College campus engineering: Challenges, retrofitting, renewable energy systems
Colleges and universities bear the important responsibility of molding the minds of future generations. To tackle the formidable task, such institutions require the expertise of engineers to ensure the complex buildings on campuses (laboratories, classrooms, computer centers) meet their needs.
- Michael Broge, Principal, Affiliated Engineers Inc., Madison, Wis.
- Joseph Lembo, PE, Partner, Kohler Ronan Consulting Engineers, Danbury, Conn.
- Rick Maniktala, PE, LEED AP, CxA, DBIA, HFDP, Principal/Vice President, M.E. Group, Overland Park, Kansas
CSE: What engineering challenges do colleges pose that are different from other structures?
Michael Broge: Colleges’ and universities’ capital and operational budgets are severely limited in today’s economic climate. Buildings are now almost always designed with the intention of being 50- to 100-year buildings and the energy efficiency of mechanical, electrical, plumbing (MEP), and fire protection systems is a priority. In many types of buildings, those systems are designed with significant flexibility to accommodate multiple reconfigurations over the course of those extended building lifespans. Preferences for low-maintenance system types reflect the reality of reduced maintenance budgets.
Joseph Lembo: Many of the higher education facilities that we deal with have aging central plants and infrastructure with minimal spare capacity. Designing for a major renovation or new building on such a campus requires extensive analysis on the existing central plant and how it is currently operating. Oftentimes a campus can go through a period in which several new and renovated facilities are constructed with no substantial plant upgrades. However, a point will come in which a single project will trigger a major campus infrastructure upgrade. We endorse the notion that higher education facilities allocate capital for infrastructure as a part of any major project. In doing so, this would avoid the burden of a single project absorbing the cost of upgrades.
Rick Maniktala: Engineers working on college campuses must understand the unique challenges their structures pose, the most significant of which is to understand the ways in which the structures are interconnected to one another across the campus, often sharing and/or hosting infrastructure services such as: chilled water, heating hot water or steam, fiber telecom services, electrical power transformers, water services, etc. The interconnection extends beyond infrastructure as they often serve as passageways with interior or below-grade corridors providing students with shelter as they travel across campus. There often isn’t good as-built documentation for the interconnections, so extensive field investigation is required.
CSE: How have the needs and characteristics of colleges changed in recent years?
Lembo: The American College and University Presidents’ Climate Commitment has driven many of the higher education facilities to place sustainability in the forefront of most new projects. We have found that it is critical to coordinate with the architect early on in the project to develop an envelope to help minimize the energy consumption of a building, prior to commencing schematic design. In-house energy simulation modeling has allowed our firm to analyze energy consumption early on and present this information to allow the owner and architect to make key decisions early on.
Maniktala: In recent years, colleges and universities have become increasingly competitive with building projects. They strive to maintain an advantage and attract students by improving the structures that support student life and their aspirations. New, innovative advanced degree programs are in demand and have been created while campuses race to offer these to students. Masters-level business programs with an emphasis on innovation and technology are in demand and have necessitated the expansion of degree programs and the construction of new buildings to support this growth.
Broge: Complexity has grown relative to systems, regulations, and project delivery. As the sustainable design movement has matured, many institutions have moved from self-certification of U.S. Green Building Council LEED-designed project to formal LEED application and certification. State governments have developed—or are developing—energy efficiency standards for public buildings that significantly exceed state energy codes. The emphasis on sustainability and energy efficiency often further complicates already complex building systems and controls, and many institutions are concerned about the related costs of maintaining these sophisticated technologies. College and university facilities management staff are much more involved in building design now than they were 10 years ago, reflecting a need to design to the “institutional maintenance culture.”
CSE: Many learning institution administrators are choosing to expand and remodel existing facilities rather than construct new buildings. What unique challenges do retrofitted buildings present that you don’t encounter on new structures?
Maniktala: Existing buildings on college campuses often have infrastructure services that are inefficient when compared to today’s standards. For example, an existing school of pharmacy building was converted to the school of architecture and urban planning. While the initial budget did not include the replacement of the existing constant volume dual duct air handlers with air cooled direct-expansion (DX) coils, the potential energy savings for doing so could not be ignored. Unsure whether the infrastructure upgrade could be afforded, the university elected to include an alternate design with total replacement of all the dual-duct air handling units (AHUs) to new single-duct variable air volume (VAV) units with hot water reheat terminals. The bids were favorable and the project moved forward with the modernization of the infrastructure AHUs, hydronic heating water system, campus chilled water tie-in, electrical service, etc. This example is not unique; many existing buildings on campuses across the country would benefit immediately from similar infrastructure upgrade/modernization projects to reduce energy consumption and improve thermal comfort and indoor air quality.
