Ask an expert: Hospitals, health care facilities: Electrical and lighting systems

Health care facility designers are expected to keep pace with increasingly complex, advanced engineered systems and features

By Consulting-Specifying Engineer November 19, 2019


Neal Boothe

TLC Engineering Solutions

Boothe has more than 24 years of experience in the health care industry. As Principal/Senior Electrical Engineer, he has led numerous projects, including new greenfield hospitals and additions and renovations to existing health care facilities.

Mark Chrisman

Henderson Engineers

In his role as Vice Presidentand Health care Practice Director, Chrisman coordinates strategy for the company’s health care projects nationwide. His areas of technical expertise include fire protection and code consulting.

Tom Divine

Johnston, LLC

As Senior Electrical Engineer, Divine has spent 21 years in the consulting engineering field, with the past 17 years designing and engineering health care facilities. He is responsible for power, lighting and fire alarm design for hospital and health care projects.

Roger Koppenheffer

Certus Consulting Engineers

As a founding Principal of Certus Consulting Engineers, Koppenheffer brings 24 years of experience in the MEP consulting engineering industry specializing in health care facilities. He has a range of expertise in mechanical and plumbing engineering.

Nick Martin

Affiliated Engineers Inc.

As principal, Martin oversees multidiscipline engineering teams with a focus on national and international health care markets. He originally joined the firm as an electrical project engineer.

Michael Phillips

Southland Industries/Envise

Phillips works with consulting engineers, customers and internal business development staff. He is responsible for educating them on the solutions offered through controls and building automation.

Jose Torres

RMF Engineering

As Health care Team Leader in the company’s North Carolina Building Systems Division, Torres works with organizations such as Duke Health, UNC Hospitals and Rex Health care. He has been with RMF since January 2001.

April Woods


As vice president and mechanical department head of Florida building systems for the company, Woods has played a key role in engineering mechanical solutions for major health care projects. She has facilitated sustainable design for several successful green building projects.

CSE: Are there any issues unique to designing electrical/power systems for these types of facilities?

Divine: Reliability is the watchword for hospital electrical systems. That’s accomplished with standby generation systems, paralleled generators and multiple utility feeders. Locations are carefully selected to avoid hazards. Hospital systems also enjoy special dispensations in the codes: generators may be sized based on demand load rather than connected load to avoid wet stacking and essential systems may be designed with a relaxed requirement for selective coordination, as compared to emergency systems, to allow for a balance between selectivity and protection functions.

Martin: Capacities for electrical systems in health care has always been a topic of discussion. In the past, many of these systems were simply over-designed because there wasn’t a comprehensive understanding of how real-world loads would impact electrical infrastructure. With a focus on energy-saving methods and equipment along with evidence-based design, we have been able to fine-tune electrical/power system capacities for design without going overboard and adding unnecessary costs.

Boothe: From a design perspective, we provide additional safeguards in our design to increase system reliability. We typically design all our hospitals with a redundant generator (an N+1 generator system) so that in case of loss of any generator the hospital can maintain all required loads. Furthermore, we typically go beyond code minimums when placing equipment on generator power. For example, code requires air handling units in areas like ORs, patient rooms, intensive care units, emergency departments and other patient care areas to be on generator power but it doesn’t require this for ancillary hospital areas such as Administration and back of house areas. However, we typically design all air handling systems hospitalwide to be on generator power. Also, we design generator fuel capacity to allow for a minimum of 96 hours of more of available diesel fuel for generators.

Koppenheffer: Designing health care electrical systems is unique because there are countless nuances buried within the plethora of codes that must go into every design. Among these include division of the emergency power system into three distinct branches with maintained separation from other circuits. Two levels of ground fault protection, normal and critical bonding, redundant grounding, mechanical protection of emergency circuits and hospital grade receptacles are all requirements detailed in the codes. All of these and many more are dictated by codes and standards and must be fully understood and implemented when designing health care electrical power systems.

