Canadian Consulting Engineer

Vancouver’s Aquarium

Water from the Pacific Ocean has long been used to fill tanks and pools at the Vancouver Aquarium, but now it is also being used to cool a new Learning Centre on the site.

August 1, 2007   By Jean Sorensen

Water from the Pacific Ocean has long been used to fill tanks and pools at the Vancouver Aquarium, but now it is also being used to cool a new Learning Centre on the site.

There exists a dilemma in attempting to teach future generations about the need to preserve waterways and ocean resources in order to sustain marine life. That learning process involves the use of facilities — buildings and exhibits — which draw upon precious natural resources such as water, heat, light, and energy.

For that reason, a new education building at the Vancouver Aquarium Marine Science Centre was designed to minimize its use of those precious natural resources. The new “Aquaquest” learning centre is intended to give visitors more than a watery definition of sustainability in building construction.

“We want people to understand not just the marine life but what is happening to their environment,” says Dr. Dennis Thoney, director of facilities operations and animal management for the entire Vancouver aquarium facilities.

In total, the aquarium houses 70,000 water creatures in what is considered to be one of the largest and finest collections in North America. It is also a base for scores of researchers who labour on and off site to study ocean life and habitats.

As well, the aquarium must accommodate the hundreds of thousands of visitors who move through its facilities each year. By 2008 the figure is expected to reach one million.

The facilities are spread over almost three acres near the entrance to Vancouver’s Stanley Park. (The aquarium recently got permission to expand over another 1.5 acres, but funding is not yet in place.)

Since it opened in 1956, the aquarium has taken advantage of its ocean location and draws water from Burrard Inlet for most of its pools and tanks. More recently, however, the aquarium has begun to use ocean water for cooling one of its buildings — the new Aquaquest, Marilyn Blusson Learning Centre.

Supporting life for a diversity of creatures

The life support systems for the exhibits are the most critical function at the aquarium.

There are approximately 15 large pools and tanks greater than 6,000 U.S. gallons among the aquarium’s 154 aquatic displays. The largest pool is the Wild Coast pool, which houses white-sided dolphins. It holds about 1 million U.S. gallons, measuring 7 metres deep and 48 metres across. The Arctic Canada exhibit, which housed Beluga whales, holds about 500,000 U.S. gallons. Most of the large pools are saltwater, although there is a 24,000-U.S. gallon freshwater tank for large Amazonian fishes.

Other large pools contain harbour seals and sea otters, as well as an off-exhibit research pool housing a Steller sea lion. (Steller sea lions are listed as a threatened species.) The largest tanks have underwater viewing areas, with acrylic transparent walls that can be up to 180-mm thick.

The ocean water intake is via two 250-mm PVC pipes, which can supply 1,200 U.S. gallons per minute and normally draw in water at the rate of 600 U.S. gallons per minute into the facility.

The incoming seawater, which averages between 7-13C, is subjected to primary treatment by passing it through a gravity sand filter.

From there the water is circulated into the various indoor tanks and outdoor pools where it undergoes secondary treatment and is brought to the correct temperature depending on the exhibit. The temperatures range from around 8C in the Arctic pools, to as high as 28C in the shark tanks.

Kent Hannestad, who began working at the aquarium three decades ago as a part-timer while he was in high school, is now responsible for overall management of the operating systems. The semi-open systems circulate 2 million U.S. gallons of ocean water (and some fresh water) through the various outdoor pools and tanks every 120 minutes, he explains.

“Redundancy is built into the systems,” Hannestad says. If one pump fails, the other pumps are still operational to give staff time to fix the problem. The response must be immediate in order to avoid the water quality deteriorating and affecting the animals and fishes.

Each of the large exhibits has a recirculating filtration system, with a water exchange that depends on the exhibit. Filtered seawater is available for backwashing filters and to dilute nutrients.

Dr. Thoney and Hannestad explain that the secondary treatments include a variety of old and new technologies. The aquarium was one of the first to use the vacuum diatomaceous earth filters, starting in the 1970s. These are being replaced with high rate pressure sand filters in containers. Also used are rapid open bed sand filters, screen drum filters, foam fractionators and ozone treatments. Biological filtration towers contain bacteria that break down ammonium in the animals’ excretions into nitrates. The towers also remove any residual ozone.

