energy costs rise, the need for advanced HVAC control becomes more important for households and businesses alike. We had the opportunity to review the new Ecobee Smart Si thermostat that includes a host of powerful features for users who want full control of their heating and cooling systems. The Smart Si thermostat has built-in WiFi (B/G/N) allowing complete control of your heating and air conditioning remotely as well as access to the current outdoor temperature and humidity. The design is simple on the surface with an easy to read backlit display, a set of navigation controls with Menu and Back buttons. The Smart Si thermostat runs from the standard 24VAC power used for the heating and cooling system. A backup battery is installed for keeping track of the data in the event of a power failure.
See how we use the Smart Si with our Solar System
Replacing your current thermostat is quite easy and Ecobee has a comprehensive Installation Manual making it a snap for do-it-yourselfers. However, if you are not comfortable with the installation, Ecobee highly recommends that you hire an experienced HVAC technician. If you connect to your equipment incorrectly, it is possible to damage your system. We found it useful to take a picture of our previous thermostat to identify the wiring for the new Ecobee Smart Si. Our system uses a single stage heat/cool interface that runs from 5-wires. In this case, the installation took just a few minutes. The wiring diagrams in the manual give excellent examples of various HVAC systems and how to connect them.
Cooling and Heating
Pressing the menu button on the Smart Si thermostat allows users to manually change the heating and cooling temperatures. Pressing the left button selects the cooling screen while the right button selects the cooling screen. The up and down arrows increase or decrease the temperature setting for the screen selected. The current temperature along with the relative humidity is also displayed. The date and time are shown at the top of the screen with the WiFi link status and signal strength.
Extensive Menu Options
Pressing the menu button will toggle between the heat/cool screen and the settings screen. Here the user can configure a whole host of options in the Smart Si thermostat. WiFi configuration as well as specific details about the way the system will work is completely adjustable by the user. Here are a few screens we captured for reference.
Users can login to Ecobee’s website and gain full access to their thermostat. In cases where multiple thermostats are installed at a location, Ecobee allows you to group them together if needed. The website has three main tabs (comfort, settings, and Home IQ™) and offers more features and control than is available through the iOS and Android devices. Users will need to register their thermostats to gain access.
The Comfort tab provides access to Program, Vacation, Weather, Ecobee News, and System Details. This is where most of the main activity will take place to control your thermostat settings. Users can enter in their vacation schedules to make sure that their heating and air conditioning is not running unnecessarily while no one is at home. This tab also provides real-time weather information for your location.
Using the programming panel, users can schedule four custom states that include Awake, Away, Home, and Sleep. These states each have a temperature range that can be defined by the user. This information determines the temperature control desired during the time of day and day of week. For example, during time the user is not home, it is most efficient to expand the temperature range to minimize the amount of time the heating and cooling activates. This range may not be desired if you happen to be at home, so additional states are available. At night, most users like it cooler and warmer first thing in the morning, so different temperature ranges can be defined for each. There is also a Quicksave mode that automatically moves the heat/cool temperatures +4 degrees for cooling and -4 degrees for heating. This is a great feature if you happen to be leaving the house for a while and do not want to waste energy. Users can always manually override the scheduled temperatures if needed.
The Settings tab provides access to My House, Preferences, Reminders, and Custom Messages. Custom Messages can be sent from the website to the display on the Ecobee thermostat. The Preferences screen contains all of the customizable settings (there are many) and also contains the access control settings for the thermostat. The Reminder screen lets you know (by email) when it's time to service your HVAC system (filters/lamps/etc.) as well as notify you of temperature or humidity (high/low) limits. This is also where the thermostat groups are managed.
Ecobee’s Home IQ™ provides a personalized profile of user's home heating and cooling performance, energy efficiency and savings. The Home IQ™ interface is easy to understand, navigate and control, making it easy to manage your home energy consumption. There are three different screens in the Home IQ™ tab called Home IQ Details, Home IQ Insights, and Reports.
Home IQ Details
The Home IQ Details screen provides a summary of the runtime for both heating and cooling. Data can be display hourly, daily or monthly with the selected year. The previous year is also displayed for comparison. It is a quick way to assess the amount of energy you are using in your home. The Weather Adjust Runtime tab shows the Runtime per Degree Day as an alternate way to see energy usage.
Home IQ Insights
The Home IQ Insights screen provides users with a comparison of their system against the average in their state. Users can see their monthly estimated energy savings, monthly heating and cooling summaries, and details on performance influencing factors such as the weather and average set point, HVAC runtime reports and more. In our case, we ran 92% less than the average in California for the month of April. Comparison from the previous month for both heating and cooling are provided. Heating and cooling set points are also compared to the previous month to help you better manage potential savings.
