System Operation and Control Sequence
The main control loop is located in MainController.java. This class has one method that handles some setup matters such as initializing the zones, then loops forever to complete the control sequence. Each zone is responsible for calculating how many stages of heating or cooling it needs to reach the temperature setpoint the user controls from the interface (see https://github.com/lbrombach/OpenHVACControl/wiki/Zone-Logic-Sequence), and the controller then checks the requests from all zones to decide whether to set the system to heating, cooling, off, or run only the fan for circulation. The controller prioritizes calls for heat - only if there are no zones requesting heat does the controller check if any zones are requesting cooling. Only if no zones are requesting cooling does the controller check if any zones are requesting fan-only operation. When turning off heating or cooling either due to reaching setpoint or user turn the mode to "OFF" , there is a delay of about a minute to ensure the system has time to cool down before closing dampers or processing a new request.