CSE: What types of unusual standby, emergency or backup power systems have you specified for such facilities?

Koppenheffer: The trend over the past decade has been to include more equipment and devices on emergency power, substantially beyond code minimums. However, this is countered with tighter budgets and less space for equipment. One project challenge was to provide a large hospital campus with 100% emergency power backup. Short of over-sizing the generator plant to match the incoming utility, the team used its extensive experience in the design of hospital emergency power systems to apply some innovative strategies to meet the project goals within the allotted budget and space constraints. Codes require sizing based on prudent demand factors and connected loads, but also allow for engineering judgement to meet the capacity of the actual anticipated demands using historical data. The team’s understanding of real-world expectations on system operation allowed for a right-sized design with a manual means to back feed the normal power to the facility. A high degree of power monitoring was included to allow the trained facility engineer to implement the system during an extended power outage.

CSE: In the aftermath of several recent severe weather events, owners of such projects are increasingly interested in electrical/power resiliency features. How are you meeting these demands?

Boothe: Our company does a great number of hospital facilities in the state of Florida and, therefore, in areas susceptible to hurricane damage. TheFlorida Building Code(which is Florida’s modification of the International Building Code) does a lot to enhance hospitals in Florida to prepare them for hurricanes and other natural disasters. For example, the Florida Building Code requires that either an exterior connection device be installed at each new hospital (to allow connection to a portable generator during an extended power outage) or that the emergency electrical system include a separate transfer switch connected to the hospital generators to power the hospital’s normal power (the power not code required to be on generator power) from the generator system so that the hospital can run more efficiently during an extended power outage.

Divine: Our clients are concerned about flooding and wind associated with tropical storms. We call for major normal and standby power system components to be installed well above the 500-year flood plain and for two or more utility feeders where the utility system configuration and the project budget allow for it.

Woods: As weather patterns continue to reveal the vulnerability of our infrastructure systems, the need for highly resilient on-site power generation and fuel storage will continue to be a unique requirement that health care facilities must operate and maintain. Each project requirements for the emergency power system is evaluated for its resiliency and ability to meet the facilities risk management and emergency preparedness plan, which may be above and beyond minimum code requirements. This is particularly relevant in Florida and other coastal regions where the threat of hurricanes can lead to long-term power outages and other devastating effects.

Martin: Owners in coastal areas recently affected by hurricanes have started to take a much closer look at the right location for electrical infrastructure within a building. Traditionally, service entrance equipment and generators were located in a lower level of a building where they were out of the way of valuable revenue-generating patient care spaces. However, when the water table starts to rise, these lower areas are the first to flood. Owners in coastal areas are now executing plans to move this type of infrastructure and equipment out of the flood plain and above high-water marks to ensure that they don’t fail during a flooding event.

Koppenheffer: Consideration and elimination of single points of failure are some key factors in resiliency planning. Designing for resiliency goes hand-in-hand in designing for redundancy, however redundancy alone is not enough. Location planning and feeder routing are crucial for true resilient design. Locating equipment in multiple locations and routing redundant feeders with different paths aid in achieving resiliency goals. Additional considerations we may look at are locating the emergency power supply systemon an upper level to provide flood-proofing or indoors to protect against high winds. If the equipment is located outdoors, consideration is given not only to lateral protection, but also protection from above from human malicious attempts of damaging equipment through the open-air of a generator yard or through vulnerable louvers.

CSE: What are some of the challenges when designing high-voltage power systems in hospitals, health care facilities and medical campus projects?

Koppenheffer: Medium-voltagepower systems are a great application for large and complex campuses. One of the main challenges with designing these systems are the additional space requirements. MV substations require more space than their 480-volt counterparts because the transformers are essentially being moved indoors. In addition, the equipment requires more clearances to meet NEC due to their higher operating voltage. An additional challenge frequently encountered is the fear of the unknown. Many facility engineers are unfamiliar with MV operating systems or the maintenance and servicing requirements and are therefore leery of these systems. Education in these instances is key and when performing the initial cost analysis to determine the best service voltage, it may be prudent to account for an initial investment in training.

