Oy. The unit of heating/cooling temperature comparison is the degree-day, not the average temperature of the month.<p>For each time period, take the difference from your desired temperature. If you have an acceptable range, take the difference from the near edge of that range.<p>e.g. with a desired range 65-75, a 40 degree day counts as negative 25 and a 90 degree day counts as positive 15.<p>Keep track separately of positive and negative.<p>Now you have a record of how much you needed to cool or heat. Local newspapers -- remember those? -- will usually keep track for you on their weather page.<p>That's a suitable basis for comparison. Not monthly average temperature, not average high, not average low.
In Texas, companies give away Nests [0][1] to lure customers, thanks to the deregulated market. Competition is so healthy, they are even trying to capture 'green' customers who use less.<p>[0] <a href="http://www.greenmountain.com/nest" rel="nofollow">http://www.greenmountain.com/nest</a><p>[1] <a href="http://www.reliant.com/nest" rel="nofollow">http://www.reliant.com/nest</a>
Depends on the property.<p>In a oil burning boiler property with 8 baseboard zones and 8 Nest units, it saved me a thousand dollars a month all winter. Paid for itself the first winter.<p>Previous thermostats were programmable "eco" models that I kept programmed and used away/vacation modes on.<p>Savings was from being able to see on/off cycles for all 8 zones to better balance them, so boiler was on less overall.<p>I've recommended them to others and use one in a loft as well. Every installation is saving at least 10%.
He's confusing kilowatts with kilowatt hours? They mean very different things. kW is a rate (kilojoules/sec) of usage (power). kWh a stackable amount (in the sense that you can stack money) of energy and is what the electric company charges you for. A basic mistake like this makes me question the validity of the results.<p>I'm in the market for 3 new thermostats and was hoping this article would help me with my decision. Presently, I'm leaning toward an Ecobees (<a href="https://www.ecobee.com/" rel="nofollow">https://www.ecobee.com/</a>) thermostat which has a lot more features than the Nest and even has an API. It seems to be the Android of the thermostat world where Nest is the iPhone. Features vs polish.
Nope, it's not worth it. And this data does not prove it is.<p>I need to know everything about the conditions prior to installing a Nest. In particular, I need to know about the thermostat and, if programmable, how it was programmed. I also need to know about living patterns. Did anything change? Was the programmed temperature higher in the summer and lower in the winter with Nest or was it set to about the same conditions?<p>In terms of energy efficiency. How is the house insulated? Can you add insulation to the walls or attic? Are the windows double-insulated? Do you use a whole house fan in the summer to cool the house at night? Do you have a multiple zone system so you don't have to heat or cool the entire house when you spend all day in, let's say, an office or the kitchen? Is it a two story home? Do you push hot air down in the winter in order to equalize the temperature? Do you have attic ventilators?<p>I see Nest as more of a neat gizmo with lots of marketing behind it than a real solution to a real problem. To be sure, the real solution requires a lot more work than bolting a piece of slick looking electronics to a wall. The payoff from a real solution would almost certainly be far greater and it doesn't have to cost a lot of money. For example, I use a $200 fan to cool my home at night (taking advantage of my local conditions). We have probably used the air conditioner a grand total of four weeks in the last three years. The savings in three years are already in the thousands and the investment was $200.
For me, it made a larger difference in my awareness of how much energy I actually use. Before nest I simply programmed my thermostat once and never touched it again because of the pain. Now I consciously adjust the temperature throughout the day from my desktop or phone. Just being able to walk out the door and turn the temp down from my phone if I'm suddenly not going to be home for a while is savings enough for me. I'm sure there are other thermostats that do the same thing but nest has done their advertising right and their interface/product design is top notch.
I think it would be worth looking at this using "degree days". (Degree day stats from Wunderground, I eyeballed his KW since no firm numbers are provided).<p>* August 2011 vs. August 2012: 809 cooling degree days vs. 594 (1.36x). 2100 KW vs. 1500 (1.4x)<p>* January 2012 vs. January 2013: 544 heating degree days vs. 595 (0.91). 3000 KW vs. 2000 (1.5x)<p>So accounting for the weather with "degree days", with A/C it looks like there was no savings, but with heat it made a massive difference.
