Northeastern University’s President Joseph Aoun set out to develop a new campus district for the esteemed Boston, MA university. First up in this new district is the Interdisciplinary Science & Engineering Complex (ISEC), a high-performance sustainable laboratory on track to achieve LEED Gold. The complex will be open to outside researchers in the interrelated fields of computer science, basic sciences, health sciences, and engineering.
Arup was selected by the architecture firm Payette to provide mechanical, electrical, and plumbing engineering, as well as energy modelling, façade consulting, sustainability, and lighting design services for the project. Using advanced computer modelling to integrate the design of the building systems and façade, the design team significantly reduced operational costs and improved energy efficiency.
Early on in the design process we utilised Revit as we developed the mechanical, electrical, and plumbing systems. Reviewing these models with the architect and the university’s facilities staff helped the entire project team understand the system strategies and allocate space for future maintenance. Ultimately the model was used as an integral part of the calculation and specification process. This early integration allowed for collaborative and cohesive project development and was key in realising the high performance of the facility.
The project, which abuts the Ruggles Massachusetts Bay Transportation Authority station, also initiates the University’s expansion of academic facilities across the rail lines to Columbus Avenue. The project benefits the surrounding community as well; a pedestrian bridge (currently in design by Arup’s structural engineers in collaboration with Payette) will span the commuter-rail tracks to allow residents, workers, and students to easily and safely navigate their way through the site.
Ambitious energy goals, innovative solutions
The Massachusetts Stretch Energy Code calls for new buildings to perform 20% better than required by base code. The ISEC surpasses this requirement, achieving 33% energy-cost savings over code and 75% energy savings compared to typical laboratory performance. To accomplish this, Arup engineered several major energy conservation measures:
Cascade air system
The cascade air system is the biggest contributor to energy savings at the ISEC. In a typical scenario, laboratories have a dedicated HVAC system, an expensive feature to construct and operate. At the ISEC, the cascade system recovers conditioned air from the offices and atrium of the building, then transfers it to the lab, saving energy and reducing costs.
Arup designed a hydronic run-around coil system, recovering energy from the lab exhaust air to pre-condition the outdoor air, targeting the heating as needed to either the offices or labs, and optimising the efficiency of the system. The coils are designed to minimise the size of the fan motor and extract as much energy as practical before the exhaust is discharged.
An optimised building façade
We used performance and life-cycle analysis to optimise the façade design, ensuring both occupant comfort and energy efficiency. The northern part of the ISEC complex, which houses the energy intensive labs, is the focus of thermal improvements; at the southern exposure (where low-energy functions such as offices are located), triple-glazed windows and a shading system work to maximise daylight while minimising energy consumption.
Chilled beam technology
Using active chilled beam technology significantly reduces the energy consumption compared to conventional air conditioning. In this system, supply air to the space is directed through nozzles on either side of a heat exchanger coil, creating a pressure difference. This pressure difference pulls air from the space over the coil, cooling or heating it, and then mixes with the supply air to be delivered to the space. Arup’s comfort-modelling software balanced the downdraft and the ambient temperature to ensure a pleasant environment.
To optimise the efficiency of the chiller and heating system, Arup installed a heat-recovery chiller, which simultaneously generates hot water and chilled water. This reduces the run-time of the boilers for laboratory re-heat in the summer and shoulder seasons, and for the pre-heat of the domestic and laboratory hot water systems.