As elements of our lives become increasingly reliant on the Internet of Things, millions of homeowners and renters are installing “smart thermostats” to manage their energy costs.
Generally speaking, a smart thermostat uses digital components to automatically adjust temperature settings and other functions to maintain conditions that you establish. The majority of these systems work with your home wireless network and allow you to remotely adjust the controls through an app on your phone. Many also integrate with virtual assistants like Amazon’s Echo and Google’s Home, providing voice control over your thermostat as well as additional cues for adjusting settings (such as turning the air conditioning on when you unlock your front door).
Why Should I Get a Smart Thermostat?
If you travel frequently, juggle a busy family schedule or simply want to use energy more efficiently, a smart thermostat is a good investment. You’ll have the flexibility to remotely control the climate in your home, and eventually, the thermostat will “learn” your family’s schedule and habits and start to regulate itself—for example, adjusting the temperature when no one is at home or heating and cooling only the rooms being used.
In addition to maintaining the comfort level of your home, a smart thermostat can significantly reduce your energy costs—some systems claim to pay for themselves after just a few years of use—and soften your impact on the environment. Research conducted by energy efficiency rating company Energy Star indicates that installing smart thermostats in every household in the U.S. would generate a cost savings of more than $740 million per year and eliminate 13 billion pounds of greenhouse gas emissions annually.
What Should I Look for in a Smart Thermostat?
As demand for smart thermostats has skyrocketed, the options available on the market now number in the dozens. As you comparison shop, look for a model that hits the following marks:
- Optimizes your comfort level and energy efficiency (via algorithms, geofencing or other smart features) without requiring you to make manual adjustments
- Noticeably reduces your energy consumption and costs; be sure to find out if your utility provider offers rebates or other discounts for using an Energy Star-certified device
- Is intuitive to use, both at home and remotely
- Integrates seamlessly with other smart home systems and virtual assistants
- Tracks your energy use patterns and offers feedback to help you adjust and become more efficient
As far as cost goes, most smart thermostats fall somewhere in the range of $130 to $250. Paying less means you’ll get limited features, while thermostats above that range will probably include bells and whistles you don’t really need.
Which Smart Thermostat Models Are the Best?
The reviews below consider some of the most popular smart thermostats in eight main categories:
- Design (appearance and ease of use)
- Compatibility with common HVAC systems
- Installation and setup
- Smartphone app functionality
- Integration with other smart home systems
- Energy-use data and recommendations
- Additional features
Since the release of its first-generation smart thermostat in 2011, Nest has dominated the category, earning two of the top spots on our list with innovative features and reliable performance. The Nest E is the value-priced version of the original Nest, delivering the same intuitive interface and smart features as its costlier counterpart in a compact, affordable package.
Installing the Nest E is a snap. The only tools you’ll need are a screwdriver and your Wi-Fi password. Once you attach the baseplate to the wall and connect the wiring, the device will walk you through the setup process. According to the company, neither the original Nest nor the E requires a C wire for operation with the vast majority of HVAC systems. The device will ask you to select “eco temperatures” (the energy-saving default for when no one is home) as well as “home temperatures” (the range of temperatures to keep the house comfortable when occupied). Connecting to Wi-Fi is optional, but doing so unlocks a wealth of functionality, including the use of the Nest smartphone app, which includes geofencing and integration with other smart home devices.
The E is designed to learn and adapt to your preferences based on any adjustments you make, so after about a week of use, it should be able to anticipate your family’s schedule and energy needs. Embedded sensors that detect temperature, humidity, occupancy and ambient light help further refine its operations for maximum efficiency. You can also install up to six additional Nest Temperature Sensors, which are placed in various rooms to establish alternate settings for the thermostat.
Aesthetically, the Nest E is designed to blend into most home décor, with a clean white casing and frosted plastic face. An outer ring allows you to adjust the temperature and scroll through on-screen menus. As you approach the unit, the display “wakes up” to show both the set and actual temperature. Press the screen to go to a menu that allows you to change the mode, update settings, turn on the fan and view the date, time and weather.
The Nest mobile app allows you to view the schedule the system has developed, adjust it as needed and see your energy use statistics over the past 10 days. The app also taps into the Home/Away Assist feature, which uses geofencing to determine whether to go into Eco mode.
Other key features of the Nest E include:
- Algorithms that allow the unit to learn how quickly your home heats and cools and how well your HVAC system performs, which it combines with local weather data to help it determine optimal settings
- In-app alerts that let you know when it’s time to change your air filters or perform other needed maintenance on your HVAC system
- Integration with a wide range of smart home devices and systems, including Alexa, Google Assistant, Vivant, Control4, Wink, Lutron, Insteon and WeMo (although surprisingly, it doesn’t work with Apple’s HomeKit or Samsung’s SmartThings)
- Excellent performance
- Easy-to-use mobile app
- Integration with Alexa, Google Assistant and other smart home systems
- Energy Star rated
- System screen resolution isn’t as sharp or brilliant as many competitors
- No integration with Apple HomeKit or Samsung SmartThings
Now in its third generation, the Nest Learning Thermostat includes all the features and functionality of the E, but with additional options for complex HVAC systems and a sleek profile.
