By Susan Rochford et al.
from the July/August 2015 issue
As the high performance building movement has evolved and matured, so have the design disciplines that are essential to delivering building operations and functionality. This evolution is not only occurring within each design area—such as mechanical, electrical, or security, but also across all trades with increasing interaction and interdependency.
The electrical system—and the physical infrastructure that enables it—is a central component in the design and operation of a high performance building. This complex system is rapidly changing in response to technology and marketplace developments.
A new set of principles is emerging that can serve as the basis for electrical system design when striving to optimize a building’s performance on multiple fronts. The key principles are:
- Employ life cycle planning.
- Focus on the occupant.
- Enable device connectivity.
- Embrace IT and open systems.
- Harvest system data.
The High Performance Movement
The last few decades witnessed a steady evolution of thought and practice in building design and construction. The high performance building movement began in the 1970s as concerns began to emerge about workplace productivity, and it grew in the 1980s and 1990s as energy efficiency and other sustainability issues gained currency in the design community. The movement accelerated in the 21st century.
While defining a concept as encompassing as a high performance building is challenging, the federal government articulated a clear vision in the Energy Independence and Security Act (EISA) of 2007. According to that legislation, a high performance building is one that “integrates and optimizes on a life cycle basis all major high performance attributes, including energy conservation, environment, safety, security, durability, accessibility, cost-benefit, productivity, sustainability, functionality, and operational considerations.”1
Importance Of Whole Building Design
To achieve the vision of high performance and to meet the expanding needs within the built environment, a holistic approach to building design is known as “whole building design.”2 It consists of two major components: integrated design approach and integrated team process.
At its heart, the integrated design approach embraces all stakeholders in the building process as early as possible to join in ongoing collaboration, rather than the conventional approach of relying on specialists with focused expertise working in isolation from one another.
The second component of whole building design focuses on the project team dynamic, in which the design team and all affected stakeholders collaborate throughout the design process. By drawing upon the expertise of this entire community, the project then gains the benefit of multifaceted perspectives not only in the design phase, but also in other phases of the building life cycle, such as construction and operations.
Once involved in the project team, vendors may be expected to play a more proactive role in meeting the design intent. For example, they might provide Building Information Modeling (BIM) objects, replacing construction drawings with project specific shop drawings and supporting new approaches to implementing the vision while working within the construction restraints of time, space, and cost.
This trend is becoming particularly evident in the realm of electrical system design, as these systems are highly configurable and are often prefabricated off-site. The electrical system is:
- composed of a wide range of low and high voltage devices, wiring, cabling, and connectors that deliver electrical power, including wireless power for inductive charging, safely and reliably;
- the source of tens of thousands of the data points that inform and shape building performance; and
- a key enabler to achieving the potential of demand response.
New technology means that today’s electrical system is increasingly sophisticated. It is essential to the delivery of vital building services, including lighting, communications, alarm and life safety systems, heating, ventilation, and cooling as well as all forms of equipment and is connected to a burgeoning number of Internet of Things (IoT) devices supplying big data.
Five Emerging Principles For Electrical Systems
Advances in electrical system design are enabling a profound transformation in building performance. Realizing these benefits requires recognition that new principles are needed to guide the design process.
Principle #1: Employ Life Cycle Planning. As a project team approaches the electrical systems design, keeping the building life cycle squarely in mind provides the greatest opportunity to realize the most robust vision for high performance. This requires a deep understanding of the facility users’ needs, the intended mission of the building and its many spaces, and an intuitive appreciation for how the built environment will be used across its own lifespan.
In one example, Parkland Hospital in Dallas, TX—the largest public hospital in the U.S.—is employing life cycle planning as an integral part of its new hospital construction. Scheduled to open in August 2015 the renovated hospital will provide state-of-the-art healthcare in a facility expected to achieve LEED Silver certification.
