Nest Learning Thermostat

The Nest Learning Thermostat by Nest Labs is an electronic, programmable, and self-learning Wi-Fi-enabled thermostat that optimizes heating and cooling of homes and businesses to conserve energy.^[1] It is based on a machine learning algorithm: For the first weeks users have to regulate the thermostat in order to provide the reference data set. Nest can then learn people's schedule, at which temperature they are used to and when. Using built-in sensors and phones' locations it can shift into energy saving mode when it realizes nobody is at home.^[2]

Specifications

Device Photo	Version	Released	Wi-Fi	802.15.4	24 V	120– 240 V	Multiple Zones	1 - 2 Stage Cooling	1 - 3 Stage Heating	Forced Air	Radiant	Heat Pump	Oil	Gas	Electric	Hybrid Systems	Humidistat
	1.10	Q4 2011	Yes	Yes	Yes	No	Yes	Single Stage Only	1-2 stage only	Yes	Yes	Yes	Yes	Yes	Yes	No	No
	1.12	Q1 2012	Yes	Yes	Yes	No	Yes	Single Stage Only	1-2 stage only	Yes	Yes	Yes	Yes	Yes	Yes	No	No
	2.6	Q3 2012	Yes	Yes	Yes	No	Yes	Both	All	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes
	2.8	Q3 2013	Yes	Yes	Yes	No	Yes	Both	All	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes

SKUs / Model numbers

• T100577 is 1st Generation, released only in the US
• T200377 is 2nd Generation, UK release
• T200477 is 2nd Generation, Canada release
• T200577 is 2nd Generation, US release
• T200677 is 2nd Generation, France, Netherlands, and Belgium release
• T3007ES is 3rd Generation, US release ^[3][4]
• T3010FD is 3rd Generation, France release ^[5]
• T3010GB is 3rd Generation, UK release ^[6][7]

T200477 and T200577 are technically the same ^[8]
T200377 and T200677 are technically the same, except for the power plug used for the USB charger ^[9]

Hardware

The Nest Thermostat's front screen

Nest Learning Thermostat showing weather's impact on energy usage

Nest is compatible with most standard HVAC systems that use central heating and cooling and uses industry standard connections to facilitate the control of these appliances.^[10]

Nest consists of two primary pieces of hardware. The display contains the main printed circuit board (PCB) and rotating ring, and the base (pictured) houses the connection terminals, bubble level, and holes for wall anchors. Neither can function independently; if separated, the display becomes inactive until reconnected to the base.^[11]

A special version of Nest is available in Europe, which is capable of controlling 120–240 V heating systems. The Nest is paired with a "Heat Link" device, which contains the circuitry required for controlling the mains-voltage heating system.^[12]

Software

The Nest Thermostat is built around an operating system that allows interaction with the thermostat via spinning and clicking of its control wheel, which brings up option menus for switching from heating to cooling, access to device settings, energy history, and scheduling. Users can control Nest without a touch screen or other input device. As the thermostat is connected to the Internet, the company can push updates to fix bugs, improve performance and add additional features. For updates to occur automatically, the thermostat must be connected to Wi‑Fi and the battery must have at least a 3.7 V charge to give enough power to complete the download and installation of the update.^[13]

The Nest Thermostat has had a number of software updates.^[14]

Many have commented on the company's "Nest Community" regarding the lack of prominent display of the current temperature.^[13]

The operating system itself is based on Linux 2.6.37 and many other free software components.^[15] To comply with the terms of the GPLv3 license under which some components are available, Nest Labs also provides a special firmware image which will unlock the system so that it will accept unsigned firmware images. While the thermostat software by Nest Labs itself remains proprietary, a third party has reimplemented the basic logic in an open source replacement called FreeAbode.

Weave

Nest devices interconnect with each other using a protocol called Weave, which is based on IEEE 802.15.4 and Wi-Fi 802.11 b/g/n.^[16]

Availability

Nest is currently available for sale in the United States, Canada^[17] the United Kingdom.,^[18] Belgium, France, Ireland and the Netherlands.^[19] It is, however, compatible with many heating and cooling automation systems in other countries.^[20] Nest Labs have surveyed existing users known to be outside the areas where it is officially available. Use of the thermostat outside the United States and Canada is complicated by the software setting time and other functions based on the ZIP code. For international users this means they must either disable Wi‑Fi to set the time correctly or use the nearest U.S. zipcode which may result in erratic behavior as the thermostat makes faulty assumptions about inactivity corresponding with either sleep or the home's occupants being away.^[21]

Recently a man-in-the-middle hack allows worldwide users to set up their timezone and local weather.^[22]

In an effort to increase the number of homes using their learning thermostats, Nest began to partner with energy companies. In February 2014, Direct Energy and Nest laboratories launched their Comfort and Control plan. The plan allowed Canadian customers in Alberta to receive a learning thermostat when they signed up for a 5-year electricity contract.^[23] In April 2014, Nest announced a partnership with the United Kingdom energy supplier nPower. The partnership offers customers a cut on the Nest installation price and locked energy prices for 5 years, when customers receive both gas and electricity from nPower and paying with direct debit.^[24] In June 2014, Direct Energy and Nest Laboratories expanded the package to Direct Energy's United States market.^[25]

References