Canadian Consulting Engineer

By Nerys Parry   

Safeguarding Nature

Engineering

The cold hits you like a wall, makes you step back. The chilled halogen light is slow to brighten, but when it does, you see that the -40 freezers at the National Wildlife Research Centre at Carleton...

The cold hits you like a wall, makes you step back. The chilled halogen light is slow to brighten, but when it does, you see that the -40 freezers at the National Wildlife Research Centre at Carleton University in Ottawa look much like any other storage room. Dark walls, wire shelves, stack upon stack of cardboard boxes. Nothing spectacular, except the goose-pimpling cold — and the fact that inside those ordinary looking boxes is something both unique and precious: portions of the country’s largest collection of frozen wildlife tissue specimens, crucial biological evidence used by Environment Canada scientists and university researchers to study the impact of environmental contaminants on wildlife, and to investigate past and future environmental trends.

The new five-storey, $15-million centre located on the southeast corner of the Carleton University campus in Ottawa houses samples of more than 88,000 specimens. Many of these samples have been dissected, homogenized or manipulated over the years, and the collection, which began in 1963, is now estimated to contain over 500,000 subsamples. Depending on the intended use of the samples, they must be stored in either the -40 walk-in freezers, or -80 chest freezers, or the ultra-low -150 liquid nitrogen tanks. Because the collection is so valuable, freezer temperatures and other storage parameters are monitored 24/7. The freezers also have back-up power and an emergency liquid nitrogen supply to ensure that even in the event of a power outage Canada’s biological history will be protected.

But the Wildlife Centre is more than just a specimen bank; it also houses a 100-sq.m. greenhouse and plant growth chambers, more than 20 different laboratories of all types and sizes, and plenty of office space for both Environment Canada scientists and university graduate students.

The centre was constructed in 2002 in a joint venture between Carleton University and Environment Canada, and has benefited both partners. Working through Carleton, Environment Canada was able to increase their teaching connection, and obtain newer, better lab space in a relatively short period of time. As for the university, it gained “synergist research opportunities” — not to mention access to 5,165 square metres of new laboratory and office space, and an estimated $4 million in new equipment.

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Servicing the walk-in freezers

Because of the variety of equipment and laboratory uses, the design of the mechanical and electrical systems proved to be an interesting challenge.

“The building is certainly not a typical simple lab,” says Andr Bogdanowicz, P.Eng. of Goodkey Weedmark & Associates Limited (GWAL), consulting mechanical and electrical engineers on the project. “The complexity of the systems made the technical design quite intense, challenging and enjoyable.”

Take the liquid and gas systems, for example. Along with the usual steam and compressed air, a liquid nitrogen system needed to be developed to feed nitrogen from a central storage tank outside into individual tanks within the laboratory; this required the use of special vacuum piping and extra safety precautions, such as the installation of oxygen monitors. There is also a central de-ionized water system in the penthouse that uses various in-situ methods (chemical processes, carbon filtration, ultraviolet light, reverse osmosis) to treat the city water, which is then distributed to the various labs throughout the building.

Team strove to reduce the building’s environmental footprint

To add to this complexity, the design team strove to reduce the environmental footprint of the building where possible, using sustainable design principles. There are green roofs, a rainwater collection system that drains into a small wetland area, operable windows in the office areas, which allow both for natural air flow and individual heat control. There is also a main circulation stair to encourage stair use — all of which have an impact on the mechanical systems.

The architects used a “compact floor plate,” a regular repeating square floor plan that minimizes the ratio of exterior wall vs. interior floor area and so reduces overall heating and cooling loads. Still, some areas required supplementary cooling, such as the laboratories, where the density of electrical research equipment generates excess heat. In these places, dedicated standalone supplementary cooling units were connected to a common heat recovery loop containing propylene glycol, and also connected to an air-cooled heat exchange unit.

Because the standalone units often increased the amount of recirculated air within the laboratories, the overall air distribution design had to preserve appropriate air flow patterns and maintain containment conditions at the fume hood inlets.

