Wednesday, December 24, 2014

Ecobee Smart: Why a 5 Year Old Smart Thermostat Design Was My Choice

As we began our renovation project, something that was important to me was the selection of our thermostat. I know most people don't put a lot of energy into that selection, but it was something I wanted to get right. The obvious hipster solution would be the Nest Learning Thermostat, and the first part of this post is going to tell you exactly why I didn't make that choice.

The Nest, because its developers worked at Apple on the iPod, has the obvious benefit of making one cool.  I mean, they sell the nest at the Apple Store, and without a doubt, at introduction, the Nest was the most attractive thermostat on the market:

Nest Thermostat
The Nest is Attractive
The first generation Nest was introduced at the end of 2011, but had some important limitations, like the fact that it couldn't control 2 stage air conditioning systems. The second generation Nest, introduced about a year later, was a more powerful device that could control modern multi-stage systems (2 stages of cooling and 3 stages of heating).  The 2nd generation device even got a software feature that my $60 Honeywell thermostat had in 2003: "smart recovery" (Nest calls it "Early-On"), which basically means that instead of just having a schedule of times to change temperature set points, when it's been offset (turned warmer while you're gone in the summer or cooler while you're gone in the winter), it will achieve the desired temp at the requested time.

Basically, with cheap programmable thermostats (and expensive 1st gen Nests), if you know you get home at 6:00 pm every day, you need to set the thermostat program to a lower temperature sometime before 6:00 to be sure it gets to your temperature by 6:00, and if you want to be SURE it will get there on the hottest days, you need to set it pretty early, maybe 4:00 just to be sure.  With smart recovery the thermostat control logic determines load vs. capacity for your system dynamically and predicts how early it needs to start running to achieve your temp at 6:00.  Some days it might be fine with 5:45, while other days it might have to come on at 4:30.  This is a really important feature if you want to confidently offset your temperature significantly while still being comfortable when you're home.  Without smart recovery you're less likely to offset significantly, and you're going to reap smaller rewards from offsetting because you're going to program to start recovering too early.  It's a basic enough feature for a premium thermostat that it's embarrassing that it wasn't included in the first generation product.

The big selling point of the Nest is that it figures out home usage patterns by using motion sensors to determine when you're gone, allowing it to determine your schedule for you, and addressing the biggest problem with programmable thermostats: people don't actually use them to offset.  The nest starts offsetting for you and learns how much it can get away with before you start adjusting it.  The more it gets away with, the more little green leaves it rewards you with to let you know how it's saving you money.  I'll be honest: this is the point where my eyes glaze over on Nest.  I'm not an idiot, and I don't need an idiot's thermostat.  My thermostats have always been programmed, and, unlike the first gen Nest, they've always included smart recovery capability.  For me, comparing the Nest to a sub-$100 Honeywell thermostat from Lowe's yields: Nest has wifi (that's good), nest is pretty (sure), next costs 4X more (uh, why?).

So what did I pick?  I picked the HVAC engineering nerd's ultimate thermostat: the ecobee Smart Thermostat.  The Smart, introduced in 2009, falls short of the hipster choice in a couple of areas.  First off, let's get this out of the way, it's not as attractive:

ecobee Smart Thermostat
The ecobee Smart Looks Like it Was Designed in 2009

In addition to not looking as pretty, being a relic from 2009, the wifi support is 802.11g, not 802.11n, which is a bummer for some technical reasons.  The Smart's interface is also a resistive touch screen instead of a capacitive touch like the Nest's.  In layman's terms, capacitive touch is what has made smartphones so responsive and what made the iPhone so different, as it was the first big product to use capacitive touch.  Finally, the Smart wasn't available at the Apple Store.

Now that I've gotten that out of the way, here are all the reasons why the 5 year old Smart was my choice in May 2014:
  • Smart is more than a name.  The Smart's software includes all the basic things you expect a any $250 thermostat to do.  Smart recovery, humidity control either using your existing air conditioner or a dehumidifier and humidifier, smartphone integration, home automation integration, consideration of current weather and forecast in scheduling, etc.
  • Web programming.  For whatever reason, maybe the same one so many VCR's used to flash 12:00, many people don't program their thermostats, but the Smart makes it really easy to do.  You can basically get as sophisticated as you want and it's really slick and easy to do just by dragging with your mouse.
  • Reporting.  The online reporting with any ecobee is really slick, but if you want you can download all the data from the system into a spreadsheet and analyze it.  Basically you can see exactly what your thermostat was doing in 5 minute intervals for as long as you've owned it.
  • Multiple inputs and outputs.  This is what really sold me.  With the Smart you have discrete inputs and outputs that can turn things on and off or monitor whether things are on and off, and with the optional Remote Temperature Sensor Module you can hook up extra sensors for different rooms of your house, or OAT, or attic temperature, or whatever.  Now things are interesting.
For our house, we added two Honeywell C7189U1005 Temperature Sensors, one in the master bedroom, and one my office.  That way, at night I can control the temperature of our house based on our bedroom temperature, and during the day, when I'm working from home, I can control the temperature of our house based on my office temperature.  This is the killer feature that every home should have, and for me it was worth not getting rewarded with green leaves and having a less attractive device on my living room wall.

After I made the decision, Honeywell introduced the Lyric WiFi-Enabled Thermostat, which gave me pause. The Lyric looked attractive, modern, and had some functions that didn't exist in the Nest or Smart.  I really liked the idea of their "Fine Tune" feature, which adjusts setpoint based on things like "is it particularly cold outside?" or "is the humidity running a bit high in your house right now?"  In the end, while the Lyric promised to be better than the Nest, sensors in all the important rooms was the killer feature, and I stuck with my 2009 thermostat, and I'm pleased with the selection.  There's really no substitute for controlling the temperature in your actual location.

Finally, a bit of a spoiler for a future post.  If I were choosing today, I wouldn't choose the Smart.  In September ecobee introduced the ecobee3 Wi-Fi Thermostat with Remote Sensor.   Unshockingly, they reached the same conclusion I did with regard to what the killer feature was for a thermostat: controlling the temperature where you're at, not where the thermostat is mounted to the wall.  The ecobee3 supports wireless sensors basically wherever you want them, and uses motion sensing to follow you around your house.  Their slogan is "For Homes With More Than One Room."  I have one sitting on my desk for a customer's home and will write about it soon.  The ecobee3 is attractive, modern, oh, and for you hipsters, it's now sold in the Apple Store.
Ecobee 3 Thermostat and Remote Sensor

Products referenced in this post:


  1. So when are you reviewing the Ecobee3?

  2. Ecobee3 has a mobile app for Android and iOS phones. One of the most impressive things about the Ecobee app is the fact that the home screen of the app looks just like the interface of the thermostat and allows you to control all the features of the thermostat right from the app -