About 51 percent of your home's energy consumption is used for heating and cooling, the U.S. Energy Information Administration tells Reviewed. And that costs money. This is where smart thermostats come in. These thermostats connect to the internet to give you remote control of your heating, ventilation, and air conditioning; and to track your energy use to figure out how to make you the most comfortable for the least money.
The two of the most popular smart thermostats are the third-generation Google Nest and the Ecobee4. Nest grabbed more headlines, partly due to its clean, spare design and easy-to-understand controls, but the Ecobee is no slouch and has made steady advancements. It even offers features the Nest doesn't.
Look and feel
Are you a minimalist, or do you crave information? Nest has won praise for its sleek design. Its silver bezel is intended to reflect the wall it's on, so it blends in. Its display is blank black glass until motion triggers it, at which point it comes to life and displays your choice of current indoor temperature, the thermostat's target temperature, the weather, or a clock (digital or analog). In comparison, the Ecobee4 has a larger black display that won't blend to anything but a slate wall. Its larger display shows temperature, clock, settings, indoor humidity, and can be set to show the weather report as well.
If you are replacing an old thermostat, installing either Nest or Ecobee is pretty easy. You are likely to need at least a Philips head screwdriver for the wall screws, and a small flathead screwdriver for the leads (wires) on your old thermostat. It may be handy to also have a drill, hammer, pencil, wire stripper, and small pliers for straightening old leads.
There are basically two common kinds of installation: with or without a "c-wire." A c-wire offers a constant 24-volt power supply. Don't worry if you don't have one—both thermostats offer a workaround, although it may add steps to the installation. We find the Ecobee's written instructions simpler than Nest's, but both also offer video instructions and a tech help line to see you through.
In the past, the main feature difference between the two thermostats had been Ecobee's wireless remote sensors. A remote sensor lets the thermostat measure temperature somewhere other than where it is mounted, which is valuable if your house heats unevenly, or if your thermostat is in a drafty area. The Nest recently added remote sensors, but there are still differences in the sensors' specs.
Ecobee's sensors have a motion detector to automatically detect which room you are in. The thermostat adjusts so the occupied room is at your desired temperature. If you have several sensors, they work together to get the average temperature throughout your house as close to your target as possible. Nest can have several sensors, but it can only talk to one at a time. You have to manually tell it which one to pay attention to—there is no motion detector. You can set it on a schedule if you know which rooms you use at certain times.
The Ecobee4 (available on Amazon) includes one remote sensor, and additional sensors are $80 for two. The Google Nest 3 (about the same price on Amazon) does not come with a remote sensor. They are available for $40 each.
Smart thermostats are often the gateway for other connected devices—they can interact with lights, motorized window shades, sound systems, smoke detectors, security systems, and more. Both the Nest and the Ecobee can do this, but there are limitations.
After its purchase of Nest, Google decided to shut down the "Works with Nest" program that helped integrate other devices. It will be replaced with "Works with Google Assistant," potentially cutting off some smart home products that currently can integrate with Nest. And it isn't compatible with Apple HomeKit.
Ecobee, on the other hand, will continue to integrate with Apple HomeKit, Amazon's Alexa, and Samsung's SmartThings, Microsoft's Cortana, Wink, Google Assistant, and IFTTT.
Read more: The Best Smart Thermostats
Both offer mobile apps that are pretty easy to use. Nest's minimalist control means there isn't much to learn. Ecobee's app closely mimics the faceplate of the thermostat, so if you can run one, you can run the other.
One way the thermostats save energy is by shutting off the HVAC when you aren't around. But then if you're gone for the day, you don't want to return to a cold or hot house. Both systems use "geo-fencing," which enables your phone to tell the system when you've left home and when you are headed back, so it can adjust the temperature accordingly. However, Ecobee can't automatically geo-fence with Apple mobile devices unless there is a HomeKit product at home.
Using the geo-fencing feature with the motion detectors can cause an annoying quirk. If you are on a long flight, either system may switch back to energy saving mode while your mobile device is in airplane mode. To get your house ready for your homecoming, you have to turn off that automated feature and manually set your home thermostat from your phone. You can turn geo-fencing on again later.
Ecobee says it expects its thermostats to last 10 to 15 years. Google Nest declined to give a time frame when we contacted them but said the average thermostat lasts 8 to 10 years, and the Nest is expected to meet that average. In either case, that is long past the warranty. Ecobee offers a three-year "no questions" warranty. Nest offers a two-year limited warranty unless it is put in by a certified installer, which gets you a five-year warranty.
How they learn
A major source of complaint from new learning thermostat owners concerns the learning part. If you want either thermostat to find the best temperature-to-affordability combination, it may take some trial and error. For a while, it may make you a little too hot or cold, and you will probably have to frequently readjust it. The Nest is more automated but may require more tweaking during the learning process. Ecobee requires more initial set up.
Nest will hold the first temperature you set until you change it. As you keep adjusting it over days, Nest begins to learn your routine. You do have the option of manually scheduling when to heat up and cool down if the Nest's adjusting drives you crazy. The Ecobee requires you to enter your schedule, then learns things like how much outdoor temperature affects indoor temperature, and how long it takes to heat or cool your house. Nest said it takes about 10 days to build a steady routine, where the Ecobee takes about 14 days.
Which one is right for you?
Which is right for you will depend on which smart thermostat smarts are most important to you. Google Nest shines when it comes to learning your schedule and is best in a home that doesn't need a lot of remote sensors—unless you like programming schedules. Ecobee is smarter about knowing which room it should make comfortable and when. If you have a lot of hot and cold spots, Ecobee will do more to even out your environment. Or you can just pick the one you find prettiest. Either will trounce your legacy programmable thermostat for comfort and savings.
Prices were accurate at the time of publication but may change over time.