Laboratory ventilation and exhaust systems

To further reduce energy, the team chose to use variable air volume (VAV) supply and exhaust systems, which vary the air flow in response to data provided by sophisticated tracking equipment in each laboratory. Many of the fumehoods are also equipped with motion sensors that detect when someone is near and the airflow is adjusted accordingly. To further reduce energy consumption, the ventilation system is equipped with a glycol heat recovery run-around system, which transfers the heat from the laboratory exhaust system and uses it to preheat or pre-cool the make-up air supply. Together, the VAV lab system and heat reclamation system save in the range of $55,000 per year in energy costs when compared to a traditional system.

Modular service shafts

Not only did the design have to be green, it also had to be flexible. Because of the constantly changing world of research, each laboratory’s requirements may alter over time. One now considered level 1 (i.e. without fumehoods) might in the future need to be modified to a level 2 laboratory with multiple fumehoods, biological safety cabinets, stringent cleanliness requirements and gas/liquid infrastructure.

“The challenge,” says Bogdanowicz, “was to design a mechanical system where these complex requirements can be provided at every lab at minimal additional cost.”

The solution? Four modular service shafts, 700 mm x 2,000 mm, located adjacent to the main laboratories each contain mechanical infrastructure — supply air, general exhaust, fume hood exhaust and lab gases/liquid connections. The modular shafts can easily accommodate future upgrades or modifications. Primary mechanical equipment components were also sized and selected based on the average future potential load.

All these mechanical, electrical and distribution systems, present and future, meant a lot of services, and integrating these into the exposed concrete structure posed a particular challenge for the joint venture architects DSAI/KWC. Since, in an effort to reduce the materials, there are no ceilings in many areas, the location of services had to be coordinated carefully during both the design and construction phases, in a way that would not interfere with overall design.

“Our architect on site spent a lot of time on site with the contractor working out how they would do it,” says Doug Clancey, a partner at KWC Architects. Interference drawings, for example, were provided by the contractor so that discussions on the service locations could be held with all the trades involved before any installation took place.

The building automation and specialized laboratory system controls are coordinated

All these variable systems also mean a lot of controls, and so another technical challenge was the coordination of control systems. The building automation system had to interface with specialized laboratory environmental and airflow control systems without overlaps or gaps, and this took some coordination and involved two control suppliers.

“The use of two separate control suppliers on one job carries a risk of compromised systems due to the incompatibility of
software protocols,” explains Bogdanowicz. To mitigate these risks, GWAL held several coordination meetings with both control suppliers to review all the control algorithms and ensure that the overall control strategy and monitoring abilities were not compromised.

Sticking to the fixed budget

And of course, like all projects, one of the greatest challenges was to stick to the fixed budget.

“The program and the design were subjected to frequent scrutiny with respect to the cost,” says Bogdanowicz. “And design adjustments were made as required to stay within the budget.”

The design team rose to the challenge. “It was very successful,” says Clancey. “[The project] was delivered on time on budget. I think that Carleton managed it well and that they allowed the users, NWRC, to drive the design. Everybody worked well together throughout the process.”

After the success of the National Wildlife Centre, Environment Canada and the university forged ahead in another joint venture to construct an addition to the building next door, the Nesbitt Biology Building. The addition is a new geomatics facility used for habitat modeling and mapping, and the development of species conservation maps.

Carleton has also embarked on joint ventures with other universities, institutions and government agencies to construct new buildings. It is currently working with the Sudbury Neutrino Observatory to construct a facility two kilometres underground in INCO’s Creighton Mine where researchers are delving into the origin of the universe and the nature of matter. For consulting engineers working in the field of science buildings there are evidently some exciting opportunities — and challenges.

Nerys Parry is a freelance writer based in Ottawa.

Owner: Carleton University

Users: Environment Canada; National Wildlife Research Centre

Mechanical & electrical: Goodkey Weedmark & Associates (Andre Bogdanowicz, P.Eng., Michael Fontyn, P.Eng., Branislav Gojkovic, P.Eng., Jeff Coughlin)

Architects: Diamond and Schmitt (DSAI)/ Katz Webster Clancey (KWC), in joint venture

Structural: Adjeleian Allen Rubeli

Civil: R.V. Anderson Associates

Contractor: PCL

Project management: ZW Group

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