Case Studies

Indoor Growroom HVAC System using Allen Bradley PLC, Ignition SCADA, BACnet/IP

Posted in Allen Bradley PLC, Energy and Utilities, HMI and SCADA, Manufacturing Automation and Intelligence


DMC worked with an indoor-farming company to provide rapid development and commissioning of control software for their HVAC system, including integrating with equipment over BACnet/IP and Modbus TCP/IP. This system was used to both maintain the building’s temperature and regulate the temperature and humidity of several grow room zones on a schedule of varying setpoints.


Our client was constructing a large grow room and needed a controls system to closely regulate the temperatures of its different zones. They sought out DMC because of our experience in HVAC system control and Allen-Bradley & Ignition programming. Further, our client was confident that DMC could complete the project in the required tight timeframe.

To maintain continuity with existing projects, DMC implemented the controls system using the client’s preferred architecture while making improvements to their blocks and style. The system included PID control loops to maintain setpoints of the many process variables such as flow, differential pressure, and temperature— as well as sequencing to ensure proper system start-up and switching between control modes.

The control system communicated with several OEM skids over Ethernet IP, BACnet, and Modbus. These skids included air handling units, chillers, boilers, and dehumidifiers. Each was integrated into the main process control as well.

DMC also developed an Ignition application with which operators could control the setpoints and parameters of the system based on a schedule received from a farm-wide server. Each skid had a custom screen where operators could monitor process variables and view the status of varying sub-systems. The SCADA collected data from over 100 sensors, which could be used to visualize the system's trends.

DMC was able to deliver a fully operational system by our client’s expected date, despite the tight timeline. They were extremely satisfied by the results and DMC has continued working with this client on commissioning a system using several remote IO modules controlled from a central PLC.

Learn more about DMC's Allen-Bradley PLC programming services and contact us for more information.

Customer Benefits

  • Rapid development
  • Onsite commissioning support
  • Simple Ignition interface
  • Robust control of setpoints
  • Energy optimizing control