Laboratory workstation odour control at MaRS/Toronto
By Paul A.Tetley
Rooftop installation of the mixed flow impeller systems.
Buildings that generate odours
are under increasing scrutiny
not only by neighbours, but
regulatory authorities as
well. This, despite the fact that for the
most part, odours are perceived differently
by different people. No matter; if
a facility’s odiferous exhaust is a
source of complaint, it should prompt
a quick response by the “offender” to
avoid further problems and remain a
“good neighbour.”
While many people think of odiferous
exhaust as emanating from chemical
processing or manufacturing
plants, or other industrial facilities,
many scientific and research laboratories
must also manage odiferous
exhaust emissions. This requirement
results from not only a good neighbour
policy but sometimes serious health
issues for the building’s workers. In
almost all cases these laboratories use
workstations equipped with sophisticated,
computer controlled fume hood
exhaust systems. The chemicals used
at these workstations may be toxic,
noxious, odiferous, or some combination.
While there are many ways to
exhaust laboratory workstations into
the atmosphere, over the past few
decades one method known as “mixed
flow impeller technology” has become
increasingly popular for these applications.
Safely exhausting laboratories
at the MaRS Centre
This technology is playing a major
role at a new research facility known as
the “MaRS” (Medical and Related
Sciences) Centre in Toronto, Ontario,
(www.marsdd.com). MaRS was established
about five years ago for the purpose
of “promoting the growth of small
research related technology companies
and successful commercialization of academic
research.” MaRS is the first facility
of its kind in Canada, and is modeled
after similar facilities in the US.
Essentially, the model for these kinds of
research centers is to seamlessly integrate
state of the art research and development
facilities, commercial
business entities,
and related support
services within an
overall interactive
campus development.
The MaRS complex
encompasses
1.5 million square
feet and is valued at
about $345 million.
“With its proximity
to some of the leading
minds and institutions
in Toronto’s
bioscience cluster,
MaRS is ideal for
our drug research
and development
work in Canada,”
says Dr. Hunter Jackson of NPS
Pharmaceuticals in Salt Lake City,
Utah. The complex has been constructed
in two different phases: Phase One is
comprised of 700,000 square feet in
two towers, and Phase Two will comprise
600,000 square feet with occupancy
scheduled for next year or 2007.
Fume hood exhaust is
critical at MaRS
The scores of research laboratories
at the MaRS facility – while designed
for many functions – share a common
characteristic. Their laboratory workstation
fume hoods also require safe
and efficient exhaust systems to prevent
any possibility of exhaust reentrainment
into the facility or adjacent
buildings; to eliminate neighborhood
odours; and, to comply with applicable
pollution abatement standards, among
other considerations.
Proper management of these
exhaust emissions – particularly at the
building’s biosafety level (BSL) laboratories
– is critical, since mismanagement
will likely cause serious implications.
Consequently, the consulting
engineers responsible for these functions
at MaRS (Smith & Andersen,
Toronto) specified mixed flow
impeller roof exhaust systems for its
laboratories. In doing so, Smith &
Andersen worked closely with Belnor
Engineering (Toronto) which has represented
the manufacturer of these systems
for many years.
The mixed flow impeller fans for the
laboratories’ workstation fume hoods
eliminate re-entrainment possibilities
into the workplace, prevent neighborhood
odours, and aid compliance with
appropriate pollution abatement standards.
As an added feature the roofmounted
fans also help meet applicable
aesthetic codes with regard to eliminating
tall exhaust stacks above the
roofline. This last point is important,
since many times community ordinances
restrict total building height, or
height above the roofline of various
appurtenances and accessories. In addition,
tall exhaust stacks usually impart
negative connotations in a community –
in other words, another neighborhood
polluter!
According to Danny Vistolli at
Belnor, the City of Toronto imposed
building height restrictions on the
MaRS complex, mainly because existing
buildings in the vicinity are in the
heart of the city’s downtown. “This
was another consideration for use of
low profile mixed flow impeller exhaust systems,” Vistolli said.
MaRS’Toronto Medical
Discovery Tower
The mixed flow impeller systems at
the MaRS complex are mounted on its
Toronto Medical Discovery Tower
(TMDT). Twelve low profile fans are
connected with four plenums (each
plenum accommodates three individual
fans) for a total air moving capacity
of 280,000 CFM. Belnor also
worked closely with the facility’s owners,
the contractor (Ellis Don
Construction), as well as Smith and
Andersen.
Mixed flow impeller technology
offers many advantages
Laboratory workstation fume hood
exhaust systems incorporating mixed
flow impeller technology offer many
advantages for research facilities,
pharmaceutical pilot plant processing
areas, and other enclosed, controlled
environment areas such as clean rooms
and vivariums.
When asked about mixed flow
impeller systems, a Belnor spokesperson
said that his firm had used them
for other projects with considerable
success, and that one of the main reasons
for their use was the elimination
of re-entrainment possibilities to
assure worker safety, along with elimination
of tall, unsightly exhaust stacks
on the building’s roof. “Tall exhaust
stacks would have required major (and
costly) roof reinforcements, guy wires,
pitch pockets, and other expensive
hardware and equipment which was
not necessary with the mixed flow
technology approach,” he commented,
adding that his firm has also received
an additional order for four more similar
systems for the MaRS complex.
Paul A. Tetley is with Strobic
Air Corporation.
Information at www.strobicair.com
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