For Healthcare, Children Deserve the Best
Children's Hospital in Omaha, Neb., has been caring for children since 1948. In fact, it is the only strictly pediatric hospital within a 200-mi. radius. Omaha-based HDR has provided architecture and engineering services to the facility since the early 1970s, on projects ranging from master plans and facility upgrades to the recent design of a replacement hospital.
Children’s Hospital in Omaha, Neb., has been caring for children since 1948. In fact, it is the only strictly pediatric hospital within a 200-mi. radius. Omaha-based HDR has provided architecture and engineering services to the facility since the early 1970s, on projects ranging from master plans and facility upgrades to the recent design of a replacement hospital.
With a unique football shape and 275,000 sq. ft. of space, the facility opened in October 2000 and is in its final stages of completion. With nine floors, the facility boasts three medical surgical floors, each with 24 single-occupancy rooms. There is also a 16-bed pediatric intensive care unit and a 31-bed neonatal intensive care unit.
The new hospital consolidates functions, allows expansion of essential services and helps create new services. The exterior relies on a whimsical and playful design to convey that this is a children’s facility, and the interior design, as well, is intended to create a healing environment for children.
This advanced healthcare facility demanded nothing less than state-of-the-art engineered system designs. For the power systems, this was accomplished in several ways.
Power, normal and standby
For primary power, utility power feeds two 3,200-amp switchboards. Insulated-case draw-out circuit breakers provide the hospital flexibility to maintain the system without a complete switchboard outage, and minimize down time by rolling in a spare breaker to serve the load in the event of a breaker failure. Separate lighting and power bus extend vertically through the building to serve lighting and 120-volt power loads separately.
The emergency power system is powered by three 600-kW generators that feed a paralleling switchgear bus, which feeds the emergency side of the automatic transfer switches (ATS). Upon loss of utility power, all three generators start and synchronize to the emergency bus and carry the emergency load in 10 seconds.
The ATS equipment transfers in an order prescribed by National Electrical Code (NEC) 517 to feed the emergency loads. In addition to feeding the standard loads typically fed by emergency power in a hospital, the Children’s system has the capacity to support specific radiology equipment, as well as one chiller and its supporting pumps.
Paralleling the generators on a common bus provides many advantages. First, the generator system is more accurately sized to support the large chiller and radiology loads. If only one genset were dedicated to the chiller loads, it would have to be sized significantly greater than the load in order to start the large motors.
Likewise, if one generator were dedicated to the radiology load, the genset would have to be well oversized to provide a stable electrical source for this type of equipment’s high-energy pulse demands. At the facility, multiple generators on a common bus provide the rotating mass necessary to start and operate these loads.
The second advantage of a common bus is that if one generator is inoperable, due to maintenance or an outage, the remaining two generators can carry most of the hospital’s emergency load. The intelligence in the paralleling switchgear will not allow the chiller loads to transfer to emergency power (see “Don’t Pardon the Interruption” CSE 04/02 p.40 for more on central UPS schemes).
Finally, the Joint Commission on Accreditation of Healthcare Organizations requires each generator to be loaded to 30% of its nameplate each month. Each generator can be tested individually, with the other two generators disconnected from the bus.
Throughout the facility, three levels of transient-voltage surge suppression are included on specific switchboards and panelboards, most of which also include a power meter. Distribution panels have a power-quality meter, and lighting panels are equipped with an electronic ammeter. The power monitoring system is networked to a central computer in the plant maintenance office for monitoring power quality and power consumption at any level within the facility.
To mitigate power problems where they start, an extensive grounding system was designed. A ground grid of bare 4/0-AWG copper was installed under all the electrical, generator and main communications rooms. A 4/0-AWG copper ring surrounds the building.
The main grounding system is connected to a main electrical grounding bus (MEGB) in the main electrical room. All connections, designed per NEC standards, terminate to this MEGB. Each electrical room on each level includes a grounding bus bar that connects this riser system to building steel and to the building water pipe. The telecommunications grounding riser is connected to the MEGB and was designed per Telecommunications Industry Association (TIA) standards.
State-of-the-art electrical design carried over to the lighting. For increased efficiency, user-friendliness and safety, lighting system designers utilized several of the latest technologies, including high-output T5 lamps with a lumen output almost equal to two conventional T8s, but with less energy consumption.
Dimming systems in all patient floor corridors are designed to give a lower ambient light level during the evening hours and incur energy savings from the decreased output. The variation of illumination from 100% to 50% is completed over a 30-minute period, unnoticed by hospital personnel and patients. The evenly dimmed corridor light distribution provides a pleasant environment when walking the corridor and reading patient charts. Control of lighting for all commons areas, the parking garage and exterior lighting is performed through the dimming system with photocell and time clock on/off.
In addition, fiber-optic lighting is used in many areas of the hospital for accent lighting of special features. Fiber optic was used, instead of neon and cold cathode, because of ease of maintenance, color-changing capabilities and public safety—many of the applications are within reach of little hands. The fiber only carries the light, which originates at a hidden illuminator at each end of the fiber. No current is passed through it, so it is safe to touch or grab. End-emitting fiber provides the lighting effects for “twinkling star ceilings,” while side-emitting fiber is used for backlighting stained glass in the chapel and highlighting coves in the lobby. And it’s even used to produce waves of rainbow colors as a distraction for children during a particular radiology procedure.
Final touches to the lighting system include the following:
Parabolic and indirect troffers provide low-glare lighting on CRT screens.
Fluorescent downlights with dimming capability provide user flexibility in radiology, nuclear medicine and ultrasound rooms.
Motion detectors in public toilets and open storage areas shut off the lights during low-use times.
LED exit signs are ultra-efficient energy consumers.
Indirect dimmable lighting wall fixtures, along with quartz downlight, are used in neonatal intensive care for exam purposes.
Part of the team
The design of Children’s Hospital was definitely a team effort that included not only the building team, but other concerned parties as well. Building designers held multiple user-group meetings with nurses and doctors. Mockup rooms were constructed for surgery, emergency, trauma, intensive care and patient rooms. It was a thorough process, and HDR’s electrical and lighting designers were an essential part from start to finish.