Case Study: Consulting Engineering

Belknap Academic Building

University of LouisvilleLouisville, Kentucky

Bringing Innovation and Urban Higher Education Together

Located in the heart of the University of Louisville, the Belknap Academic Building is a focal point for student academics and sets a new benchmark for college campuses. Encompassing 169,420 SF, the 21st-century building offers engaging study and lounge spaces, state-of-the-art classrooms, and a dedicated science laboratory floor—all while prioritizing sustainability and occupant health and wellness. CMTA was hired to provide MEP engineering, sustainability consulting, and technology services for this impressive facility.

The Challenges

  • Maximize building energy efficiency while providing traditional central VAV systems connected to central chilled water and steam system to ensure ease of maintenance and system familiarity
  • Prioritize occupant health and wellness
  • Achieve LEED Gold Certification while adhering to budget and system requirements
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This project…provides state-of-the-art space for our students to learn, to engage their professors and to relax and catch up with their friends. In addition to the services offered in this building—tutoring, mentoring, and advising—will help ensure our students are on the path to success. Created with Sketch.

Dr. Neeli Bendapudi

Former University of Louisville President

The Solutions

The Belknap Academic Building replaced a 1963 facility that, after 50+ years, no longer served the needs of the University. Selecting this site made efficient use of limited space on an urban campus. The promenade in front of the new building was designed to support organic student flow to and from this new, high-profile campus focal point. Ample windows on all sides create a powerful visual statement and energize building occupants with connectivity to the outdoor environment and active campus life.

A crucial design challenge was maximizing building energy efficiency while providing traditional central VAV systems connected to central chilled water and steam to ensure ease of maintenance and system familiarity. The University of Louisville facilities team was closely involved in the HVAC system selection. As with many campuses across the country, variable air volume (VAV) systems gained popularity during the 1970s energy crisis and have become the preferred system type for servicing. In order for the building to perform well over time, facilities teams must be able to maintain and operate the building as designed. Subsequently, CMTA provided consistency of systems and equipment, while leveraging the systems innovatively to achieve sustainability goals that are maintainable over the life of the building.

To achieve these goals, the project used multiple energy efficient strategies such as energy recovery, dedicated OA for first-stage cooling, roof photovoltaic (PV) array, and dynamic glazing that adjusts tint level in response to the sun. The design team also worked collaboratively to ensure an efficient, tight building envelope. Collectively, these measures contributed to a significant reduction of HVAC system block loads. The baseline model for a facility of this type is 127.9 kBTU/SF/yr. Using actual metered energy use, the building is performing at an EUI of 59 kBTU/SF/yr, for an overall reduction of ~54% below a code-compliant design. When incorporating rooftop solar photovoltaics, the EUI is further reduced to an impressive 54.2 kBTU/SF/yr.

CMTA also incorporated several energy efficient design measures into the building systems. The dedicated outdoor air system (DOAS) includes total energy recovery, with 68% summer effectiveness and 72% winter effectiveness. Zone OA VAV terminals use CO2 sensors to control ventilation in response to actual occupancy. When spaces are unoccupied, occupancy sensors are used to turn off lighting, reset space temperature (+/- 3°F), and reduce OA ventilation to minimum airflow. During “occupied mode,” OVAV terminals provide a minimum airflow to continuously flush the space. A complete building flush was performed prior to occupancy for the LEED Indoor Air Quality Assessment.

Occupancy sensors within the lab spaces also ensure minimum air change (ACH) rates during occupied periods. Chemistry labs receive six ACH, equating to one air change every ten minutes, while Biology labs receive four ACH, equating to one air change every 15 minutes. Fume hoods maintain a constant 100 FPM face velocity to protect students from contaminants in the hood—in opposition to the trend of reducing face velocity to increase energy savings. In an environment with inexperienced users, a 100 FPM face velocity and hood automatic sash closers ensure the highest level of capture, containment, and overall safety, as chemical reactions or toxic vapors occur under the hood.

The HVAC design assumed low activity and space temperatures of 72°F +/-2°F in the summer and 68°F +/-2°F in the winter. Thermal comfort within high-volume, high-glazing spaces is improved with radiant floor heat in the winter. In the summer, thermal comfort is improved through dynamic glazing, reducing solar heat gain and glare. These energy efficient measures serve to create wellness synergy by providing quality daylighting, controlling glare, maintaining views, and contributing to occupant circadian rhythm.

Data-Driven HVAC Design & Implementation

High-efficiency condensing hot water boilers are typically used on campuses for summer reheat (approximately 6 months of the year), while steam-to-hot water heat exchangers are used during the winter months. To further drive energy savings, the two boilers—sized at 3,000 MBH—were piped in series with the steam heat exchanger (HX) to preheat the hot water return before entering the HX. The summer boiler was designed and modeled for year-round usage, providing heating over 95% of the year with steam for redundancy. However, while the energy data summary indicated that the EUI goal would be exceeded, further analysis indicated that the boiler was not operating as expected as the first stage of heating. The actual steam metered data was 19.4 EUI, at 60% efficiency, with the condensing boilers at 1.8 EUI with 97% efficiency. By ensuring the boilers are preheating, the overall building EUI is reduced by 7 kBTU/SF.

The Results

The cost shifting and design decisions implemented on this project made it possible to achieve a high-performance building within the existing construction budget. The most significant contribution was from the enhanced envelope, coupled with energy recovery strategies and an understanding of the building’s diversity. From a code compliant 127.9 EUI to a realized 59 EUI, this project saves ~$115,000 annually, or ~$5,750,000 over the building’s 50-year anticipated lifespan.

The Belknap Academic Building was holistically designed to have a minimal environmental impact, with accomplishments in water conservation, site integration, and a reduced carbon footprint. Energy reduction strategies contributed to ~2,500 tons of CO2 avoidance, and the block cooling load was reduced by ~230 tons—the equivalent of a centrifugal chiller with 550 pounds of refrigerant in the central plant. Additionally, indoor water use was reduced by 36%. Condensate drainage from penthouse AHU/DOAS cooling coils, estimated at 650 gallons per day peak, was reclaimed to a stormwater retention system. A large, roof-mounted photovoltaic array offsets over 8% of electrical grid energy use. Strategic site selection also minimized green space disturbance and enhanced connectivity. CMTA was proud to partner with the University of Louisville on this trailblazing, sustainable building and provide students with a healthy, state-of-the-art facility.

Belknap Academic Building

What does this data mean?
Baseline: AIA 2030 Annual Energy Use Goal
Actual: The Measured Energy Use of This Project