www. refrigerationandaircon. co. za RACA Journal I May 2025 5
Associations
LonWorks, BACnet and Modbus. These protocols facilitate communication between HVAC controllers and devices, and any errors in programming can lead to system failures or inefficiencies.
• Modbus: A common open-source protocol used in industrial automation that enables devices to communicate over serial connections or TCP / IP.
• LonWorks: An open standard that supports communication over different media, such as power lines and wireless networks, providing flexibility for building control systems.
• BACnet: A widely adopted protocol in building automation, BACnet enables devices from different manufacturers to work together. It supports both traditional serial connections and modern IP-based networks( BACnet IP).
Fox highlights BACnet IP as the most modern and secure version of BACnet, offering scalability and enhanced remote control capabilities compared to older versions of BACnet.
INTEGRATING HVAC CONTROLLERS WITH BAC0 One of the more technical aspects of the talk centred on integrating HVAC controllers with BAC0. BAC0 is a Python library designed to interact with BACnet devices, enabling HVAC professionals to control and monitor devices remotely. The library is based on an underlying package called Backpipes, developed by Joel Bender, and was initially created to make testing BACnet devices more accessible.
With BACO, HVAC engineers can send commands to BACnet devices, read their data, and troubleshoot issues before deployment. It provides a user-friendly method for interacting with BACnet devices and ensuring the system functions as expected. Another tool introduced was YABE( Yet Another BACnet Explorer), which provides a graphical interface for visualising and exploring BACnet networks, making it easier for engineers to understand the structure of devices and data on the network.
REAL-WORLD APPLICATION VIA CASE STUDY To showcase the practical applications of these tools, Fox shared a case study where he and his team tackled a client’ s challenge of displaying temperature and humidity data on large screens. The client had specific requirements, including the need to display this data on two large screens located 40m apart. The challenge arose because the existing system only supported small screens and proprietary output signals, making HDMI connections over long distances unfeasible.
Fox’ s solution involved integrating a standalone controller that communicated with the Environmental Monitoring System( EMS) via BACnet. The team also implemented HDMI
over Ethernet, which allowed the signal to travel over longer distances without degradation. A custom Python application was developed to interface with the BACnet controller, manage the data and display it on large screens. Key programming tasks included defining specific data points, setting up communication properties, and ensuring the system handled errors gracefully. The result was a stable and reliable system that met the client’ s needs, demonstrating the power of Python and BAC0 in solving real-world HVAC challenges.
LEARNING HVAC CONTROLS PROGRAMMING Fox closes the talk by offering insights into how aspiring HVAC professionals can start learning HVAC controls programming. He outlined several pathways:
• Formal training: Many companies offer structured training programmes through controls providers, though these often come with a cost.
• Self-study: For those just starting, self-study via online tutorials can be a cost-effective way to learn, though the quality of resources can vary.
• Colleges and bootcamps: Some colleges and coding bootcamps offer specialised programmes focused on HVAC control programming, which provide a more in-depth understanding of coding concepts.
• Foundational knowledge: Regardless of the path taken, Fox emphasisesd the importance of building a strong foundation in programming concepts, especially for those new to the field.
FINAL THOUGHTS ON STRIKING THE BALANCE Fox concludes by reaffirming that both proprietary and open-source solutions have their place in HVAC systems. While proprietary systems offer reliability, support and industry compliance, open-source solutions allow for greater customisation and flexibility. The choice between the two depends on the specific requirements of each project, including regulatory concerns, complexity, and liability risks.
For those interested in programming, Fox encourages experimentation, stressing that the learning journey can involve some trial and error. The key takeaway is that both approaches— proprietary and open-source— have their advantages and challenges, and HVAC professionals should carefully evaluate which is best suited to their needs. Ultimately, both paths offer opportunities for growth and innovation in the HVAC industry. RACA
“ The result was a stable and reliable system that met the client’ s needs, demonstrating the power of Python and BAC0 in solving real-world HVAC challenges.”
www. refrigerationandaircon. co. za RACA Journal I May 2025 5