unit: a svelte circular form factor that presents a refreshingly simple concentric user interface. Turn the ring to adjust the temperature and press any part of the lens assembly to select. The color display is slightly magnified by the optically polished lens. A proprietary occupancy sensor sits underneath the display. Viewed from more than a few feet, this element disappears, blending with the display lens surface. The Nest harmonizes visually within the home. The head unit ring is solid turned stainless steel. While attractive on its own, the true function of this finish is to reflect the color of the surrounding wall. This is Nest’s chameleon effect, which helps Nest become a part of the user’s home.