The Seattle Aquarium, located at Pier 59 along the Seattle waterfront, underwent a $60,000,000 renovation; its first major renovation in 30 years. WSP USA provided MEP engineering, including an underfloor air distribution system and natural ventilation.



  • Seattle, Washington, USA



Project Status

  • Completed in 2007

Updating the Aquarium

Utilizing titanium shell and tube heat exchangers, the air conditioning system designed by WSP rejects its heat into the perpetually circulating aquarium filtration water. This integration and cooling strategy will save valuable energy helping further evolve sustainable design solutions.

An underfloor air distribution system was designed for the main exhibit space, supplying conditioned air to the raised underfloor plenum. The air migrates through the plenum and is then fed into the interior zone of the exhibit space through floor “swirl” type diffusers. Tiles in the raised floor house the swirl diffusers and can be easily moved. This allows the aquarium staff flexibility and expanded comfort control as future displays and attractions are rotated through the main exhibit space.

The mechanical system employs a “mixed mode” strategy with operable windows for natural ventilation. The mechanical system is capable of turning off completely when outside air conditions are mild and the interior zone maintains comfort levels. Enhancing this natural ventilation is the aquariums prime location over the temperate waters of Puget Sound; cool pacific breezes off the sound help create the ultimate in “free cooling” for further increases in sustainability.

The project also included the removal and reinstallation of the existing services to the pier: water, sewer, gas and fire services; as well as the relocation of mechanical and electrical equipment rooms to more central locations.