Enhancing patient care and energy efficiency in hospital electrical design

Electrical and power insights

• Increasing demands for resiliency in healthcare facilities drive design choices like relocating power systems above floodplains and incorporating robust, flexible emergency power plants or microgrids with cogeneration capabilities.
• Human-centric and dynamic lighting designs enhance task performance and adapt to circadian rhythms.

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Respondents: 

• Cory Duggin, PE, LEED AP BD+C, BEMP, Principal / Senior Energy Wizard, TLC Engineering Solutions, Brentwood, Tenn.
• Benjamin Medich, PE, Vice president, HDR, Pennington, N.J.
• Daniel Noto, PE, LEED AP, Southeast market leader, Fitzemeyer and Tocci Associates, Alpharetta, Ga.
• Kevin Jayne, PE, LEED AP, Principal. Affiliated Engineers, Inc., Denver, Colo.

Describe any issues unique to designing electrical/power systems for hospitals or health care facilities.

Benjamin Medich: The electrical system for hospitals is unique unto itself per NFPA 70: National Electrical Code (NEC), Article 517. Beyond the emergency and selective coordination requirements that are specific to hospitals, there are regulations around the use of isolated power systems in wet procedure locations that are not unique to hospitals, but also potentially different between healthcare systems and locations.

Under NFPA 99: Health Care Facilities Code and NEC 517, patient care areas are divided into categories. Category 1 (formerly Critical Care) has the most stringent requirements. Typical Category 1 rooms include intensive care unit rooms and operatories. Category 2 (formerly General Care) has somewhat relaxed requirements in comparison and includes med-surg rooms and typical patient bed locations. Category 3 represents basic clinical care (ie, general exam rooms) and Category 4 refers to support, or “back of house” areas.  These categories impact the type and quantity of wiring devices needed, circuiting and raceway requirements, and power source requirements.

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?

Benjamin Medich: Moving normal and emergency power systems above the floodplain contributes to resiliency. While this requires more architectural coordination than burying systems in a sub-basement, it is necessary for service and resiliency reasons.

Owners also desire emergency power systems that are increasingly robust and flexible. Implementing an emergency power plant that can support most of the hospital’s operations, or in some cases, cogeneration systems that can support all of them, is a consideration that is becoming more appealing. However, larger systems can burn a significant amount of fuel. Having the flexibility to take units on and offline helps to limit the necessary fuel storage on site.

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

Benjamin Medich: One of current challenge is the lead in time for equipment. Lead times for switchgear and transformers can be in excess of one year. Beyond design issues here, It is imperative that there be a method to obtain this equipment in the event of failure without leaving the hospital single-ended for a year or more.

Additionally, the faster-acting air circuit breakers that are now in close proximity to the step-down transformers can cause transient overvoltage problems on switching operations that can damage equipment. In these cases, consideration must be given to snubbers, transient voltage resistant transformers and other methods to mitigate the effects of the switching transients.

The space constraints of medium voltage systems differ from those specified in NEC 110.26, requiring adherence to NEC 110.31 and 110.34. These constraints become more restrictive as utility service voltages increase.  In retrofit projects, the voltage currently available from the utility may align with the existing equipment, requiring more complex re-work to connect the existing systems to the new voltage.

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

Benjamin Medich: The key differences are generally outlined in NFPA 70: National Electrical Code (NEC) Article 517. Healthcare facilities need separate branches of emergency power (critical emergency vs. life safety emergency) in addition to the non-emergency equipment branches. This creates a more complex and versatile system to run through short and long utility disturbances.

For existing buildings, the International Conference on Robotics and Automation considerations change the scope considerably. Designing systems to minimize impact to other areas is critical to keep the facility operating smoothly and minimizing the cost of future changes. Mechanical and electrical systems that are not “contained” can lead to a more significant shutdown of building spaces to keep infection control procedures in place during construction, which can be more costly, time consuming and disruptive to the staff and patients.

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?

Benjamin Medich: Awareness of the importance quality lighting on patient wellness has grown tremendously. Because of this, we have long had a dedicated team of lighting design professionals collaborating on our projects. Lighting needs to support both visual and physiological needs. Illumination calculations alone are no longer sufficient. Our lighting designers work very closely with architects and clients to provide solutions that enhance interior design aesthetics, support intuitive wayfinding, accommodate speed and accuracy of task performance, enhance physical health and wellbeing, reduce maintenance burdens and conserve energy.

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?

Kevin Jayne: From an energy efficiency perspective, what once required justification for transitioning to LED lighting is now simply standard practice. This trend applies to other engineering system assessments that have also become commonplace to comply with increasingly stringent energy codes. As lighting control systems advance, modern design can leverage daylight harvesting in hospitals to maximize available natural light. Additionally, these systems can offer tunable color temperatures, allowing patients to adjust their environment or utilize a more human-centric lighting control system that supports circadian rhythms.

Daniel Noto: It is important to balance the client’s current needs with future flexibility. Almost every project space will eventually be renovated, expanded or have its use changed. An electrical system that allows for that change in use and/or capacity will save the owner time and money in the future when those changes are needed.

Benjamin Medich: As an integrated architecture engineering firm, we are able to craft a coordinated and flexible solution early on in a project that enables us to seamlessly integrate the utility backbone space, which is necessary to assure flexibility. We discuss the future and the rationale behind utility flex considerations with the owner’s rep and the construction manager to ensure that the project goals are fully understood. This ensures that future considerations are not simply treated as “empty space” and are used in an approach that promotes flexibility.  Early engagement of all parties is crucial to the success of the entire team.

Are you seeing more smart- or microgrid aspects on such projects? If so, how have you served these needs?

Benjamin Medich: We have seen an increase in micro-grid applications, particularly with cogeneration equipment. Machines that were originally designed to operate in parallel with utilities are now being programmed to black start and operate independently of the grid. As facilities prepare for the impacts of climate change, these considerations are becoming more prevalent.

What kind of lighting designs have you incorporated into a health care project, either for energy efficiency or to increase the occupant’s experience? Discuss the use of human-centric lighting or other lighting techniques.

Benjamin Medich: We have implemented dynamic lighting systems to enhance circadian support and integrated lighting control capabilities into patient controllers; providing patients a sense of autonomy. Patient controller options are rapidly changing from push buttons, which limited control, to touch pads that are infinitely configurable. These touch pads not only control the room environment but also access patient records and treatment plans, order food and use the internet.

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?

Benjamin Medich: Lighting design requirements vary by space type. ANSI/IES Standard RP-29: Recommended Practice: Lighting Hospital Healthcare Facilities is an excellent resource. Items such as horizontal and vertical illumination, uniformity, flicker and glare reduction, surface brightness, color quality, intuitive use of controls, energy usage reduction, ease of maintainability, system reliability and flexibility, contrast ratios and surface reflectance are all factors that require consideration after understanding how the room will be used and by whom.

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