Yes, it is compatible with both 5 GHz and 2.4 GHz Wi-Fi connections; i.e. it is dual-band compatible. In choosing which Wi-Fi connection is best for your ecobee, it's important to note the differences between the two bands to make sure your ecobee SmartThermostat with voice control has the best possible Wi-Fi connection.
2.4 GHz band
The 2.4 GHz band has a longer range, which makes it ideal for devices that are placed further away from your router/access point. However, the 2.4 GHz has lower bandwidth which makes it slower than your 5 GHz Wi-Fi connection.
5 GHz band
The 5 GHz band has a much shorter range than the 2.4 GHz. However, it does have faster bandwidth to make up for its lack of reach. This band is ideal for data-intensive devices that are situated closer to the router/access point.
Setting up your device
Once you've chosen the ideal Wi-Fi connection for your SmartThermostat with voice control thermostat, follow the steps provided in our Wi-Fi setup guide and select the SSID or Wi-Fi name of the band you would like to connect to.
If your 2.4 GHz and 5 GHz Wi-Fi networks share the same name/SSID, the thermostat will pick the signal with the best strength to optimize Wi-Fi functionality.