The "PowerTail AC" project is a browser-controlled thermostat for use with window ACs. It's a big switch with a thermometer, and can be used with most electrical appliances.
The PowerTailAC project was the perfect testbed for refining the IoT communication stack, and updates to the project often trickled down to the Train Automation project.
The device sits directly underneath the AC and in between the power chord and the outlet. The temperature sensor requires constant airflow for accurate readings so a USB fan provides this when the AC is off.
Temperature, humidity, power state, set point, mode (auto/manual) are transmitted by the device to the hub.
Power shuts off at -2F° of the set point and re-starts power at +2F° when in auto mode.
A safety timer that prevents re-starting power before three minutes in all modes.