Designing higher education facilities: Electrical and power systems
The world is getting more high-tech, and the colleges and universities preparing students to work in an increasingly advanced environment must keep pace. Electrical, power, and lighting systems are discussed.
- David P. Callan, PE, Vice President, McGuire Engineering, Chicago
- Michael Chow, PE, CxA, LEED AP BD+C, Member/Owner, Metro CD Engineering, LLC Powell, Ohio
- Essi Najafi, FE, Principal, Global Engineering Solutions, Bethesda, Md.
- Mike Walters, PE, LEED AP, Principal, Confluenc, Madison, Wis.
CSE: Describe some recent electrical/power system challenges you encountered when designing a new building or working in an existing building.
Najafi: In a recent existing building renovation, the existing ceiling heights were low and limited for housing the floor-mounted switchboards and equipment. We provided additional and specific directives for mounting the equipment as well as the methodology for the incoming and outgoing wiring method. In providing the new engineering systems for a 72,000-sq-ft, 40-year-old academic building at a local university, the design team was presented with the challenge of providing new telecom, audio-visual, electrical, and mechanical systems for one of the original buildings on campus. The building was slated for a total interior renovation while keeping the existing exterior skin and structural framing intact. The slab-to-slab height for this building was tight and the architect chose to have exposed beams and columns at corridors, making electrical/telecom distribution even more of a challenge. Working with the architect, we were able to successfully provide conduit and cable tray runs in architectural bulk heads and below slab runs while coordinating the new electrical work with mechanical, plumbing, and structural to provide a functional and aesthetically pleasing learning environment that the university could use for the next 40 years. The renovated building included more efficient lighting systems, a new electrical service with an established building ground, a new lightning protection system, as well as smart boards and HD projectors and LCD TVs at each teaching space to provide a flexible learning and teaching environment for the College of Education and Human Development.
Chow: Many colleges and universities do not have enough electrical capacity for a particular project. Many times budgets are established prior to the request for qualification/proposal where lack of available electrical capacity can present budget challenges and issues. Also, NFPA 70: National Electrical Code requires in certain instances to record the power consumption for a period of time. This monitoring may not have factored into the project's budget and schedule.
CSE: What low- and medium-voltage power challenges have you overcome?
Najafi: At a new 250,000-sq-ft arts building, the design team had to provide the electrical service for the building that tied into the existing dual fed medium-voltage campus loop. Given the building size and that this was the first new building on campus in more than 30 years, we provided a double-ended switchgear solution for increased reliability by using both feeds of the dual service loop system. In doing so we had to provide new manholes, service feeds, medium-voltage selector switches, dry type transformers, and low-voltage switchgear with tie-breaker in a back-to-back configuration lineup. Additionally, we provided a dedicated 750 kW diesel generator remotely located in a separate structure approximately 500 ft from the new electrical room to provide the life safety and standby power requirements of the new facility. Because of funding and overall master planning, the construction of the building was broken into two phases, the first of which consisted of 100,000 sq ft and the main MEP infrastructure and the second at 150,000 sq ft. The challenge was in planning, coordinating, and providing the design and construction services for the completed building with all systems functioning seamlessly.
CSE: What types of renewable energy systems have you recently specified in one of these projects?
Walters: College and university commitment to reducing greenhouse gas emissions has led to an increase in renewable energy projects. Our strategic energy projects have included a wide array of renewable energy projects for on-site generation including wind, solar, and fuel cell technology, while also looking to augment campus energy systems with cogeneration systems.
Najafi: We have specified a roof-mounted PV system to produce on-site renewable energy supplementing a building's electrical power. The size of the system was estimated at 168 kW dc with an energy output of 214.5 MWh per year. The system is designed to be installed at several different areas of the roof.
Chow: We designed a photovoltaic system for a major university that allows students to conduct research. The tilt-angle of the panels can be adjusted to measure efficiency at each angle versus time of year/day. Both monocrystalline and polycrystalline panels were installed. Local and remote monitoring allows research to be done to compare the efficiency of each technology. The PV panels are each monitored separately such that the change in any one panel can be researched and studied.
CSE: What unique lighting and daylighting requests have you fulfilled in recent college/university projects?
Najafi: In meeting local and state requirements for energy efficiency and LEED certification for a number of college and university projects, daylight harvesting and energy-efficient lighting with automatic controls have become more prevalent for these type projects. We have used the experience of our in-house lighting specialists on several projects to comply with the aforementioned requirements, which included automatic dimming of perimeter light fixtures, occupancy/vacancy sensor controls, and the use of LED lighting fixtures to provide an energy-efficient design while maintaining recommended lighting levels. In one recent project, special emphasis was placed on designing a daylight harvesting system in conjunction with automatic shade controls. Certain classrooms required five lighting preset mode controls, including dimming and shade controls. The system had the capacity to easily monitor, control, and optimize the lighting system from any tablet, PC, or smartphone. When we provided daylighting we considered each user/occupant's preferences. This request was accomplished by commissioning and adjusting the daylighting system in each space per occupant preferences and the availability of daylight.