How do you like the nest t-stat? I've been thinking about getting a few, but as nice as they are $250 a pop is pricey. We have three zones with the forced hot air part of the system, we could get away with only replacing two, but that's still $500. I do like being able to monitor run time, temp remotely etc. we couldn't use the first gen because our house has two stage heating and cooking and it wasn't compatible, but the new one is. I would love to get your opinion on it since you have used it first hand.
Mostly, I've been happy with it, but I had to readjust my expectations to meet reality. When it first hit the market, (and the technology websites) it was billed as "the thermostat of the future." The final realization of smart-grid, and fully integrated home automation. The reality is that although it is capable of this, Nest has chosen not to do much about it. (yet?)
So what it actually is is a nice upgrade to a regular programmable setback thermostat.
It has been absolutely reliable - zero maintenance. Not requiring running a dedicated power wire as some other wifi thermostats do was also nice. Installation was trivial, but any thermostat is.
The motion sensing auto-away works well. This might be the most energy-saving component of the whole system. The phone app is handier than one might think. If I go to bed early and read a book, it is nice to be able to pick my phone up off the nightstand and turn the furnace down to the "overnight" temperature a bit early. I've also been known to use the phone app to bump the temp up a couple degrees if I'm on my way home with friends, to make it a bit more comfortable for them.
As much as it is billed as an energy saving device, it is really designed for the people that leave the system turned on year-round, changing from "heating season" to "cooling season" automatically. During the spring and fall months where I prefer to open windows, it and I tend to not get along as well.
A good example of this would be if I wish to just circulate air on warm-ish summer days. There is no "fan only" mode. Instead, I have to set to "cool" but set the temp to 90, (so it doesn't actually cool.) then switch the fan to "always on."
With the information that the device has at its disposal on indoor and outdoor temperature and humidity, I think that the programmers could design it to infer quite a bit more about my intent.
I've heard that the new model is a bit less expensive, and also has a slightly slimmer profile. Having to buy three of them would hurt, but the website and phone apps (Android or iPhone) are clearly designed for this. You are allowed to name each device for a particular room or function. My home is a simple forced air, single zone. The thermostat is centrally located in my dining room.
In the end, I'm glad that I have it, and I do believe that it is one of the best (if not the best) on the market. I just hope they keep at it, and keep expanding the capabilities. I know it can talk to my gas meter for example. I think it'd be cool to be able to know *exactly* what I'm spending on heat, and how I could adjust it to save more.
I'm a technology person, but not necessarily an early adopter. This was one major exception because I liked the concept, and the vision. And although $250 was expensive, it's a heck of a lot cheaper than a solar or wind installation. It seemed like a cause I could support.