Boston College - Smoke Test
01.25.12 / Jan Taylor, AIA, LEED AP
ARC is currently completing renovations of the former Archdiocese of Boston’s Chancery Building to accommodate the college’s University Advancement department on its Brighton Campus. One of the goals of the project is to consolidate University Advancement (UA) - which is currently located in three different buildings on three different campuses - in one location to foster interaction among the departments. Working together, ARC developed an understanding of the department’s needs and desires. In addition to an open and interactive environment, the new facility is designed to bring natural light into each floor plate to enhance the working environment for all employees. A new addition creates a sunlit three story atrium around which the departments are organized and provides light, circulation and an important gathering space for the building occupants.
During the design process we looked at a number of options for the new space created, we considered creating an outdoor courtyard, but needed an interior gathering space to meet program requirements. We considered several options which close the second and/or third floors off from the space, eliminating the “atrium” in the code sense of the word. Ultimately we decided that UAs vision required a space that was truly open and interactive.
The inclusion of a true atrium in the project necessitated the development of a smoke evacuation system for the purposes of life safety. This system essentially sucks the smoke out of the building in the event of a fire. And is comprised of two primary parts, a pair of fans on the roof, to pull the smoke out, and sufficient openings to outside (free area) which supply air to make up for the air being evacuated (make-up air).
Initial estimates at code prescribed volumes and velocities indicated that we would need 110,000cfm of make-up air and that this would require 550sf of free area in the atrium to introduce this air at the code prescribed velocity. Computational Fluid Dynamic (CFD) modeling allowed us to demonstrate that the make-up air could be introduced at a higher velocity, allowing us to reduce the required amount of free area, further tweaking of the model also showed that the system was fully functional at 95,000cfm. Our final design provided 185sf of free area for the air, introduced at higher velocities. This 185sf was achieved using both entrances – four pairs of doors – on auto-operators connected to the system, and two large supply ducts, bringing air through the mechanical room from the outside and delivering it at the first floor level through two large wood louvers. The area of open space in these louvers was carefully calculated to insure that our total free area was met.
On January 4th, the system was tested by the Boston Fire Department using a large smoke bomb, to set off the system. To everyone’s great relief the system performed exactly as designed and the building is ready to move in to.
Watch the video