Ventilation and exhaust analysis for an advanced research laboratory with a cleanroom
Harvard’s Laboratory for Integrated Science and Engineering (LISE) is a 135,000-square-foot facility that contains specialized research environments focused on nanoscale and mesoscale science. Situated amid a cluster of existing science buildings, LISE was designed to boost collaboration among scientists studying materials at the atomic scale while also connecting them with researchers in nearby laboratories.
The building’s two key objectives--to facilitate leading-edge research and to play a connective role in the scientific communities at work in the cluster of buildings in Harvard’s North Yard science complex--each gave rise to technical challenges. We were engaged to provide modeling and analysis to help the lab’s designers meet those challenges.
One of the LISE building’s most important research assets is its cleanroom, a large, dust-free laboratory with precisely controlled environmental conditions designed to enable nanoscientists to study particles and create devices at atomic scales (several times smaller than dust particles). To support scientists’ work effectively, the cleanroom required a sophisticated ventilation system that would exclude nearly all dust and ensure consistent, unidirectional air flow.
Situated in an area of the Harvard campus bustling with scientific endeavour, the LISE site was an excellent location for a collaborative hub for researchers, but its proximity to other labs also presented design challenges. LISE and its neighbours all have unique and stringent ventilation and exhaust requirements; because LISE is taller than its neighbours, the design of its rooftop air intake system had to be informed by an awareness of nearby facilities’ exhausts. The exhaust discharge associated with chemicals used in LISE’s own cleanroom also had to be managed with adjacent facilities and overall campus and neighbourhood air quality in mind.
Finally, LISE was built on a site that had included a well-traveled footpath. Pritzker Prize-winning Spanish architect Rafael Moneo designed the building in such a way as to preserve that route, placing the main part of the building on three pedestals and allowing pedestrians to pass through a portico at grade. In addition to our work to support laboratory performance, we were also engaged to perform a pedestrian-comfort analysis focused on the experiences of people simply walking past this advanced research facility.
After working with the designers to gain a holistic understanding of the building, its lab facilities, and its environment, we started our analysis on the three site-specific air challenges.
Cleanroom ventilation. Using the designers’ planned ventilation approach, we conducted computational fluid dynamics (CFD) modeling to gain a detailed understanding of how the proposed design would perform. We studied airflow patterns throughout the 10,000-square-foot cleanroom, devoting special attention to the ways in which equipment geometry and internal heat sources might create adverse flow conditions. By performing simulations of several possible ventilation and equipment configuration scenarios, we were able to deliver insights that helped the designers optimize the laboratory environment for sensitive nanoscale and mesoscale research, supporting enhanced performance by preventing potentially problematic airflow patterns.
Exhaust dispersion. Our team carried out wind tunnel tests and modeling work to ensure LISE’s safe and comfortable coexistence with campus neighbours, including nearby laboratory facilities; we collaborated in this work over several years with the design team and with Harvard’s Environmental Health and Safety group. As part of this exercise, we worked with the designers on the location of the new air intakes for the LISE Building, taking into account potential impacts from the existing exhaust sources on the nearby laboratory buildings. Using detailed exhaust dispersion and wind tunnel modeling, and testing multiple release scenarios in diverse weather conditions, we were able to develop informed and conservative assessments of the risk of chemical releases from the cleanroom and other laboratories. We worked closely with Harvard and the design team to communicate our findings and their implications to interested stakeholders. Ultimately the university and its community were confident that the exhaust design was effective in safely diluting any substances scientists expected to use in the cleanroom.
Pedestrian comfort in the portico. We conducted a wind tunnel study of pedestrian wind conditions under two site configurations: we evaluated the existing conditions prior to the construction of the new LISE building, and assessed the change in conditions within the portico passageway after the building was in place. A comparison of conditions pre- and post-construction, which included areas both under and around the new building, concluded that the building would not have a significant effect on pedestrian comfort. Taken together, the analyses we delivered helped the LISE design team optimize their plans and move forward with increased confidence about how their designs would perform. The intelligence our experts provided also helped Harvard communicate effectively with its stakeholders about the nature of the risks the new facility presented and the precise measures being undertaken to ensure the safety of building occupants and community members. The result was a high-performance laboratory that enjoyed a high degree of community support.
Construction of LISE was completed in 2007 and it has been operating safely and successfully for almost a decade, supporting top researchers on one of the most active frontiers of science. Administrators note that LISE has brought Harvard’s facilities up to the level of other top cleanroom-equipped nanoscience and mesoscience institutions such as MIT and Stanford. Quoted in the Harvard Gazette, physics professor Charles M. Marcus summed up the building’s success as both a technical feat and a presence on campus: “it solve[s] a huge number of technical and logistical problems associated with putting a technically sophisticated building into a dense space, without losing any of its elegance and uniqueness.”