Your toolkit for good lab
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Figure 1: Wind interacting with building massing and rooftop exhaust stacks.
given that hazardous constituents won’t be
released simultaneously from all hoods.
With respect to the type of fan, centrifugal
fans are often used as they can supply high
exhaust airflows and high pressures. Axial fans
can be pursued, although they often consume
more energy because the fan spins faster for the
No less important from an exhaust dispersion perspective is the proper design of the
stack tied to the exhaust fan. Figure 1 illustrates
this importance, showing the complicated rooftop turbulence that can impact proper plume
dispersion. This turbulence is created by the
approaching wind interacting with the massing of the building itself and any surrounding
Several options can be considered to limit
the influence of this turbulence. First, exhaust
stacks should be vertical and uncapped and dis-
charged at a reasonably high exit velocity, ide-
ally greater than 3,000 fpm. This will afford the
plume good discharge momentum to overcome
the turbulence. Second, stacks should be situat-
ed away from nearby obstructions such as stair
towers, mechanical rooms or adjacent higher
roof levels. Ideally, the stack should be situat-
ed on the highest roof possible to minimize
impacts on dispersion. Third, exhaust stacks
should discharge at a minimum height of 10 ft
above the roof for good dispersion and the pro-
tection of the breathing space of any personnel
working in the immediate vicinity.
Wind tunnel dispersion modeling is one
means of navigating these many factors to
determine the optimal exhaust fan and stack
design for any lab building. This type of mod-
eling is well suited to account for the significant
impacts surrounding buildings and local ter-
rain can have on plume dispersion. Wind tun-
nel modeling can also be used to quantify fan
energy savings by demonstrating what level of
fan turndown can be pursued, while still meet-
ing applicable health and odor thresholds.
Mark Hallman, LEED AP, is a Senior Project
Engineer with Rowan Williams Davies & Irwin
Inc. (RWDI). Hallman has provided consulting
services on exhaust and intake designs for a
variety of new and existing lab facilities in the
educational, medical and research sectors.
;AECOM COMPLETES ACQUISITION OF URS CORP.
AECOM announced the company has completed its acquisition
of URS Corp. The acquisition further diversifies and broadens
AECOM’s market presence, as URS brings strong sector expertise in important markets, including oil and gas, power and
government services. URS also adds to AECOM’s construction
capabilities, deepening a core competency that AECOM will be
able to leverage across its global platform.
;SANDY SHAPOSKY JOINS HDR’S S&T PRACTICE
Sandy Shaposky has joined HDR Architecture’s S&T practice as
Director of Business Development in Bethesda, Md. She will
work closely with East Region S&T Director Kevin Jelinek to
create connections and grow business with academic and corporate clients in the Mid-Atlantic region, as well as cultivate key
partnerships within the robust regional healthcare and federal
marketplaces. Shaposky has six years of experience in architecture marketing and business development.
; SMITHGROUPJJR ADDS SCOTT KREITLEIN AS S&T STUDIO LEADER
SmithGroupJJR has hired Scott Kreitlein, AIA, LEED AP, as leader of
the S&T Studio at its Phoenix office. He joins SmithGroupJJR from
HDR Houston, where he was S&T principal. Kreitlein, a 20-year
architecture veteran, is recognized for his expertise in the design
and planning of biocontainment and animal holding facilities, a
specialty that will strengthen SmithGroupJJR’s S&T practice.
;GZA GEOENIRONMENTAL INC. PROMOTES TERESE
KWIATKOWSKI TO SENIOR PRINCIPAL
GZA GeoEnvironmental Inc. has announced that Terese Kwiatkowski has been promoted to Senior Principal. Kwiatkowski,
with GZA for 29 years, holds a B.S. in civil engineering from
Worcester Polytechnic Institute and an M.S. in civil engineering
from Virginia Tech. She is a geotechnical engineer specializing
in large transportation infrastructure projects and building
development projects for colleges/universities, medical institutions and commercial, retail and residential developments.