Project profile: High-capacity cabling for neonatal intensive care unit
Project name: University of Maryland Children’s Hospital neonatal intensive care unit cable system replacement
Project type: System overhaul
Building type: Hospitals/health care facilities
Timeline: July 2014 – May 2015
The new neonatal intensive care unit (NICU) is a 37,612 gross sq ft unit on the fourth floor of the North Building on the University of Maryland Medical Center campus. Products specified to satisfy the cabling needs were flexible hand bendable cable tray and basket style high capacity cable tray. The design was incorporated into the electrical drawings to facilitate installation by the electrical contractor. The new NICU substantially expanded capacity and improved patient accommodations. The old NICU had 40 patient care spaces organized into five patient care areas in a 12,500 +/- sq ft unit in South Hospital. Four areas were ward-like rooms with seven patients per room allocated according diagnostic/treatment specialty. The fifth area was the step-down area, a suite of adjoining rooms for 12 more mature babies. Before the new space, volume at the NICU was 500 patients per year, with an average stay of 27 days, and a 95% occupancy rate. The new NICU has 52 patient care spaces in a 37,612 gross sq ft unit, with anticipated volume of 713 patients per year by 2022 with an average stay of 25.3 days and a 95% occupancy rate.
The unit is a level 4 NICU. The space has very limited space above the ceilings in the corridors, with only about 2.5 ft available for all utility runs above the suspended ceiling.
The plans for the new unit, all on one floor, called for 1,600 cables with an average length of about 125 ft. The farthest room has cable runs of about 250 ft. The NICU integrates decentralized nursing, rather than traditional nursing stations in patient care areas and relies on wireless handsets for exchange of data among physicians, nurses, and researchers, with constant communication available 24/7. Nurses work in their patients’ rooms and adjoining spaces, never more than a dozen steps from their charges. All patient rooms have charting PCs, with additional PCs between each set of two rooms. Each patient room has 16 cables servicing IT and clinical equipment with full Wi-Fi coverage, with three additional cables in the adjacent corridor servicing the room. And as more technology is brought into the patient room—and despite the prevalence of wireless technology in health care—cable counts could increase. The security, stability, and capacity of cable for fixed equipment and mobile equipment in NICU settings is preferred. Also, the communications installation needs to support activation of about 600 outlets in the initial start-up.
The low ceiling height in the corridors limits flexibility and prohibited the use of cable tray support trapezes. This created a challenge for laying/managing the cable. Deck to deck is 12 ft. Deck to beam is 10.5 ft. Patient room ceiling height is 8.5 ft. Corridor ceiling heights are 8 ft. North Hospital was built in 1970 and attaches to South Hospital, the oldest Medical Center building, built in 1937. The floors were made to align, so ceiling space was restricted to the 1937 elevations. Because the installation is in a hospital, all the air is ducted supply and return. The main corridors have 36 and 40 in. wide HVAC ducts, medical gas pipes, electrical distribution, plumbing and sprinkler piping, and the hospital pneumatic tube system. In an 8 ft wide corridor, there is very little open space for cable tray.
The university’s medical center uses ladder-style cable tray in the telecommunications room to support cables and tie racks together, which requires horizontal cables and patch cords sharing a common tray, a configuration that could evolve into overhead spaghetti and which the engineers wanted to avoid.
The NICU cabling installation used two distinct styles of cable tray from Snake Tray, a manufacturer of cable management and power/data transmission solutions. The cable management system uses 404 ft hand bendable cable tray in staff spaces and in smaller corridors and 575 ft of high capacity pre-configured basket-style tray for overhead applications in the major corridors. Because the deck heights are low and trapezes would have require too much space, the installation needed straight cable runs that could snake around others and a cable support system that could handle 1,000+ patch cords.
Patient treatment areas are piped from corridors to tray. Work areas use limited J-hooks to connect the cable systems with the rooms. The flexibility of the cable tray was very advantageous in making field adjustments around other trades, including accommodating unexpected pipe valves, fittings, and other objects. The cable tray is reachable and adjustable for additions or future changes in cabling, unlike traditional basket-style cable tray, which would be more difficult to adjust.
The ability to drill tubular retaining posts on ladder tray to mount wall snake in front of the above-rack ladder tray enabled separating out patch cords from horizontal cables, facilitated a cleaner installation than older, traditional methods of installation.
Two strong considerations factored into the specifying of Snake Tray products. First, in corridors with basket style cable tray, a place with clearances down to inches, Snake Tray afforded the ability to easily attach tray directly to threaded rods without the use of additional hardware or trapezes, which frees up much needed space. Secondly, in the lower cable count areas, the use of flexible Snake Tray products enables installing a continuous pathway supporting the cables, avoiding the risk of cable sag between J-hook supports where, when space is tight, the cables could end up resting on T-bars or other utilities. Snake Tray provides the desired separation in areas where pathways intertwine.
By using basket-style cable tray directly attached to support rods and flexible cable tray, installers were able to work around tight areas and minimize impact of the installation on other systems.