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Nest white paper shows savings from smart thermostatUS consumers using Nest Labs smart thermostats shaved up to US$145 off their annual heating and cooling bills, according to third-party research carried out on behalf of the Google-owned company.

In a white paper released this week, Nest presents findings from three studies of how the Nest Learning Thermostat affected utility bills before and after installation.

Two of the studies were funded, designed and evaluated by utilities - one  in Oregon and the other in Indiana. The third study was performed by Nest using a national sample of Nest customers across 41 states in the US who had also enrolled in Nest’s MyEnergy service.

The white paper concludes that all three studies showed savings equal to about 10%-12% of heating usage, and electric savings equal to about 15% of cooling usage in homes with central air conditioning.

The reduction in electricity consumption translates to an estimated annual average savings of US$131 to US$145 a year, according to the data, which with the first generation product retailing at US$199 means that the product pays for itself within two years.

Smart thermostat market

Quby buys Joulo USB logger for home thermostatThe findings come as activity in the smart thermostat market steps up with acquisitions and new market entries.

A spin-out from the University of Southampton in the UK was bought out by Quby, a leading European smart thermostat and energy display developer.

The acquisition of Joulo announced this week means that Quby can access advanced algorithms as well as a hardware product - the Joulo USB temperature logger.

The product works by being positioned on top of a home thermostat. It gathers data over the course of a week that can then be uploaded onto a home computer and analysed using algorithms to present consumers with energy consumption data and advice.

Commenting on the deal, Joris Jonker, CEO of Quby, said the deal was also an opportunity to expand into new markers.

Mr Jonker said: "We are excited to announce this acquisition. This is a great opportunity for Quby to become more active in the UK by using Joulo as a springboard for our smart thermostat offering."

Utilities and smart thermostats

Meanwhile, Canadian smart wifi thermostat company ecobee has confirmed that it will be involved with new utility programs in 2015 including partnerships with North Carolina's Electric Cooperatives and Xcel Energy.

And EDF Energy unveiled a new smart thermostat device this week as part of its new HeatSmart system.

The device, which has been developed by consumer electronics specialist Netatmo, builds on smart meter functionality by giving people remote control over their heating systems through their smartphones, tablets, or computers.

The company said the new device was available to EDF customers and non-customers for GBP199, including installation and a two-year product and one-year installation warranty.

Smart thermostats are designed to reduce energy bills and carbon emissions by allowing people to automatically turn off boilers or lower heating levels when they are unexpectedly out.

EDF said the new HeatSmart system also features a raft of functionality designed to help optimise home environments, including the ability to programme a weekly routine into the app and then use an auto-adapt function to optimise the heating of the building.

[Read more - Nest Learning Thermostat: Energy Bill Analysis Results]


  1. From the writeup it sounds like only “Nest” brand devices were tested, which is perhaps is reasobable if they paid for the study.
    But it seems that probably any programmable thermostat, properly programmed and functional, would have produced a similar savings.
    The main differences amongst programmable thermostats are: First, the ease of programming, and, second, the number of individual time segments that can be programmed. Other differences, relatively minor, are appearance and the number and type of batteries required.

    Since heat lost is proportional to the difference in temperatures, and since heat lost is the primary cost of running a heaating system, it is clear that setting to a lower temperature will always produce a savings. The situation for cooling is similar except that energy is also consumed removing humidity, and the increase in humidity is not primnarily driven by a temperature difference.

  2. When heating the lower the temperature difference, the slower the heat transfer. But what’s not addressed in the article is that a thermostat feels air temperature while the entire contents of the home are subject to indoor temperature and they transfer their heat more slowly. Radiant energy is that which is stored in all the contents of the home. As that radiant energy is transferred to cooler room air, the thermostat, at a lower setting, doesn’t need to respond and a form of savings is realized as the room temperature drops. What’s not explained is how long the lower temperatures are maintained. All the radiant energy lost with lower temperatures must be put back to warm the contents of the room. How long that takes is dependent on OAT and how far down the setback was relative to the occupied temperature desired.

    If a programmable t-stat is properly programmed and those setbacks for heating or set ups for cooling (due to humidity control and capacity issues for AC, step-up savings can be very difficult to achieve with cooling) I believe the savings would be comparable. In fact, it is my belief that the only way any of the smart thermostats save, is to be a little smarter than the thermostat operator.

    When a home AC system is set to maintain a specific temperatures, the equipment works to remove heat as it enters the home. If much of that heat is not removed due to a dwell time to achieve a higher set point, heat will continue to accumulate in the home. Keep in mind that there is a limitation as to how much heat can be removed from a building on a PER HOUR basis, the same basis on which the unit is rated (among other things). Time is frequently omitted when we talk about a 2, 3, 4 or other tonnage system. That’s 2, 3, 4 tons PER HOUR! Build up a significant heat load in the home, say 70,000 Btu’s with a high set point, and with heat coming in at 36,000 Btu’s per hour and a 3-ton system trying to lower the room temperature to a new set point and disappointment will prevail as the equipment is removing only 36,000 Btu’s per hour and the 70,000 Btu added load remains, until the incoming load decreases to less than the capacity removal of the system. In most homes, that sometime after 6pm and may not be until after 9pm in many instances. So while some savings may be realized, discomfort is most expected companion in the home.