Operating on medical and hospital projects: electrical/lighting/power
Larry Anderson, PE, RCDD, CDT, Principal, TEECOM, Oakland, Calif.
Jeremy Jones, PE, LEED AP, EDAC , Healthcare Market Leader, Affiliated Engineers Inc., Chapel Hill, N.C.
Daniel S. Noto, PE, LEED AP BD+C, Healthcare Studio Leader-Southeast Region, exp, Atlanta
Eric Reuther, PE, LEED AP BD+C, Principal, McClure Engineering Associates Inc., St. Louis
Jonathan B. Slagel, PE, LEED AP, HFDP, Principal/Vice President York Office & Healthcare, Barton Associates Inc., York, Pa.
Bill Talbert, PE, BEMP, LEED AP, Senior Mechanical Engineer, MEP Associates LLC, Verona, Wis.
CSE: Describe a recent electrical/power system challenge you encountered when working on a hospital or medical campus project, such as a building with offices, labs, exam rooms, operating rooms, etc.
Reuther: After a big storm that left one of our hospital clients without power for 4 days, the owner decided to invest in a new emergency power system. We installed two 1-MW generators in a remote building across the street from the hospital, with space for a third generator as the hospital grows. The building was designed with special considerations to withstand a large storm to protect the generators.
During the previous storm, the hospital learned that emergency cooling was a high priority so a new 900-ton chilled-water plant functioning on emergency power also was housed in this building with the generators. The power and chilled-water pipes were routed underground across the street and connected to the main hospital systems.
One of the biggest challenges was meeting the city’s requirements for sound levels as this building was surrounded by a residential neighborhood. To meet the acoustic requirements, water-cooled generators had to be used rather than the typical air-cooled machines, which would allow too much noise in and out of the building. The cooling towers in the adjacent chilled-water plant were over-sized to pick up the load of the generators. To meet the acoustic requirements, the towers had to be designed with large fans running at slower speeds to keep the sound levels down. The towers also were installed with concrete walls around them to protect the equipment in the event of a storm.
Slagel: During a recent surgery suite expansion and renovation project, an issue arose during construction where an existing main critical branch breaker tripped while electricians were working on the 277 V lighting circuits in the operating rooms. The main breaker supplied critical branch power to the existing, functional operating rooms as well as to the pre-operation and recovery bays, which means the nuisance trips were a huge issue. The initial assessment was that the breaker tripped on a short-circuit due to lack of coordination between the trip curves with downstream distribution panel breakers. After digging into the situation further, including onsite verification of the breaker in question, it was identified that the existing breaker was actually installed with ground-fault protection. It should be noted that, for the particular breaker type in question, the inclusion of ground-fault protection cannot be verified through noninvasive visual inspection. The only way we were able to confirm the situation was to work with the hospital’s electricians to have the cover of the distribution board removed following appropriate arc flash precautions. Following this discovery, it was determined that the breaker tripped due to a ground fault and not an overcurrent event. NFPA 70: National Electrical Code prohibits inclusion of ground-fault protection on any breakers in a critical branch power system that are downstream of the automatic transfer switch. The reasons are obvious in this case, as a fault on an individual lighting circuit should not be able to take down the entire critical branch service to an operating suite. We worked with the owner and contractor to identify short-term adjustments to the ground-fault settings to minimize the risk of additional trips until a service shutdown could be scheduled to permanently remove the ground-fault protection device.
CSE: How do you work with the architect, owner, and other project team members to make the electrical/power system both flexible and sustainable at the same time?
Slagel: Developing a flexible and sustainable campus approach to power requires close coordination and detailed planning with all parties involved in the project, especially the owner and architect. It is critical to open dialogue with the owner at the onset of a project involving significant power infrastructure work-to identify any existing gaps or concerns with the system as well as any future project or building plans that may require capacity in the future. With a clear picture of the present state, requirements of the immediate project, and future campus requirements, the design team can plan a holistic approach to the power distribution system that can maintain existing critical functions in service while laying the groundwork for future projects. Solid planning on the front end can save a multitude of headaches and cost for the owner in the long run. It is also crucial to include the architect in the planning discussions so that adequate space can be allocated in the project program for electrical-distribution gear in appropriate locations. This step must happen early, during the preliminary or schematic design phase, as it becomes very difficult to obtain additional space after floor plans are set and approved by clinical staff and hospital leadership.
CSE: Is LED lighting in high demand from hospital or medical campus facilities? If so, describe a recent lighting design project.
Jones: Several years ago, LED was most prevalent in retrofit projects where hospitals received incentives from their utility provider for energy efficiency projects, or when CFOs allowed system upgrades based on lifecycle analysis. I believe we have finally reached the tipping point: LED costs have dropped to the point where LED is a common basis of design on new projects, even without incentives. In fact, on almost every recent greenfield or major renovation project we’ve issued, LED has been the basis of design.