The Reports screen is one of my favorites with plots of the heat/cool set points plotted against the outside and inside temperature. Users can clearly see when their heater and air conditioning turned on and for how long. Users can download data (csv format) from the past 3 days, 1 month or 3 months. The file contains contains heat/cool set points and modes along with telemetry captured every 5 minutes. It's a comprehensive data file for those who would like to run their own data analysis.
iOS & Android Support
One of the best features offered on the Ecobee Smart Si thermostat is the ability to control your heating and air conditioning remotely. We ran the Ecobee app on four of our favorite devices (Samsung Galaxy Nexus, iPhone 4, iPad, and Nexus 7). Replacing your current thermostat is quite easy and Ecobee provides a comprehensive Installation.
The Smart Si thermostats can be controlled when you are away from home using their iPhone/iPod Touch or Android apps. Simply download the free app and login to access your thermostat. The user interface is simple and easy to use making it fast to change settings. Simply drag your finger across the temperature bar and the heating or cooling threshold can instantly be changed in your home. The software sends the temperature command and your display is updated based on the reading to verify the temperature has been properly set. This two-way communication is important in the event the setting does not make it through.
The Ecobee Smart Si thermostat is both affordable and easy to use. It does not require a subscription to operate the thermostat remotely, so there are no hidden fees. The apps that are available for both Android and iOS tablets and phones work flawlessly and it provides an easy way to manage your home's heating and cooling both at home and while away. The wireless interface worked perfectly in our house and we never had any issues controlling the device. The Ecobee website allows complete control of your thermostat settings and even allows groups of thermostats to be managed easily. We have been using our Smart Si for several months now and I can't imagine going back to my old thermostat. Ecobee did a great job designing the interface and the statistical data analysis software gives customers important information about their energy usage.
SCE Rebate for Install
Much to my surprise, SCE is currently offering a rebate for the Smart Thermostat and its installation. This totals $125, making the Ecobee Smart Si even more attractive. This pretty much makes it a no-brainer. Check the SCE website for current rebates.
The Ecobee Smart Si does so much to manage your home energy cost that it will pay for itself in little time. The street price for the unit is around $200 and is well worth it given the amount of features and overall reliability of the product. I love the display (although small) on this unit as it is easy to read with good contrast. The buttons have a nice tactile feel and are arranged logically for a simple user interface. This is one of the best engineered products we have reviewed in a long time.
Inside of the Smart Si thermostat is a socket designed for the installation of an optional Zigbee module. Zigbee is a low-bandwidth, two-way wireless communications protocol based on IEEE 802.15. s
Installation is easy by simply attaching the Zigbee module connector and plastic stand-off to the main unit. The installation does require the latest firmware update to be loaded in the Smart Si to compensate for the slight increase in internal temperature since the Zigbee module sits just above the internal temperature sensor. The new Zigbee module gives the Smart Si additional capabilities that include full two-way communications with the new Ecobee Smart Plug modules.
Ecobee Smart Plugs
Smart Plug modules can be controlled remotely or on a predetermined schedule to help manage your energy use. The power consumption of the device connected to the smart plug is monitored and is available at the Ecobee website. Ecobee manufactures their Smart Plugs to give customers a better way to understand, manage, and reduce energy use. Simply add a Smart Plug to your ecobee Smart Si thermostat and you will be able to take full control of your connected appliance through your existing ecobee Web Portal.
Smart Meter Compatible
Another alternative use for the Zigbee module installed in the Smart Si thermostat is connecting it to your smart meter. We have an SCE (Southern California Edison) smart meter in our house that include a wireless Zigbee interface. Connecting the the Ecobee Smart Si thermostat to the smart meter does require the user to register the Zigbee information with SCE. The Zigbee module (from Ecobee) includes a sticker that provides the 64-bit MAC address and Installation Code required for registration at the SCE website. Once this information is entered, the smart meter will try to link to the Smart Si thermostat. It is important that the user enables the smart meter installation mode on the Smart Si so that the smart meter can properly pair with it. It is similar to pairing Bluetooth devices. Once the smart meter pairs with the Smart Si, a message will be displayed on the thermostat as well as an email sent to the user.
Near Real-time Data
Once the Zigbee link has been established, the user can log into the Ecobee website and click on the Home IQ tab where hourly, daily and weekly power usage is displayed. The main difference between the SCE website information and the Ecobee (real-time) information is the data is displayed almost immediatly rather then having to wait a day or more using the SCE website. In addition, the Ecobee power data is logged every 5 minutes and is available for download (CSV file) for post-processing such as graphing and trending.