Broge: Older buildings’ structural elements—that is, columns, beams, and floor-to-floor heights—are generally fixed and extremely costly to modify, often presenting limitations to building programming and use. For example, the floor-to-floor heights of buildings predating current ventilation standards could either dictate additional vertical air distribution or simply spell obsolescence. Existing facades generally require upgrades with increased insulation, vapor barriers, and new window configurations, all of which may very well prove to be prohibitively costly to perform. Finally, renovations raise vital scheduling questions. A lack of significant available “swing space” to house large user groups during renovations will require phased renovations, relocating a sequence of smaller user groups. And phased renovation requires management of disruptions and inconveniences to adjacent users, including construction noise, dust, and periodic unplanned infrastructure outages.
Lembo: Existing buildings have aging infrastructure and envelopes that were built to earlier standards which were significantly less energy-efficient. Developing a plan of passive “envelope” and active “mechanical” approaches to not only improve energy efficiency but also incorporate sustainable design elements is important. This is where the collaborative design effort is required from all design team members.
CSE: What renewable energy systems have you specified on a college campus, and what were the results?
Broge: Colleges and universities are more likely to invest in certain renewable energy technologies than many client types. Systems using geothermal, solar hot water heating, and photovoltaic (PV) power generation technologies have become increasingly common in our project work. The effectiveness—and, thus, advisability—of these applied renewable technologies is largely dependent upon the geographic and climatic location of the project and the purpose for incorporation of the technology itself. For example, we designed a geothermal system as part of a building renovation at a larger public Midwestern university for the purpose of providing required environmental cooling after the central campus chilled water system was shut down for the winter. This application was successful in not only providing winter environmental cooling, but also providing nearly all of the building’s year-round heating and cooling energy. A less successful geothermal application was designed for a research building at another large public Midwestern university that requested the system for demonstration purposes. The complexity of this system has created challenges to balance the system’s thermal characteristics and to operate effectively. The use of PV technology in mass scale has been hindered in large part due to the high cost per installed watt—about $10/W a few years ago, though we have designed several “demonstration” projects corresponding to that number. Current installed PV costs are nearer $5/W due to improvements to the technology and greater familiarity with its installation. New building codes pertaining to PV are just coming into effect, and may impact installed cost.
Lembo: We have found institutional clients more receptive to innovative design strategies since many judge project merit based on intrinsic educational value and environmental impact rather than pure economics. Past successes for these clients include ground-source heat pumps (GSHPs) supplemented by solar evacuated tubes, passive outside air (OA) preconditioning via earth-ducts, and extensive use of PV. However, many colleges still find these types of systems impractical after weighing associated energy savings and environmental benefits against increased lifecycle costs. For a design to make it through the value engineering process intact, we have to leverage project-specific synergies and demonstrate tangible financial justification. In general, the majority of renewable energy installations benefit from grid parallel net metering. However, many utility providers preclude college campuses with distributed energy systems from participating in net metering contracts. Without the ability to use the grid as a battery, designing practical and financially justifiable on-site generation requires synchronizing energy production with energy demands. We have had success on several campus projects incorporating thermal energy storage (TES) to decrease losses from unused production and systematically control the release of energy to match HVAC loads—all while reducing installed chiller size. Recently our firm conducted an energy master plan for a college campus with a combined cycle power plant. General consensus prior to the study was that the campus needed additional capacity to meet energy demands. After extensive energy modeling and loads analysis, it was determined that TES could buffer demand shifts enough to capture an additional 30% of energy already being produced by the campus but not being used.
Maniktala: The Student Learning and Engagement Building at the Community College of Denver (CCD) will consolidate most of CCD’s administrative and teaching spaces into a single location. The 86,000-sq-ft project includes many high-performance features to enhance occupant performance, reduce energy consumption, and improve the student’s connection with the outdoors. These include natural ventilation strategies, radiant heating and cooling, active chilled beams, daylight harvesting, and advanced addressable lighting controls. A highly efficient chilled beam system will provide heating, cooling, and ventilation to the building. Combined with a simple boiler chiller plant, this design will reduce maintenance requirements, maximize energy efficiency, and offer flexibility for future renovations. By joining these advanced MEP design strategies with a building massing and envelope design that has been optimized through energy modeling, we anticipate that this project will use only 50% of the energy required for the baseline building. The project is targeting LEED Gold.
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