At its simplest, a thermostat is easy to understand: it’s a switch that opens when it is warm enough, and closes when it is too cool. The switch controls the heater. When it gets cold, it turns on the heat. When it is warm, it turns off the heat.
And for quite a long time, that’s all a thermostat was: a metal strip that bends when it changes temperature, wound into a coil to amplify that bend, with a tilt switch on the end. You turn the dial—which turns the whole coil—until the tilt switch is balanced where you want the heat to shut off. As it heats up the coil unwinds, tips the switch, and the heat shuts off. When it cools off, the coil winds back up again until the switch tilts over and starts the heat again.
Things are more complex now.
To start with, there is now air conditioning. Which needs the opposite behavior: Too hot turn on/cool enough turn off. So they put another tilt switch on the strip, pointed the other way. Or two strips with two switches.
Then solid-state electronic thermostats appeared. Now you could do things like automatically turn down the heat at night when you’re under a blanket, and during the middle of the day when you’re at work. But they were so complex and hard to figure out that most people who bought them never programmed them right. Or at all. Or they programmed them once, and then the first time their needs changed they set them to override and left them.
Recently, there’s a new breed: Internet Thermostats.
with an Internet thermostat, you can do all that complex programming in a browser, instead of with a few buttons the size of pinto beans (“SET TIME. UP, UP, UP, UP, Oops! Missed it! Have to scroll all the way around again; UP, UP, UP…” no wonder they’re not well utilized), and because they’re connected to the Internet you can change your thermostat on the fly, from work, or with an app on your phone. If (like me) you keep an erratic schedule, you can tell it to turn down when you leave the house and then tell it to turn up when you’re on the way home.
So I’ve been shopping for Internet Thermostats. There are a few I have looked closely at:
The Allure is huge. Really big. It has built-in bluetooth speakers so you can stream music to it, and it can act as a digital picture frame. The thing that makes it unique is that its app knows where you are at all times in relation to the thermostat. So the farther away from home you get, the further down the heat goes, and as you approach it turns it gradually back up. So you theoretically always walk into a warm comfy house, because the heat is never down further than it can be brought back by the time you get home, but it’s always down as far as possible. I’m really impressed with the ideas, but I won’t be buying an Allure, because they have chosen not to account for radiator-heated houses in their programming. And they’re still very 1.0 feeling; and since like any other Internet-connected thing you rely on the vendor sticking around, I’m a little wary. Also, the most expensive of the ones I have seriously looked at.
The Nest is dead sexy. Sleek, postmodern looking. You program it with your best guess of what you want. And then over the first few weeks and months you own it as you tweak the temperature up or down, it modifies what you told it to match what you actually want. It can see when you’re home and turn back up if you’re home off schedule. It can give you little prods to modify your use of your climate control to save energy. The basic philosophy seems to be for it to manage itself based on its perception of your needs, rather than being easy for you to manage. And they were just bought by Google. Which means they’re probably not going to go away anytime soon. But the Internet is full of stories of people who bought them and did not enjoy the experience as much as they thought they would. There were serious problems with them in the early revs; stories of them heating people’s houses to the 90s. And there have been complaints that it’s only accurate to 3°F (A modern digital thermostat is generally accurate to 1°F). But I’ve spoken to people who have them and they have not noticed that being a problem; I suspect that what’s really happening is that the Nest is consistent, but reading lower or higher than the thermostat it replaced. The posts I have found from disgruntled users are not that the range is too wide, but all about how it’s reading “too high by 3°F”. But who cares? The point of the Nest is that you don’t have to micromanage the numbers. You tell it you feel too warm or too cold and it fixes it and learns from the experience. So what if you originally set it to be 68°F and now that you’re comfortable it’s reading 70°F, or that when you put your old thermostat up next to it the readings are different?
Honeywell is well known in the HVAC world (and the world of industrial control in general). Almost all of you have touched and probably owned a Honeywell thermostat: the classic round thermostat with the classic 40s industrial design. They’ve been making modern digital controls for things for years. But they’re relatively new to the Internet Thermostat game; they didn’t realize there was a demand. And their products haven’t matched the design perfection of the Honeywell Round Thermostat since, well, since that item. Most of their current thermostats are big flat uninspiring plastic boxes with big flashy screens. You can program the whole shebang from the screen. My issue with them is basically the same as my issue with the Internet locks made by the traditional lock manufacturers: They took their existing product (which admittedly was among the best in its class of “Programmable Thermostat”) and added Internet to it. It’s not an innovation, it’s just got the Internet bolted on. The difference between their Top Of The Line Thermostat With Internet Control and the next one down is: Internet control. And also a flashier screen: you can adjust the screen’s background to match the paint on the wall behind it. Wow. Besides being able to control it via the Internet, it’s not using the power of the Internet.
It’s a simple-looking plastic thermostat. But it’s programmable via the Internet and it has optional ZigBee. So you can use it to control a ZigBee-controlled outlet and for instance use that to drive a humidifier (since it has a humidity sensor). You can use external ZigBee temp sensors (only ones that you buy from EcoBee) so you can make some other place in your house the place it sets temp to. Or average your sensors so the house is closer to your ideal temp overall. Or make it act smarter in reaction to the outside temp. (For instance no need to start the AC when it’s hot in the house but cold outside. Just wait.) Or let it interface with your power meter where available to let the electric company control your HVAC. But the whole interface seems clunky to me. And ZigBee is not the direction the rest of the consumer home control world seems to have gone. So really the ZigBee parts are a lot less cool than they seem, and without them it’s just an overpriced programmable thermostat you can program from a browser. And they really really want you to hire a contractor to install it; you can get one from Amazon or eBay, but if you try to get one from the EcoBee website it tries to hook you up with a contractor. Which neatly eliminates complaints from Joe Suburbia about it not working after he hooks it up all wrong, but makes it annoying for someone like me who mostly knows what he’s doing.
Visually it’s nicer than the Honeywell. You can configure it to know there’s no AC, and then it will just not show you those options (others might do this as well, actually. But these guys tout it like it’s a big deal). It’s got a big pretty screen: “The thermostat that thinks it’s a picture frame.” But Internet/Wifi is an extra-cost option (that adds an afterthought-looking blob to the side of the device), and once it’s installed it gives you much more analytics, but not any more control: still the same “4 periods per day” programmable thermostat as ever. Meh. It’s somewhat cheaper than most.
Misc Z-Wave thermostats
There are many. They all look and seem to act about the same. They’re not very bright. They are controllable via Z-Wave, so they expect your Z-Wave controller to be doing the heavy lifting of making them dance. Which is fine, but not what I would ideally want. And none of them have had a talented industrial designer lay hands on them. Visually they’re all kind of blah.
Industrial Controls for the Home
Several manufacturers of Internet-controllable industrial thermostats (EG: Bayweb, Network Thermostat Co., Proliphix) have realized people are buying their products and installing them in their homes, and have come out with models more targeted at the home user. I’m guessing these people were the early-adopters who so desperately wanted Internet control they were willing to suffer hideous design and abominable user interface to get it. Because these things are ugly to look at and appear to be a huge pain to configure and manage; worthwhile when you’re managing the energy usage of an entire enterprise and that’s your job, but not OK for a home user who really wants set-and-forget convenience. I’ll pass.
…and now its the end of the heating season, and I don’t have central air. If I had to buy one tomorrow it’d probably be the Nest, but I have a few months more to stew and fret about all these options before I have to get around to buying and installing. And a few months for new contenders to appear.