Slagel: Over the past several years, we have seen a gradual increase in the demand and affordability of LED lighting for hospital and medical campuses. In addition to lowering price points, LED manufacturers continue to develop new product lines that provide a broad array of lighting solutions and color quality that make them very conducive to the health care environment. Over the past 2 years, we have seen multiple projects where owners who requested two lighting design bids (one for predominant fluorescent lighting and an alternate bid for an equivalent LED package) found that LED priced out very comparably to fluorescent lighting packages. The application and cost of LED fixtures, along with their inherent flexibility for integration with dimming controls or addressable lighting control systems, have led us to a point where LED fixtures are the norm for almost all of our health care projects. The increasing use of LED lighting is also a significant benefit for health care facilities as they significantly reduce operating costs for traditional fluorescent lamps, which helps facility managers meet stringent goals to reduce energy consumption and costs for campuses. Another option that LED lighting provides is the ability to incorporate tunable white-light controls in patient and staff environments. While this technology is relatively new in the United States, it has been used for years in Europe, where numerous studies indicate that the use of tunable white lighting supports the natural circadian cycle of humans. Tunable white lighting varies the color output of the fixtures to mimic the changes in the light spectrum produced by natural sunlight, which drives the body’s natural production of melatonin, a key component to restful sleep. While the premium for this type of system is not insignificant, the potential benefits to overall patient and staff health may soon drive a demand for this type of system in the health care environment.
CSE: Describe a recent standby, emergency, or backup power system you designed and its challenges and solutions.
Slagel: We are currently working with a regional health care client who is focusing on significant campus emergency power upgrades. Through load-capacity studies completed over the past several years, we helped the client identify that their current emergency power systems are nearing capacity and would not be able to support future campus growth. Additionally, the existing generation system is fragmented and does not provide any level of redundancy for the critical campus power systems. After investigating options to upgrade/expand the campus’ emergency power generation capacity, the owner elected to take the solution one step further and provide backup power for the entire health care campus. The solution will entail a generator "farm" in which all of the generators are designated for level 1 service as defined by NFPA 110: Standard for Emergency and Standby Power Systems. The integrated, generator-control system brings an initial stage of generators on within the required 10-second duration to support the essential power system loads. For an extended power outage, the generator controls (with input from the facility team) can bring on additional generators to backfeed the normal power service of the entire campus. Under these conditions, the hospital campus will have a full complement of power to maintain normal operations. The generator farm also includes aboveground fuel storage to provide a minimum of 96 hours of run time at full load to comply with the most current emergency-preparedness requirements.
CSE: Are hospital and medical campus clients requesting addressable lighting systems? If so, describe the project.
Slagel: We have seen an increasing demand and use of addressable lighting systems within the health care arena. Addressable lighting systems provide many benefits to the clinical team as well as the hospital facility group. One of the greatest benefits is the level of control flexibility these systems can provide. The low-voltage switches can be programmed and reprogrammed to perform different lighting functions or lighting levels as the needs of the space change and adapt over time. An example of this could be lighting in a medical-surgical or intensive care nursing unit, where the staff wants the ability to incorporate a lower level of lighting in common areas during evening hours to minimize disruption to the sleep cycle of their patients. Standard lighting control design would set up two levels of lighting based on theoretical calculations, which may be close but not fully representative of the final space use. With an addressable system that incorporates dimmable LED fixtures, the facility team has the ability to adjust the nighttime light levels in the corridors to suit the specific needs of the nursing staff and make adjustments to those light-level settings over time. Addressable lighting systems also provide great flexibility as spaces are renovated over time, as low-voltage lighting controls can easily be relocated to accommodate new room configurations or different lighting-scheme requirements.
CSE: Technology is having a huge impact on facility design. Describe a project in which technology played a large role, such as receptacles, circuit length, wireless Internet in patient rooms, etc.
Anderson: Parkland Memorial Hospital’s technological approach is designed around the idea that technology can improve the quality of health care. Every high-tech, high-touch, Voice over Internet Protocol (VoIP) telephone has a camera and a screen. When a nurse answers a patient’s call, the two can see and hear each other. A digital, energy-efficient, Power over Ethernet sign outside of each inpatient room identifies the patient, doctor, and nurse, along with individual care guides. Inpatient rooms feature monitors that display customized meal plans and health information and serve as the video and audio hub of the room. In ICUs, smart beds monitor 18 data points and notify caregivers when something is wrong. In Parkland Memorial Hospital’s new operating suites, advanced video capability helps surgeons during operations and can be used as an educational tool with the patient’s consent.