Is a Nest worth the money?

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.

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.

Keep track separately of positive and negative.

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.

That's a suitable basis for comparison. Not monthly average temperature, not average high, not average low.

[0] http://www.greenmountain.com/nest

[1] http://www.reliant.com/nest‎

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.

Previous thermostats were programmable "eco" models that I kept programmed and used away/vacation modes on.

Savings was from being able to see on/off cycles for all 8 zones to better balance them, so boiler was on less overall.

I've recommended them to others and use one in a loft as well. Every installation is saving at least 10%.

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 (https://www.ecobee.com/) 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.

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?

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?

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.

* August 2011 vs. August 2012: 809 cooling degree days vs. 594 (1.36x). 2100 KW vs. 1500 (1.4x)

* January 2012 vs. January 2013: 544 heating degree days vs. 595 (0.91). 3000 KW vs. 2000 (1.5x)

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.

http://www.ebay.com/sch/i.html?_trksid=p2050601.m570.l1311.R...

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 ;)

My power bill is a lot 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.

(I have a sporadic schedule so the auto-away feature wouldn't work for me).

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.

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.

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.

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.

But they need to do a lot a work to get back to the level of companies like Honeywell and their distributed system.

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.

The self-learning scheduler is nice, but I could easily program a manual one in a few minutes.

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.

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?

is this just a symptom of their chosen marketing strategy (saves you money!)?

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.