Better connected building automation systems with BACnet: Five examples
Jason Gerke and Yanlin Zeng discuss the importance of BACnet alarms and analytics and provide examples of connected facilities
- Understand key equipment for integration options to improve system efficiency.
- Review examples of designing control systems for HVAC systems.
- Additional audience questions are answered.
- Analytics systems in building automation can help predict and prevent equipment failures.
- Integration of systems using BACnet protocol allows different components and devices such as HVAC, lighting, security and water filtration systems to work together seamlessly.
These five examples of connected building automation systems (BAS) is from a March 2023 webcast, “HVAC and BAS: Can BACnet control an HVAC system?.” The full webcast can be accessed webcast here.
- Jason Gerke, PE, LEED AP BD+C, CxA, principal, GRAEF, Miwuakee, WI
- Yanlin Zeng, PE, CEM, CMVP, LEED BD+C, Controls Engineering Supervisor, Southland Industries, Dulles, VA
Office and manufacturing facility integration
Jason Gerke: The first example is a nice big building. It’s a large office and manufacturing facility located in Milwaukee, Wisconsin. The manufacturing building is used to create large assemblies for mining equipment and it includes many production machines, machine tools, lighting, security, gas systems and heating, ventilation and air conditioning (HVAC). One of the early project goals included integration of these systems to achieve a specific purpose of overall energy reduction.
It was a very energy-intensive manufacturing environment. The facility uses over 17 megawatts of power, so any small percentage reduction in power consumption can be impactful. The design team established a concept and named it Skynet, in reference to the Terminator movies, as an artificial intelligence system. The system was conceived as a sphere with all systems plugging into it.
This arrangement aligned with the BACnet concept of the client-server architecture. The system arrangement allowed for data from one system to be shared with a central source to other systems and other devices with the primary purpose of data access and then of identifying methodologies for reducing the instantaneous energy consumption. This could mean shutting down equipment or limiting loads on various pieces of equipment that are different systems throughout the building.
The unfortunate thing is the system wasn’t included in the final project, but the excitement and the concepts that were discussed amongst the design team created some inspiration that extended to other projects to create some interrelated systems.
Water park control systems
Jason Gerke: Water parks are exciting in the fact that they’re interesting attractions, heavy architectural theming and have a lot of systems that would be really great if they could be programmed to work together. These facilities have HVAC requirements that will lead directly to positive customer outcomes.
In the Milwaukee area, there was an aquatic facility that had significant indoor air issues during a state competition. Fans and athletes complained of sore eyes and difficulty breathing. It turned out these issues were reportedly a failure in a piece of HVAC equipment. While the system component failure most likely did create an alarm, the control system that could have included analytics might have identified the issue ahead of time. It could have used air quality sensors, energy consumption meters or some other means. Implementation of a BACnet control system with the standard protocol would have allowed the sensors from these systems to work together to identify the issue.
Water parks not only include HVAC but also an aquatic management system. This aquatic system is established so that the various components are able to work together for water filtration, disinfection, rides and water features. A big back-of-house system is hidden away. These systems will include pieces like filters, pumps, variable frequency drives, chemical controllers, ultraviolet systems and flow meters.
Many times, these systems stand independently. However, integration of these systems on a single network that allows connectivity and communication across an automation system provides a great solution for these things to all work together. All of these systems have different controller types, whether they’re hardwired or they receive binary or analog signals, they can be integrated devices that work independently or with others. BACnet provides a great opportunity for these devices to all be put together on one system, viewed from a single location and able to react to the settings of other parts of the system.
Chiller isolation valve analytics
Yanlin Zeng: Let’s say there’s a chiller isolation valve being in position for several years. The analytics tools use the historical data to do the analysis and then based on how often the frequency that the valve drive opens or closes; it will give you a prediction.
In this example, the valve most likely will fail in two months. This way, the facility operator can order the valve ahead of time and then when the valve arrives you can schedule the technician and then schedule your chiller shutdown. This way, it really reduces the chiller downtime because without the analytics, suddenly one day there’s a chiller isolation valve failure. Then, the chiller has to be shut down.
Data center integration
Yanlin Zeng: This project example is for a confidential data center. There’s a 38-acre campus, and there are multiple buildings on the campus that provide 36 megawatts of power. Working on the data center job is very stressful, but with the COVID, there was another level of challenge. There were 28 cry units for each quad and it has to be finished in a very short time. There was no time to install all control devices when the units were delivered on-site, so the only option is to send all the control devices to the factory for installation.
Then there’s the question of how verify the installation is correct and how to do point to point checkout. Due to the pandemic, there was no travel allowed for in-person and factory witness test. The team worked together and created a solution doing virtual factory witness test.
Figure 1 shows the kit put together. There’s a cradle point, a T, a controller and a transformer that can be sent to the factory. Once factory received it and connected to the internet, and the technician can connect to the controller and start command, for instance, the fan to run. He can verify the fan status just from his desk.
With a video call, the technician shared his screen, so everyone can see. He commands the fan to run or the valve to open and verify the status on his screen. At the same time, the factory technician has an extra camera also showing on the screen. So, the technician took the camera with him to show everyone, “Hey, the fan is spinning and the valve is really open.” This allowed the team to do a virtual factory witness test.
Health science research facility integration
Yenlin Zeng: Another example is a health science research facility at University of Maryland. This building is 439,000 square feet. There are two level basements, two level penthouses and 10 floors including floor spaces like classrooms, conference rooms, labs and offices. There are three chillers, and cooling towers. There are lab unit (HU), Vivarium HU and office HU. There are over 1,100 terminal units. There are tube beams and fin tube radiators. There are steam generators, all kinds of equipment.
The team did some integration for the lighting system, fuel-oil system, fire alarm and their switchgear generator. There were challenges for this product from beginning to the end.
For example, the design engineer specified used spring return actuators on all the control valves including the 10- or 12-inch butterfly valves. Unless they go with pneumatic, there’s no such actuator available. So, there needs to be a lot of research to write a report to show the engineer. The only screw return actuator available up to 5 or 6 inches. Tried to convince to change the specification. But overall, this project’s very successful. The owner at the end is very happy with what they got and the general contractor observed what we provided, what we achieved.