There is also the "poor man's nest" - the Filtrete 3M 50 which is $89 on Ebay and fully wifi supported with a well-documented API and fantastic Android app:<p><a href="http://www.ebay.com/sch/i.html?_trksid=p2050601.m570.l1311.R1.TR11.TRC1.A0.Xfiltret&_nkw=filtrete+3m50&_sacat=0&_from=R40" rel="nofollow">http://www.ebay.com/sch/i.html?_trksid=p2050601.m570.l1311.R...</a>
I'm not sure looking at the pure money saving in terms of lower energy is the way to go, since a lot of the benefits are more intangible than that. The ability to detect when you're away, automatic scheduling and easy control from a smartphone are pretty big benefits for me but they'd be hard to quantify in terms of being "worth it".<p>As others have pointed out, you can achieve a lot of that with other (cheaper) products. But to be honest, I think Nest's main strength is making the features easy and fun to use rather than having totally revolutionary new features. But that's the Android and Iphone claim to fame in the smartphone world, and they did OK ;)
This needs to be correlated to the weather/temperature pattern of the two years since the nest is on your HVAC. Much of the US has had a milder summer and winter than the previous year; it may be the same for you.
I live alone in a house, in Phoenix. I use pynest to set my Nest to "Away" when my iPhone leaves the network (I just ping it constantly from a script).<p>My power bill is a <i>lot</i> less than it was pre-Nest, and it requires no effort. Accessing the Nest when I'm about to head home is a nice benefit, too, to get the house cool before my iPhone is detected again.<p>(I have a sporadic schedule so the auto-away feature wouldn't work for me).
I had a Nest early since I preordered it. Unfortunately it just died so I'm not the happiest person.<p>But, over the 1.5 years I had it I saved about 3% from previous years with a dumb thermostat. This doesn't recoup the cost at all.<p>One reason the savings was so low was that the firmware on the Nest was very inadequate during the 1st year. It didn't even do automatic heating/cooling on a schedule. All that was resolved last year.<p>The other reason is that the Home/Away detection is worthless for me (and I suspect many folks) because the thermostat location isn't in the traffic pattern of the house. I've pleaded with them to do a remote sensor but so far they don't care. Most of the new modern wireless system have the ability to add remote sensors so they're being left behind quickly.<p>Even so I'm not disappointed in the Nest. It's cool and I am very pleased to have wireless access via my smartphone to the temperature settings.<p>But they need to do a lot a work to get back to the level of companies like Honeywell and their distributed system.
The failure stories I have heard convince me these are not fail-safe devices. If the thing shuts down in the winter and doesn't restart correctly, and you are away, you could come back to frozen/burst pipes. (Probably hasn't happened yet, but the failures have happened, so it's likely just a matter of time.)<p>So I would only use one of these paired with a conventional thermostat serving as a safety net, in case the Nest fails. But then I resent having to compensate for a manufacturer that cannot be bothered to build the failsafe into their own product in the first place.
I live in an area where you rarely need air conditioning. Many homes around me do not even have them. However we do need heating from about November to about April, but it rarely does get below freezing. With that said my power bill is about 50/month for gas and electricity. I really didn't need a Nest, but it is certainly a fun tech toy to have. Being able to remotely turn on my heat or AC remotely is pretty nice when you want you're on your way home. So even if I don't make back the $249 that I spent, I still feel that it is worth the money.
I believe the "auto away" detection feature on our Nest has made the biggest impact on our energy bill. Nowhere close to what the OP is saving, but I'd bet it's in the $50/year range.
The real selling point is the aesthetics. That's why I bought it anyways.<p>The self-learning scheduler is nice, but I could easily program a manual one in a few minutes.
Feels like a tipping point for Nest. Someone like this could be the next Apple.<p>I feel strongly a few of these Internet enabled devices will pave the way for a new industry. Imagine Nest being purchased by every household (like the iPod) and then moving on to other products.<p>At some point it feels like they could charge a subscription. Would you take a free device and pay them 10$ of your 30$/month savings?
i'm sorry, am i missing something here...? what exactly is wrong with paying $250 for a very nice piece of technology with a great user interface?<p>is this just a symptom of their chosen marketing strategy (saves you money!)?
It is very unlikely that this is accurate, or there are substantial externals that are not being accounted for (e.g. stopping using a desktop as much as a tablet gets heavy usage) -- the difference between 2012-01-01 and 2013-01-01 is just <i>way</i> beyond what even the biggest Nest hyper claims.<p>Outside of savings that grossly exceed even the best expectations, when questioned whether they used a programmable thermostat already (the absolute bog standard $20 variety automatically dropping the temperature in a manner that is close to optimal for about 95% of people), the author gave a very wishy-washy answer that didn't actually answer the question.