Seattle Aquarium exhibits major change

The historic landmark Seattle Aquarium, located along the Seattle waterfront, welcomes around 700,000 guests each year to its famed marine exhibits. Housed in a 100-year-old building, the Seattle Aquarium was in need of a major renovation to meet the needs of its guests and marine wildlife.

The historic landmark status of the aquarium posed many challenges to Flack + Kurtz, a mechanical and electrical engineering firm headquartered in New York with local offices in Seattle.

“One of the initial challenges was to see if we could ventilate the building naturally,” said Allan Montpellier, PE, senior vice president of Flack + Kurtz. “We studied that extensively. The difficulty we ran into was that there is a lot of south-facing exposed lighting that we couldn't protect very well because of the historic building status, and the character of the building would be compromised if we added shading.”

Located on Piers 59 and 60 in Elliot Bay, the building and pilings needed a renovation to accommodate new exhibit space. In 2003, officials discovered that the accelerated decay of the all-timer piling system threatened the aquarium. The decay is largely due to Bankia, or marine worms, that eat wooden structures; it had destroyed much of the pilings. It was not practical to repair the rotted timber deck, and officials at aquarium officials decided to renovate exhibit space and take advantage of required construction.

Flack + Kurtz, Seattle, needed a successful logistics plan for the renovation. Phasing had to be coordinated with the pier renovation and ongoing aquarium events, as the aquarium remained open during renovation. Studies showed that it would be less expensive to complete the renovation if the facility remained open. The challenge: Flack + Kurtz had to renovate the building while it was occupied.

The project began Aug. 9, 2004, and opened to the public on June 22, 2007. The $60 million renovation included a removal and reinstallation of existing services to its pier: water, sewer, gas, and fire services. The renovation also included moving the electrical and mechanical equipment rooms to a more central location. This marked the aquarium's first major renovation in 30 years.

“We felt privileged to have participated in such an outstanding renovation project that gives so much back to not only the local community, but also to the many visitors who come to the Seattle area,” Montpellier said.

With 18,000 sq. ft of exhibit space, the Seattle Aquarium highlights a jaw-dropping 120,000 gal “Window on Washington Waters” fish tank, which has a 13-ft thick x 17 ft tall x 39 ft wide viewing window. The tank is filled with fish and invertebrates, representing a slice of life from Seattle's Puget Sound.

The new foundation replaced 12,000 sq. ft of exterior timber aprons with a concrete lateral frame structure. To maintain the historical landmark's integrity, the design's façade was removed by a crane and transported for restoration to another off-site location. After nine months, it was reinstalled as a non-structural façade in its original location.

Flack + Kurtz recognized early in the design process that a synergy between the 20,000 sq. ft aquarium's filtration system and the exhibit space's HVAC system could be a valuable reclamation of resources. Engineers installed titanium shell and tube heat exchangers into the air conditioning system. This allows the system to reject its heat into the circulating aquarium filtration water.

“This behind-the-scenes integration and cooling strategy will save valuable energy,” Montpellier said.

Entering the aquarium, The Ackerley Foundation Puget Sound Great Hall is a light-filled space that is distinguished by its grand staircase. All of the wood in the wooden beams and trusses of the grand staircase was salvaged from the demolished portion of Pier 59.

After speaking with exhibit designers and due to the aquarium exhibit size, Flack + Kurtz knew there had to be a more efficient way of pumping water into the exhibits.

“The exhibit designer planned to pump a lot of water from the sound and do some filtering from their end,” Montpellier said. “But once the water goes into the tank, there is an overflow from the tank that goes back into the sound. We looked at that outfall and asked if we could use that water for our heat rejection. From our standpoint the heat rejection that we are contributing to it is less than half a degree. So it's basically a very efficient way of cooling the space.”

For the main exhibit space, engineers chose an underfloor air distribution (UFAD) system for heating, cooling, and ventilation. In this system, the central air handling unit supplies conditioned air to the raised underfloor plenum. The air migrates through the plenum and then is fed into the interior zone of the exhibit space through floor swirl-type diffusers.

Exterior zones are served through an underfloor fan-powered terminal with hydronic heating coils and floor-mounted linear diffusers. Tiles in the raised floor house the swirl-type diffusers and these tiles can easily be moved. This is an important feature for the aquarium staff, as it allows them flexibility expanded comfort control when displays and attractions are rotated through the main exhibit space.

The UFAD system also supplies electrical power and data distribution through its raised access floor system in the main exhibit space. This allows for additional flexibility as the exhibit space changes.

Engineers installed a mixed mode feature into the aquarium's mechanical system. For natural ventilation, the mechanical system turns off completely when outside air conditions are mild and the interior zone maintains comfort levels. In this mode of operation, motorized louvers, which are located in the upper floor of the aquarium, open and aquarium staff may open lower level windows for ventilation. This is a feasible option, as the aquarium's prime location over Puget Sound allows temperate breezes to cool the facility.

During renovation, the Flack + Kurtz decided not to construct the electrical transformer vault until the Pier apron was complete. In order for the Seattle Aquarium to remain open during renovation, main electrical service temporarily was fed from Seattle City Light to a new main switchboard. In addition to construction power, the temporary feed allowed support to the electrical demand loads of pier tenants.

With great fanfare, the renovated Seattle Aquarium opened to the public. A record-breaking 14,461 guests visited the improved building that weekend, which marks the largest attendance numbers ever recorded in a three-day period.