CSE: What kind of maintenance guidelines are involved to ensure the project is running efficiently after the project is finished?

Koppenheffer: Once the building is turned over and the hospital is responsible for the continued maintenance, regular testing of all systems should be performed. Performing monthly tests of the EPSS is required by NFPA to keep up with compliance reporting, but programs should also include preventive maintenance such as periodic exercising of circuit breaker and components according to the manufacturer’s recommendations. Investing in annual infrared scanning of terminations could identify potential points of failure or loose terminations. The power monitoring systems, when understood and used properly, may also be used as a predictive maintenance tool. Monitoring high power users and sensitive electronics such as large variable frequency drives, imaging modalities, surgery, central sterile and similar departments could reveal power fluctuations or disturbances, which can be logged and used to predict when equipment is nearing the end of life or needs attention.

CSE: What are some key differences in electrical, lighting and power systems you might incorporate in this kind of facility, compared to other projects?

Martin: In health care, particularly for high acuity facilities, electrical systems need to be resilient and flexible. Systems need to have the ability to automatically (or manually) be re-energized in the event of a failure. Likewise, systems need to remain energized in adjacent occupied spaces during a renovation. Multiple layers of reliability are built into these systems to allow for constant operation and flexibility during times of renovation.

Koppenheffer: Branch circuit wiring within a health care facility for lighting and power is subject to many strict requirements compared to other types of facilities. The wiring of different branches must be kept entirely independent from each other, there must be a redundant ground path in all circuits that serve patient care areas and the emergency circuits must be mechanically protected. Another major differentiator for health care systems is the use of isolated power systems. An isolated power system is an ungrounded system used in wet locations, primarily in operating rooms. There are only five electrical power circuits noted in the NEC where the code committee has determined the hazards of an ungrounded system outweigh safety benefits of grounding and this is one of those systems, which is unique to health care facilities.

CSE: Studies show the quality and type of lighting in such facilities may impact patient wellness and recovery time. How, if at all, is your team taking that concept into consideration with your designs?

Woods: It has been well revealed through studies that health outcomes and productivity are deeply influenced by light. At our company, we continue to use the latest lighting research to calibrate circadian rhythms and visual acuity. We carefully balance the integration of daylight and electric lighting to enhance the user experience, circadian stimulus and control for time of day changes.

Phillips: We are an advocate for installing LED fixtures as controlled devices that can respond and produce different types of light wavelengths according to the application. The control of lighting needs to be brought front and center into the overall patient experience.

Koppenheffer: There are major trends in health care for tunable white lighting to support the circadian response and enhance patient wellness. These systems continue to undergo studies to fully determine if they have an effect on enhanced patient outcomes and designing these systems for hospitals is complex at best. Unlike office buildings where human-centric lighting is becoming common practice, there are many unique lighting requirements in a hospital required to support the medical tasks that can’t be overlooked. A recent project included the use of tunable white lighting within the neonatal intensive care unitwhere tunable fixtures were designed to interact with controls system to mimic outdoor conditions. Additionally, each room included an override control so the medical staff could easily switch the fixtures to full brightness and high color temperature best to perform an exam or task. After the tasks are complete, the override times out and the tunable controls revert to the daylight simulation program.

Martin: We have been implementing more and more lighting designs in patient care areas that are predicated on an understanding of circadian rhythms within the daily cycle. It is an approach based on fact and it’s exciting to have the opportunity to educate our clients on the science behind the design and see it implemented. Our in-house specialty lighting group, Pivotal Lighting Design, has been at the forefront of this topic and specializes in assisting clients understand the benefits of various lighting approaches to patient care.