Some of the statistics on the 2.1 million square foot project provide context to the scale of the facility. To deliver to its more than one million patient visits each year, the new hospital features:
- 865 private adult beds
- 58 labor delivery rooms
- 120 emergency exam rooms
- 10 trauma rooms
- 27 surgery suites
- 575 miles of conduit
- More than 32,000 light fixtures
- More than 42,000 data outlets
- Nearly 900 cameras
- 45 elevators
- More than 1,500 miles of copper data cabling
To achieve its vision for high performance, the Parkland Hospital project team employed modeling as a vital part of its life cycle planning. While many high performance buildings projects use BIM, the Parkland team moved beyond computerized modeling and constructed extensive full-scale mockups to test design concepts and usability and make product and vendor selections.
MC Dean, the design-assist and systems integration firm responsible for the new Parkland Hospital electrical system, pioneered the Pre-installation Testing and Check Out (PITCO) process for networked systems and used the mockup process to support prefabrication.
To facilitate the electrical systems design at Parkland, 10,000 square feet of patient care and surgical areas were modeled. One design nuance identified during this phase was the need to calibrate the controls to work efficiently with every light source. Because LED fixture drivers respond differently to standard low voltage control signaling, control of light and energy usage can fluctuate up to 20% if using an uncalibrated control system. By commissioning the controls for each fixture type to ensure linear performance, centralized commands will accurately deliver the desired light conditions and energy savings. This is important during both normal and emergency operations, as the ability to reduce the lighting load accurately during a power outage minimizes the need for capital spending on generators and other emergency infrastructure.
In addition, the modular assembly and pre-testing of the lighting control system allows the lighting to be scheduled off after hours, providing energy cost savings during the construction cycle and once the facility is operational.
“I can’t think of any reason why you wouldn’t want to do it,” observes Jerry Nickerson, senior vice president of engineering and controls for Parkland Hospital. “Mockups like this offer the opportunity to fine-tune a range of operational functions that will reap benefits throughout the entire lifespan of the hospital.”
Principle #2: Focus on the Occupant. Traditionally not a major factor in electrical infrastructure design for conventional buildings, the needs of building occupants have become an essential consideration in high performance building design. Understanding how different occupants use different spaces in a facility can help the design team make more informed decisions earlier in the process, saving resources from the construction phase through the operations phase of the building life cycle.
For example, during the Parkland mockup, vendors observed that caregiver evaluators were uncomfortable using touchscreens at workstations or in patient rooms.
“In many cases they didn’t object to the technology, but they preferred more simplicity in their work environment,” comments Pete Horton, vice president market development for WattStopper. “Rather than having to spend 30 seconds concentrating on how to use the interface, they wanted the ability to activate lighting immediately so they could focus on the patient.”
This led the team to develop engraved switch buttons that clearly identified programmed light levels “at-a-glance” for caregivers and patients alike. Switch buttons were also color-coded so users could immediately and intuitively distinguish ordinary lighting (white) from emergency lighting (red).
Principle #3: Enable Device Connectivity. In order to capture data from building systems, the high performance facility must connect a wide variety of devices across the built environment including edge devices such as lighting fixtures, sensors, switches, and receptacles. If the distributed devices include intrinsic intelligence, they will be capable of withstanding external or network failures, including server, Ethernet, or Internet failure.
Connectivity can be established via wired or wireless networks. Both have advantages and disadvantages, so project teams should assess the particular needs of the project. Often, a combination of wired and wireless proves to be the optimal solution. Wired connectivity for interior spaces often reduces the initial investment for control devices, while wireless solutions for connecting remote buildings can be the most practical and least resource intensive.
New energy code requirements are also are driving additional monitoring and control of electrical products and systems. ASHRAE 90.1-2010 and -2013 require automatic shut-off of designated plug receptacles in many commercial areas.
In Boston, MA, the new Liberty Mutual Headquarters building recently complied with these requirements by installing more than 700 receptacle controllers connected to both lighting occupancy sensors and building management system (BMS). This digital control network solution automatically turns off controlled receptacles when the space is vacant and reports energy use per square foot to the BMS. Liberty Mutual selected open protocol systems communicating via BACnet protocol over the IP network to manage energy use without the need for a second IP network and provide visibility into ongoing operations. Robust IP networks are critical for handling the big data that is generated by modern lighting control systems.
At Parkland Hospital in Dallas, there are:
- 63,000 lighting control devices, monitored every 15 minutes;
- 2.2 billion data points accumulated per year;
- one trended data point per 35 square feet; and
- one data point available for configuration and monitoring per five square feet.