The first difference you’ll notice between the Nest and its economy-priced counterpart is the design. It features a striking black face and metal ring for adjusting settings, and its high-resolution display delivers crisp colors and easy-to-read text. Unlike the Nest E, which tends to blend into its surroundings, the Nest was made to be seen.
One feature of the Nest that’s missing from the E model is a feature dubbed “Farsight,” which senses your presence from a greater distance and lights up the display so you can check the temperature without being right in front of the unit. Farsight also allows for customization of the display when not in use; options include temperature, weather or time (with digital or analog clock faces). The display’s color turns red when in heating mode and blue for cooling mode, providing additional information about system operations from a distance. The third-gen Nest also includes a convenient magnetic screwdriver to assist with installation.
Beyond that, the Nest and Nest E are virtually the same unit, with similar learning abilities and compatibility with other smart home systems and Nest Temperature Sensors.
- Striking design
- High-resolution display
- Farsight feature
- Energy Star rated
- Lack of compatibility with Apple HomeKit and Samsung SmartThings
If you’re looking for the smart thermostat that does it all, the Ecobee4 is your solution. The fourth-generation model from this respected Canadian company offers users ultimate control over their energy use along with seamless integration into your existing smart home systems.
The Ecobee4 includes an impressive list of features that the Nest units lack, such as:
- High-functioning remote sensors that use motion and other feedback to manage two or more areas in one climate “zone”
- Built-in Amazon Alexa smart speaker
- Compatibility with all major smart home systems, including HomeKit, Alexa, Google Assistant, SmartThings and Wink
- HomeIQ, which collects comprehensive household energy use data, including real-time updates and usage history
The design aesthetic of the Ecobee4 diverges somewhat from the round shape of the Nest units; the sleek black box with rounded corners resembles a smartphone app and is about twice the size of the Nest E, in part due to the integrated Alexa speaker. In contrast to the Nest’s dial-based adjustment tool, the Ecobee4 relies entirely on a touch-screen display, which feels more natural to users accustomed to being on their smartphones all day.
Installation of the Ecobee4 is decidedly more complicated than Nest setup, primarily due to the complexity of its features. It does require the use of a C wire but includes a power-extender kit and instructions for connecting it to your HVAC system.
You can manage your Ecobee4 settings in several ways:
- Integrated and remote sensors, which use temperature and occupancy data to set heating and cooling schedules
- Customized sleep, home and away schedules
- Geofencing using the mobile app
- Ecobee’s Alexa Skill, Ecobee Plus
Ecobee’s remote-sensor capabilities are perhaps its greatest selling point, as they more accurately read and adjust the temperature in multiple rooms, a feature that’s especially useful if you have an older home that doesn’t heat and cool evenly. One sensor comes with the thermostat, but you can add as many as 32 additional sensors for precise tracking in every nook and cranny.
- Compatible with all major smart home systems
- Built-in Alexa speaker
- Comprehensive energy usage reports and fine-tuning capabilities deliver maximum control
- Significant learning curve
- Requires a C wire, which may make installation more complicated
At just $150, Honeywell’s Lyric T5 is the most affordable model to rank on our list. While it lacks some of the functionality of more expensive thermostats, it still delivers comparable features—including smart scheduling, geofencing and compatibility with most smart home systems—at a bargain price.
The Lyric T5 is visually attractive, though larger than most of its peers. The obsidian-black face provides striking contrast with its white text, and the display defaults to time and current temperature readings until it’s touch-activated by the user.
The installation process is fairly basic, although the Lyric T5 does require a C wire to function. The device guides you through setup, prompting you to establish temperature settings for Home, Away, Wake Up and Sleep, as well as the option to enable geofencing. You’ll need to download the Lyric mobile app to connect the device to your Wi-Fi network and pair it with HomeKit, if desired. The app is also the easiest way to set and adjust your schedule.
If you opt to enable geofencing, the Lyric T5 manages your home’s climate using the location of your smartphone (as well as the phones of other members of your household). This location information is paired with the time of day to establish Home, Away and Sleep temperatures. However, if you prefer to use a schedule you establish, you’ll need to leave geofencing turned off.
One feature unique to the Lyric T5 is Auto Changeover, which allows the thermostat to determine when to move into Auto mode, where the unit switches automatically between heating and cooling functions. All the other models we reviewed require the user to manually activate Auto mode, but the Lyric T5 does it for you, allowing it to maintain your established settings regardless of the weather.
- Affordable price
- Attractive unit
- Compatible with Apple HomeKit and Amazon Alexa
- Requires C wire
- Doesn’t provide energy usage data
While these thermostats didn’t test as well as the previous models on our list, they still offer a solid mix of features and functionality and may be a good fit for your household needs.
- Compatible with Microsoft’s Cortana virtual assistant
- Tracks indoor and outdoor air quality
- Unique design
- Changeable cover offers multiple color options
- Works with Amazon Alexa, Apple Home Kit and Google Assistant
- Smart scheduling feature includes utility cost estimator
Smart thermostats offer users valuable control over their energy use and the convenience of managing their home climates from anywhere. Depending on your desired level of functionality and special features, you’ll probably spend somewhere between $150 and $250 for a quality model—an investment that’s well worth making given the savings you can achieve on your monthly utility bill.