Boothe: For our lighting systems, we will take steps to minimize the impact of unwanted lighting around patients. For example, in an emergency department corridor where patients will be on stretchers lying toward the ceiling, we will design indirect lighting systems so they aren’t exposed to direct lighting in their eyes. As a second example, we will design corridors down patient care wings to allow for reduced lighting levels at night. This allows the staff to reduce the lighting levels (simulate a more nighttime feel on the patient wing) to the extent possible to help patients sleep. There are some codes that affect our lighting design for patient wellness also. For example, the Guidelines for Design and Construction of Hospitalsand similar guidelines for outpatient facilities requires the use of indirect lighting in NICU areas.

CSE: How does your team work with the architect, owner’s rep and other project team members so the electrical/power systems are flexible and sustainable?

Martin: Working with our partners to ensure they understand how these systems operate, what levels of reliability are being incorporated and when they are needed is key to ensuring the end result really works. Exotic electrical systems with multiple devices switching back and forth automatically can present an operational headache when there is a failure in normal power because there can be too many moving parts that aren’t fully understood. When such designs are required, there needs to be a thorough educational process with the facilities team to ensure that they know how to operate the system. The most exotic electrical system in the world won’t do anyone any good if they don’t know how it is supposed to be operated in the time of need.

Koppenheffer: Our goal is to right-size the electrical systems and work closely with the facility stakeholders to understand their needs and deliver a project that meets them. Oversizing a generator will cause maintenance problems such as wet stacking, but under-sizing the system could cause unnecessary downtime or damage to equipment. Future-proofing the systems includes building in expansion capabilities and reserving space for future equipment. It includes specifying infrared viewing windows to facilitate ongoing preventive maintenance and scanning without exposing personnel to dangerous arc flash by opening energized equipment. It involves working closely with the architects to ensure that electrical rooms stack on each floor to allow for a path for future conduits and feeder risers for the equipment of tomorrow’s medical facilities that does not yet exist.

CSE: What kind of lighting designs have you incorporated into a health care project, either for energy efficiency or to increase the occupant’s experience?

Koppenheffer: Due to the advances in solid-state lighting, there are now far-reaching capabilities to use lighting to achieve many goals such as energy savings and sustainability, improved productivity and patient outcomes, visual acuity and even enhancing the mood of the occupants. Using LED, we can use higher Kelvin temperatures to better mimic daylight and extremely high color rendering to enhance medical staff visual acuity allowing them to better perform intricate tasks associated with health care. We can also affordably employ color changing and interactive displays for specialty hospitals such as children’s facilities enhancing the human-centric experience. These benefits coupled with the fact that they have a long life and low operating costs, make using LED a preferred choice when it comes to health care lighting design.

CSE: When designing lighting systems for these types of structures, what design factors are being requested? Are there any particular technical advantages that are or need to be considered?

Divine: Nearly all of our clients want LED lighting throughout their facilities, for its performance, controllability and low maintenance requirements. We’re seeing requests for color-tunable lighting and for more patient controls in patient sleeping rooms. We often design full-color digital multiplex-controlled lighting displays in imaging rooms, to entertain and divert pediatric patients during imaging procedures.

Phillips: What is the best way to integrate the lighting into the improved patient experience? Will the patient be able to control the lighting locally, through an app or other device? How will it be presented? What other features or systems along with lighting can the patient easily interface with? Are there IoT considerations?

Koppenheffer: Increasing the occupant experience is tied directly to patient satisfaction and lighting plays an important role in this. Providing the patient with full control of their own environment is a great way to achieve this goal. A recent project included the use of integrating the lighting controls with other systems in the patient room to provide maximum control over their environment directly from the patient bed. The integrated systems included lighting controls, nurse call, temperature controls and even window shade controls. Integration such as this requires close coordination with all team members — owner, design, construction and vendor — to ensure the systems provide the desired outcome. On this project, several live mock-ups were built to ensure all the components operated properly before implementation.

Martin: It seems like a minor detail, but in the patient care setting, we really need to be thoughtful with where controls are located with respect to staff and the patient. Some things need to be controlled by staff from a location where they won’t interrupt the patient. Likewise, the patient needs to be able to have control over specific lighting elements as well.