Project profile: VA Ambulatory Care Center
A three-level outpatient healthcare facility for military veterans, encompassing about 157,000 square feet.
Engineering firm: LEO A DALY
2021 MEP Giants rank: 98
Project: Omaha VA Ambulatory Care Center
Location: Omaha, NE, United States
Building type: Hospital/health care facility
Project type: New construction
Engineering services: Automation, controls; electrical, power; energy, sustainability; fire, life safety; HVAC, mechanical; lighting; plumbing, piping
Project timeline: August 2017 to August 2020
MEP/FP budget: $1,180,000
This is a three-level outpatient healthcare facility for military veterans, encompassing about 157,000 square feet. Engineering challenges essentially fell into three categories. For example, some challenges stemmed from the need for seamless architectural integration within a premium aesthetic context. Other challenges were driven by the owner’s requirements for future adaptability. Lastly, most veterans healthcare projects follow prescriptive specifications to meet a standard performance level. With this being a first-of-its kind healthcare project for veterans, driven simultaneously by the public and private sectors, stakeholder input from doctors, nurses and administrators led to non-standard, performance-driven mechanical and electrical specifications.
Surgeons often prefer very-cool temperatures in operating rooms. For this project, they requested lower-than-standard temperatures. Achieving this while maintaining humidification and pressurization requirements presented a challenge.
Before and during design, the client was in the process of evaluating multiple future utility upgrade projects for their campus. One option they were considering was chilled-water from an outside utility to meet campus cooling loads. Mechanical infrastructure needed to offer the flexibility of future outside-utility tie-ins whose construction would not interrupt daily healthcare operations.
Symbolic architectural features were designed to honor the veterans who would one day occupy the facility as patients. These features included a curtain wall that now forms the facility’s northern façade. The glass wall emulates the appearance of an American flag rippling in the wind. Interior of the wall is the waiting area for seven primary-care clinics. Maintaining thermal comfort in such close proximity to extensive glazing presented challenges.
Another architectural feature is a symbolic limestone wall, which separates public spaces from secure clinical areas. The wall is composed of layers of sediment, which symbolize the foreign soil tracked home from conflicts and alternating eras of peace and war. Challenges for lighting arose from the wall’s placement between clinical spaces and most sources of daylighting, which was otherwise harvested extensively throughout the facility.
An interior limestone wall serves to separate secure, clinical spaces housed in the core from public areas around the perimeter. The public areas make extensive use of natural daylighting but clinical areas lack the same access to natural light. In clinical spaces, designers specified a protocol of automated controls and tunable white luminaires to provide a sense of the passage of time. The lighting color temperatures automatically change throughout the day, imitating the warmth of morning daylight, cooling through midday and warming again in late afternoon.
The mechanical design incorporated a packaged chilled-water cooling plant located just north of an existing central boiler-plant facility. By designing chilled-water infrastructure as an independent, self-contained plant and locating it near the proposed routing of future utilities, the plant can be bypassed in the future if the client decides to draw chilled water from a separate utility connection. And these changes can be accomplished without construction interrupting daily healthcare operations.
In operating rooms, to meet staff requests for lower-than-standard temperatures, designers specified a desiccant dehumidification wheel for the operating room air-handling units. They deliberately selected a desiccant material that leverages differences in relative humidity rather than requiring increased energy to heat it, which helped the facility meet LEED Silver energy criteria. To that same end, air supply and return in operating rooms use pressure-independent air valves capable of resetting to lower airflows when the rooms are unoccupied – always without impacting pressurization requirements.
Throughout the facility, architectural soffits house ductwork and radiant heating panels. The colors, shapes and routing of soffits resulted from collaboration between architects, interior designers and mechanical engineers. This collaboration allowed for the placement of heating and cooling elements in waiting areas along the north curtain wall in order to maintain thermal comfort without detracting from the user experience of the space.
The lighting design throughout the facility uses a combination of direct and indirect lighting to provide visual comfort and even illumination. Linear suspended lighting in the core staff work areas is edge-lit to shield the light source and reduce glare. The extensive use of LED lighting reduces the connected lighting load to better-than-code. All lighting is standard dimmable, and automated controls balance electric output with daylight harvesting.
The intersecting linear slot lighting in the lobby follows the same lines as the signature curtain wall, enhancing visual interest in the space by continuing the lines of the architectural façade. Linear wall-wash luminaires continuously graze the limestone wall with light, accentuating its texture and illuminating original artworks.
An interior monumental stair occupies space near the building entryway across from a polished limestone wall emblazoned with the names of the building’s benefactors. Wall washers draw attention to the text and reveal the beauty of the stone. Above the stair, semi-recessed linear slot lighting evenly illuminates the space. Designers specified linear slot luminaires with a drop lens to throw light horizontally and highlight wood features in the ceiling.
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