The ozone treatment is automated, but most of the equipment and systems are operated manually. For the planned expansion, Dr. Thoney says the aquarium plans to automate all of the systems.

The Aquaquest, Marilyn Blusson Learning Centre

At the northeast corner of the aquarium site sits the new 4,645-sq.m (50,000 sq. ft.) learning centre. The objective, tells Goran Ostojic, P.Eng., was to make the building systems as passive and sustainable as possible. Ostojic is a partner in Vancouver’s Cobalt Engineering, who were the mechanical engineers on the new learning centre. Stantec is the prime consultant and architect.

Besides wet laboratories, research areas and classrooms, the centre has a gallery and viewing windows to provide children and other visitors with insight into how marine animals live in harmony with their aquatic world. But the centre is also meant to challenge modern engineering and architectural concepts of how people live with their own land environment.

The learning centre opened in 2006 and is the first aquarium to seek LEED Gold certification in North America. The Leed (Leadership in Energy and Environmental Design) application is currently being evaluated by the U.S. Green Building Council.

The new centre required an older administration building on site to be removed and the structure’s materials — concrete, steel, glass and frames — to be either reused or recycled. The footprint of the building has been minimized, using a four-storey stacked design with two floors below grade. The new structure uses recycled steel rebar and sustainable fly-ash concrete.

One outside wall of the centre is a statement of how integrated the facility has become to its natural surroundings. It has lush green vegetation trailing down the concrete face. Run-off water from the roof is used to irrigate the green wall. Inside, the building’s interior opens up to wide open spaces, drawing natural daylight from large windows, even in stairways. The natural light is augmented by lightwells and reflective pools.

Radiant cooling using ocean water

A portion of the ocean water intake is directed towards the learning centre via a new titanium heat exchange system. The cool ocean water is then funneled into pipe buried in the floors and ceilings. “We are using the ocean’s energy and it is available all year,” Ostojic says.

When heat is required, the radiant system draws from the new building’s heat exchange system and also from the aquarium’s new natural-gas high-efficiency condensing boilers, located in a central plant.

For ventilation, Cobalt has designed an air displacement system that introduces outside air through vents at the building’s lower level. As this cold air is warmed by equipment and by visitors as they pass through the building, it rises to the higher levels and ultimately exits through a heat-recovery system at the building’s roof. “We take the energy back from the air,” Ostojic says. He points out that the displacement system provides superior indoor air quality. Carbon dioxide sensors gauge how many people are in the building and
automatically adjust the fans and other equipment to ensure the right amount of air is provided. All the building HVAC systems are automatically controlled in the learning centre. And operable windows have been matched to allow cross-ventilation within the spaces on warm days.

While rainwater is used for irrigation, it is also captured from the roof in a storage tank and used for low-flow toilets and urinals. The roof drains lead to an existing 15,850-U.S. gallon reservoir located in the basement.

The building’s outside walls and floors are concrete ranging in thickness from 200 to 300 mm. Equilibrium Consulting were the structural engineers.

The European software program TAS Building Designer produced by EDSL was used to do a thermal analysis. The program includes a systems and controls simulator to model a building’s environmental, energy and comfort performance. While the building is still in its first year of performance, estimates are that its energy performance will be 42% more efficient than a National Energy Code of Canada for Buildings rating, tells Ostojic.

Three key elements combined to give the structure potential to achieve LEED Gold status, says Ostojic. They are the software to be able to model a highly efficient building, an integrated design team approach (engineers, architects, constructors as well as the aquarium management), and finally, the aquarium management’s vision and willingness to consider new ideas.

“Technology is just a tool, but you need people with vision to be able to transfer it properly to the final product,” Ostojic says.

Project: Aquaquest, Marilyn Blusson Learning Centre

Owner: Vancouver Aquarium Marine Science Centre

Prime consultant: Stantec Architecture

Mechanical: Cobalt Engineering (Goran Ostojic, P.Eng., Jason Manikel, P.Eng)

Electrical: R.A. Duff & Assoc.

Structural: Equilibrium Consulting

Commissioning: KD Engineering

Construction: Stuart Olson Construction


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