Principle #4: Embrace IT and Open Systems. In high performance buildings, electrical and IT and cloud infrastructures are rapidly converging. The use of open source protocols ensures that electrical systems can more effectively integrate with other building systems, rather than operate in individual silos.
The key advantage to convergence is the ability to aggregate, evaluate, and deliver actionable information to facility management professionals anywhere, and in any format. This enables organizations to manage building data from disparate systems across multiple locations using shared applications in a hosted environment. This architecture delivers additional benefits including reducing capital expenditure on IT infrastructure and support, while increasing scalability to address new organizational challenges such as sustainability, predictive maintenance and asset management3.
Increasingly, electrical manufacturers are supporting IP protocols, taking advantage of the IT infrastructure and software to compete with traditional electrical components. The ability to use existing IT frameworks is also enabling real-time monitoring and reporting of energy performance data.
Principle #5: Harvest System Data. With the electrical and IT infrastructure in place, and when equipped with the appropriate analytical tools, facility managers can monitor a wide range of performance indicators. These can include trending and reporting energy performance, but these data can also inform facility decision makers and operators about many other important facets of building operations, such as water consumption, indoor air quality, and space utilization.
Actionable energy information across many different space types needs to be normalized and categorized. For the Liberty Mutual facility in Boston, both the lighting and plug load power is measured in watts per square foot (W/ft2). This provides instantaneous measurement of how different spaces are performing. Energy consumption (watt-hours) is also recorded every 15 minutes for each space. Facility managers can graph energy (watt-hours) per square foot by space type over time, with an option to compare against similar or different space types.
Meanwhile, data visualization tools continue to evolve. Early and current generation dashboards have relied on tree- or map-based interfaces, which serve up data in context with a linear project framework or a floor plan view (example shown on opposite page). While helpful, these interfaces demonstrate limitations, particularly in the flexible, rapidly changing environments of high performance buildings. Tree-based interfaces can be confusing to scale. Floor plan views require intensive customized graphical coding that can be rendered obsolete upon the next tenant’s improvements or workplace reconfiguration.
Emerging visualization tools emphasize intuitive data “tiles” that can be grouped functionally, geographically, or in other meaningful arrangements depending on specific application. As shown above, this format has been successfully used in other data-intensive settings, such as the financial industry where stock and commodity market information must stream continuously to enable real-time interpretation and action.
The evolution of high performance building design continues to evolve with each new generation of building sustainability codes; the many policy drivers aimed at addressing myriad social, economic, and environmental challenges; and the transformative market technologies that allow a convergence of building system capabilities.
These forces are shaping advances in electrical infrastructure design and installation. The five principles discussed in this article are among those advances that facility executives should address with project partners.
The next steps for many building designers will include integrating key card access with systems including lighting and HVAC, both for occupant comfort but also to improve building security—a mission critical aspect of building performance.
These benefits illustrate just some of the reasons that facility owners are reaping greater returns on investments in high performance buildings. As the expectation for constant connectivity to more systems and data increases, costs for networked solutions will continue to drop. This strengthens the case for integrated systems and design—and underscores the important role of electrical system design as a factor in achieving building performance objectives.
1. “Energy Independence and Security Act of 2007,” (U.S. Government: GPO) Title IV – Energy Savings in Buildings and Industry, Section 401, Definitions
2. Don Prowler, FAIA, revised and updated by Stephanie Vierra, Assoc. AIA, LEED AP BD+C, “Whole Building Design” (National Institute of Building Sciences: Whole Building Design Guide, March 22, 2012)
3. Greg Turner, “BAS-IT Convergence, Now and Into the Cloud” (automatedbuildings.com, April 2010)
This article was adapted from a white paper published in October 2014 by Legrand, “The New Dynamic of High Performance Buildings: Advanced Electrical Design Principles in Practice.” The full paper can be accessed here. The paper was co-authored by Susan Rochford, vice president, energy efficiency, sustainability, and public policy, Legrand North America; Evelyne McLeland, director of marketing, WattStopper; Shana Longo, sustainability and government affairs analyst, Legrand North America; Pete Horton, vice president market development, WattStopper; and Rita Renner, director, marketing & communications, WattStopper.