©2013 This excerpt taken from the article of the same name which appeared in ASHRAE Journal, vol. 55, no. 11, November 2013.
By Sean Abbott P.E., Associate Member ASHRAE
About the Authors
Sean Abbott P.E., is project manager at CDi Engineers, Lynnwood, Wash. He is a member of the ASHRAE Puget Sound Chapter.
Fire Station 2 is the oldest operating fire station within the City of Seattle. Built in 1921, it is a registered landmark structure and was among the first generation of fire stations built in the city to accommodate motorized fire-fighting equipment. It is still the busiest station in the city, handling approximately 12,000 calls per year from its location in Seattle's Bell Town neighborhood. The two-story building was originally constructed in an industrial style using cast-in-place concrete walls and beams. The six apparatus bays, support spaces, fire department offices and the beanery (kitchen and dining facility) are located on the ground level; residential quarters and an occupational health center are located on the upper level.
From the outset of design, the City of Seattle challenged the design team with renovating the building in a manner that would uphold the City of Seattle, Office of Sustainability and Environment’s policies and initiatives. Any new mechanical systems had to reduce energy consumption and the use of fossil fuels, while increasing indoor air quality.
They also requested a bunker gear drying room that could dry their wet gear more quickly than their traditional drip-dry method. To improve the station’s disaster survivability, the owner requested seismic and electrical upgrades, and required that all HVAC equipment would be added to the emergency power system.
Other major project goals included recreating Fire Station 2 as a gender-neutral facility, increasing the facility’s operational capability, and replacing the existing emergency dispatch center with a new occupational health center (OHC) that would serve the entire Seattle Fire Department.
Pre-Design Site Investigation
Following a preliminary survey of the station, the deficiencies in the existing mechanical systems became apparent. The building’s main source of heat was a single steam boiler that was unreliable, inefficient, and required frequent maintenance. Comfort complaints were commonplace, including lack of heat during the coldest days of winter and inadequate user controllability. Conversely, because Fire Station 2 had no mechanical cooling, its fire fighters often reported having difficulty resting between calls in the summer.
As requested by the battalion chief, the new HVAC system had to provide both heating and cooling, and would also need to provide the fire fighters with control over their individual comfort levels.
The historical character of the building is one of the outstanding strengths of the project, but also presented several key design challenges. The existing façade was not to be altered; the deep concrete beams left little ceiling clearance for modern HVAC needs; and the wooden roof structure was incapable of supporting any large equipment.
The station’s location in a residential neighborhood added another layer of complexity. Because the station operated 24 hours a day, it would have to comply with the most stringent noise ordinance in the Seattle municipal code, 45 dBA measured at the adjacent residential property lines just a short distance to the north, west, and south. The new HVAC systems would have to be located on the roof without triggering a structural upgrade, and without creating a noise problem.
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