Consulting-Specifying Engineer - June 2008 - (Page 33)

////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////// Photo: Karlsberger Architects have even taken steps to bring their grandfathered facilities up to modern code. • Developing a “hardened shelter” within the hospital building itself, which one coastal hospital has done. The philosophy is “bend, don’t break.” During the highest category storms (when the first floor could be flooded and the windows blown out), they withdraw patients and staff to an interior space that has dedicated heating, power, and communications; the rest of the hospital shuts down to prevent short-circuiting and other catastrophic infrastructure failures. Engineers face two major challenges in upgrading the power at a hospital: service interruption and scalability. Service interruption is the single most daunting challenge, because a hospital cannot tolerate any interruption of service. Often, new electrical systems must be built in parallel with an existing system with a single tie-in/changeover date. Electrical systems for healthcare often are designed to accommodate life-safety issues rather than first-cost criteria. The only thing sure about hospitals is that they will grow— often much faster than healthcare clients realize. Any design that doesn’t anticipate a large addition within five years is shortsighted. In the following project case studies, all from U.S. locales that are likely to experience natural disasters, disaster planning played a key part in the project design and decisionmaking process. Florida: All Children’s Hospital Florida has long been a magnet for hurricanes forming in the Atlantic Ocean, and most healthcare administrators in Florida can attest to the importance of hurricane preparedness and provide real-life examples and gripping first-person accounts. This is why when All Children’s Hospital in St. Petersburg planned to build a new 10story children’s hospital and central plant, administrators made disaster preparedness a top priority. The heart of the hospital’s disaster preparedness plan, the central plant, is designed to withstand Category 5 hurricane winds and any storm surge that might flood the first floor. The boilers, chillers, and normal service switchboards are all located on the second floor, and the third floor houses the emergency power system and the cooling towers. All openings to the exterior are protected by louvers or doors that have been tested to withstand the impact of a flying 2x4 moving at 150 mph. In a hurricane, the breaching of a door or window can allow winds, water, and flying debris to wreak havoc on a building’s interior; in the case of a home, it could be enough to lift the roof from below. All Children’s central plant is designed to include three chillers and associated pumps, with the peak usage being slightly more than two chillers until shell areas are filled out. The emergency power system is designed to completely back up everything in the hospital and in the plant. Furthermore, the emergency system is split into two systems—A and B— each of which includes a parallel switchgear and three 2-MW generators, for a total of 12 MW of emergency power. Of the 12 MW of emergency power, 8 MW can be running in 10 sec., suitable for all Priority 1 essential loads. Figure 1 is a one-line drawing of the B side generator system. All too often, the evaluation of a hospital or central plant results in too many “if only” statements: If only the prior design had allowed for expansion to the building; if only the generator was one size larger; if only the chiller piping was one size larger. Staff at All Children’s, aware of these concerns, determined that the new hospital plant needed to be designed for expansion so that it could serve future as well as current needs. The entire facility is designed with enough infrastructure to double in capacity, including all piping, wire, and distribution. The current building layout includes N+1 redundancy, plus housekeeping pads for a second for a second normal service, a fourth chiller, two additional generators, and an additional boiler. In addition, the building master plan includes a future horizontal Run longer, run cleaner In the quest for greater sustainability, even hospital emergency power systems are being greened. One South Florida hospital system has incorporated a natural-gassupplemented fuel source to all of its new and existing generators. This bi-fuel system has the primary benefit of reducing fuel oil consumption by using as much as a 50/50 mixture of fuel oil and natural gas, thus extending up to 100% the potential available run time of the system (i.e., from three days fuel storage to six days) without increased on-site storage of fuel oil. With the rising costs of fuel oil, the treatment costs of stockpiling ever larger quantities to meet longer outages, and the sheer capital costs of large or additional fuel oil tanks, the system offers real savings and can be retrofitted to most existing generators. The green benefit, of course, is much cleaner emissions when running in the mixed-fuel mode. Hospitals also are looking at bio-diesel fuel as a part of their pushes for reducing their impacts on the environment. Running a mixture of bio-diesel and petro-diesel can greatly reduce the particulate emissions level of generators. A few caveats: Bio-diesel can be more troublesome in very cold weather, can be aggressive to natural rubber components such as may be in the fuel system, and may result in higher nitrous oxide (smog-producing) emissions. Consult with the generator manufacturer to ensure that a unit is configured or capable of being modified for bio-diesel. Consulting-Specifying Engineer • JUNE 2008 33

Table of Contents Feed for the Digital Edition of Consulting-Specifying Engineer - June 2008

Consulting-Specifying Engineer - June 2008 Contents Viewpoint Letters News M/E Roundtable No Gambling Allowed on Smoke Control in Las Vegas Be Prepared: Hospital Protections for Catastrophic Events Ready for Retail Commissioning Documents: Necessary Evil Codes & Standards Codes & Standards Case Study Equipment Lifecycles New Products Advertiser Index Green Space

Consulting-Specifying Engineer - June 2008

For optimal viewing of this digital publication, please enable JavaScript and then refresh the page. If you would like to try to load the digital publication without using Flash Player detection, please click here.