Constructing college, university buildings wisely: HVAC
Engineering mechanical, electrical, plumbing (MEP), and fire protection systems in colleges and universities requires designers to look toward the future of postsecondary education, and consider all aspects of a building and its occupants. When designing HVAC systems, mechanical engineers have several options to consider.
Aravind Batra, PE, LC, LEED AP, Principal, P2S Engineering Inc., Long Beach, Calif.
Craig Buck, PE, LEED AP, Associate, RMF Engineering, Charleston, S.C.
Jeffrey R. Crawford, PE, LEED AP, CCS, Vice President, Director of Higher Education & Research Market, Ross & Baruzzini Inc., St. Louis
Andre M. Hebert, PE, BEMP, LEED AP BD+C, Principal, Senior Mechanical Engineer, EYP Architecture & Engineering, Boston
Sergiu Pelau, PE, LEED AP, Principal, Syska Hennessy Group, New York City
Scott Robbins, PE, CEM, LEED AP BD+C, Senior Vice President, WSP | Parsons Brinckerhoff, Boston
CSE: What unique HVAC requirements do college/university projects have that you wouldn't encounter in other buildings?
Robbins: Colleges/universities are unique in that they have almost every building type under their responsibility. They need to understand and maintain all these buildings—laboratories, libraries, residence halls, classrooms, athletic arenas, dining facilities, hospitals, and offices. As designers, we need to understand the uniqueness of these buildings and provide designs that meet university requirements.
Buck: From an HVAC perspective, system flexibility and control is a challenge that we face working with universities that we don't see with other owners. Many times these facilities are going to be renovated in 5 or 10 yr, and the program of the space may change drastically. This means that the infrastructure needs the flexibility to meet a variety of needs with a minimal amount of renovation.
Batra: Unique HVAC requirements in college/university include 24-hr operation for research facilities, offpeak and weekend operations, outside-air requirements, and higher air-change requirements for lab facilities.
CSE: What changes in fans, variable frequency drives (VFD), and other related equipment have you experienced?
Hebert: The single biggest shift we have seen is the near-total adoption of direct-drive fans in lieu of belt-driven fans for many HVAC applications. The drive losses and maintenance costs associated with belt drives are generally a thing of the past. Additionally, the direct-drive fan packages have the added benefit of being more compact, thereby enabling a more modular approach to air-handling unit (AHU) fan section design. It is now very common to see fan arrays replacing the large base-mounted fans in AHUs. This movement has in large part been made possible by the advances in VFD technology and the resulting decrease in VFD size and cost.
Batra: Changes have included fan-wall and smaller electronically commutated motor-type fans that have plastic housing/blades and harmonic reduction, surge suppression, and improved reliability in VFDs.
Buck: All of these technologies have become more efficient and reliable. The introduction of the fan array, for both redundancy and energy efficiency, has been the biggest change in fan technology. Also, the improvements in all equipment with regard to space acoustics have created environments that are more conducive to learning, which is critical to successful buildings at colleges and universities.
Robbins: Almost every pump and fan system we design are provided with VFDs. Their cost and reliability have improved to the point where they make sense versus motor starters. Even with constant-volume systems, we use the VFD to balance the system versus a circuit-setter, which saves energy.