College, university building automation and controls
College and university campus buildings have a lot going on—classes, research, dining, and sleeping. Building automation systems must be carefully specified to control the systems within these buildings.
Robert Garra, PE, CDT, Vice president, electrical engineering, Cannon Design, Buffalo, N.Y.
Randy Hassler, PE, LEED AP, Principal, McClure Engineering, St. Louis, MO
Andrew Slater, PE, Electrical engineer, HGA Architects and Engineers, Milwaukee, WI
CSE: What factors do you need to take into account when designing building automation systems (BAS) for colleges and universities?
Hassler: One key factor to having a successful energy management system is good service and knowledgeable technicians from your vendor(s). Alarms management, scheduling, what to trend, sample frequency, how long to keep it, and managing the data require different strategies on large campuses compared to a single building. If third-party software is used for integration, then programming is required by the integration vendor also and would need to be included in the project.
Slater: Understanding the needs from the campus is a critical step to ensuring a successful BAS system that will be used. BAS systems have several capabilities that offer control and monitoring to a multitude of building systems. Working with the client may only unveil that they may just want to schedule equipment and alert personnel to critical events. The end result would be a satisfied client that is able to generate financial savings.
CSE: How does implementing BAS in an existing building differ from designing controls for a new building?
Hassler: Understanding and following naming conventions is important so that that there is no overlap and duplication of names. It is very common for engineers to name the equipment “Equip”-1 (i.e., AHU-1, VAV-1, EF-1) for their project. If the building already has air handling units AHU-1 through AHU-4, then the next one should be AHU-5. It also is helpful to number the variable air volume (VAV) boxes with the air handling unit (AHU) number first followed by the VAV box number, in that case the first VAV box would be VAV 5-1 followed by VAV 5-2. Wireless devices and networks may be cost effective in existing buildings that can be more difficult to wire.
CSE: What types of energy management systems are you specifying on colleges and universities? Are these part of full-building control systems?
Hassler: We see a few different strategies that campuses use to purchase their energy management systems. Some have a sole source vendor, others will use two vendors that will competitively bid for new projects, and others use an open protocol strategy. Colleges that have not invested in a campus-wide system have older, stand-alone building controls or a mix of different vendors building by building as work was performed.
CSE: What new types of controls are you specifying into colleges and universities? Is the demand for personal control increasing?
Garra: Engineers are seeing a more pronounced role of advanced lighting control strategies, directly tied to high efficiency and reducing operating costs. Available solutions could include incorporating daylight harvesting, task tuning, load shedding, and personal controls, in addition to traditional time-based and occupancy controls. These advanced lighting control strategies are connected to a BAS to allow for device sharing between mechanical and lighting systems. For example, we can use room occupancy sensors to communicate with both the BAS and lighting controls to reduce energy in unoccupied spaces. The systems are incorporated with very user-friendly graphical interfaces for ease of operation. Electrical power management systems (EPMS) also allow campuses more proactive approaches to load consumption rather than reactive methods. This data can simply be accessed from a web-based platform. The system integration to a single platform is also gaining momentum on campuses. A single location that houses building management systems (BMS), lighting control, EPMS, or other systems is becoming a very attractive option.
Hassler: Typically everything has been direct digital control (DDC) for almost two decades. From time to time we have had an owner that still prefers pneumatic terminal unit control. Control zones at the personal level are strongly influenced by system type and vice versa. For example, fan coil unit systems lend themselves to individual control. For VAV systems, personal zone control is a matter of economics. We might see the request for personal control in private offices in the 30% range. For added personal control when three or four like spaces are grouped into a single zone, warm/cool sliders with a voting scheme can be utilized rather than a single thermostat.