Nest smart thermostat goes on diet, works with more home energy systems

The new edition is 20 percent thinner than the original and works with 95 percent of all the residential cooling and heating technologies sold in the United States, according to Nest Labs.

The second generation of the Nest Learning Thermostat, which was sold out before its original release last year, is making its debut in North America this week.

The biggest aesthetic design change is the technology's thinner profile (it is 20 percent slimmer than the original), as well as a new stainless-steel exterior ring that helps it blend into decor more easily. It will retail for about $249, and will ship to customers in the United States and Canada in mid-October (although you can pre-order it right now). The original version of the thermostat is now priced around $229; it can be updated with the new software features described below.

From a features standpoint, the new edition adds new integration capabilities -- it now works with an estimately 95 percent of all the residential heating and cooling systems currently sold in the United States, according to Nest Labs.

Nest AutoAway

"In the past year, we've accomplished a number of notable milestones, from having Nest thermostats connected -- and saving money and energy -- in every U.S. state and across Canada to achieving the best-seller status at Lowe's, Amazon and Apple's online store," said the company's founder and CEO Tony Fadell, in a prepared statement. "Our mission is to keep people comfortable in their homes while helping them save energy, and with the next-generation Nest Learning Thermostat, we're able to spread that comfort and savings to enve more homes -- and to help higher-efficiency systems perform the way they were meant to."

The updated Nest Learning Thermostat includes update system software that has four main advantages over the existing technology:

1) It better matches some of the more sophisticated features in home energy systems. For example, if you need the house to be a certain temperature by 6 a.m. when you wake up, Nest will figure out the best time to get the heating or cooling to kick in. The same goes for radiant heating system and heat pumps.

2) It includes additional auto-away and auto-schedule options, for when you aren't in the house and want to conserve energy.

3) It can be controlled with additional mobile platforms, including Android tablets, Nexus 7 and Kindle Fire. (The system already supports Apple, iPhone, iPad and Android smartphones.)

4) You can now program the system in French (which is a must for the Canadian market) or in Spanish, which are now included along with English as default languages.