Engineered Systems - February 2008 - (Page 43) Anyone can claim to go the distance. Technologies currently available for the built environment offer tremendous value d l opportunities that are many times unsuccessfully implemented. Typical design and l i d procurement processes for (MEP) systems limit the designer’s ability to take advantage of available innovation and integration opportunities. dancy, reliability, maintainability, and future capacity for growth. Major systems such as chilled water, heating water, steam, normal electrical service, and emergency electrical service were all provided with standby/redundant equipment, so that in the event of a failure of a single piece of equipment, the facility would not have a loss of services. System capacity for future growth was accomplished by allocating space for equipment to be installed in the future as hospital growth warranted the expenditure. Allocating space for future equipment also meant allocating equipment delivery and move-in paths. In addition, the distribution infrastructure had to be installed to allow for the installation and connection of the future equipment without shutdown of these systems. Next came the difficult question of how much present capacity and future capacity is required. Having lost the all-knowing crystal ball, the owner and the design team participated in development sessions to determine where the facility will be on opening day and where the facility will be in 10 to 20 years. As most people involved in this process would tell you, it would be easy to resolve this issue with an unlimited budget; however, we had to make the best use of present and future capital. As with any hospital and laboratory operation, electrical power service was a highly discussed subject, especially after the Northeast Blackout of 2003. The CHP campus is supplied power by three Duquesne Light Company (DLCo.) transformers, fed by three separate service grids interconnected by a 5-kV ring-bus. Any two of the three transformers can supply enough power to operate the entire facility. Because the facility’s electrical system is energized under emergency power through the normal power circuits, almost all of the mechanical equipment in the CSB, central plant, and research laboratory building is capable of being supplied with emergency power. This affords some unique operational characteristics for the CHP facility. The mechanical systems take advantage of this electrical system design by integrating the BAS into the operation of the emergency power system. The BAS receives a signal from the electrical system to indicate the number of DLCo. service transformers and the number of generators that are operating. Based on the information provided by the electrical system, the BAS determines how many chillers, boilers, pumps, AHUs, and other mechanical equipment to operate based on an extensive priority table. Almost all of the mechanical equipment has been installed with VFDs. This design feature enhances the mechanical system operation on emergency power. In advance of load shedding by shutting down equipment, the BAS can reduce loads by operating equipment at reduced speed, and thus at reduced capacity. Implementing VFDs also reduces the electrical starting requirements of the generators. This design allows more of the facility to operate under adverse conditions as propagated by the Northeast Blackout of 2003. Another advantage of this design is that everything happens automatically, providing the facilities operating staff with time to assemble their game plan for a short or prolonged outage. In addition, the BAS affords the operating staff the ability to manually alter the emergency operating characteristics of the facility based on building occupancy, weather, and other factors once the system operation has stabilized. As the design criteria moved from the central cooling, heating, and power generation systems to the end service equipment, complete redundancy was not going to be cost-effective AERCO. Built better to last longer. Benchmark Boilers. Proven technologies and superior materials make the difference. Twenty years of high-efficiency experience go into every unit we sell. Designed and warranted for condensing operation and thermal shock, AERCO utilizes stainless steel fireside materials for superior corrosion resistance and unmatchable performance … year after year. To learn more visit www.aerco.com/bm4 Copyright 2008 AERCO International, Inc. Heat You Can Bank On FREE INFO: 72 w w w. esmag a zin e. c o m ESM02084AERO.indd 1 43 1/16/08 1:33:29 PM http://www.aerco.com/bm4 http://www.aerco.com/bm4 http://www.esmagazine.com
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