High-Performance Building Systems: Mechanical, Electrical, and Controls Systems

August 28, 2008 |

High-Performance Building Systems: Mechanical, Electrical, and Controls Systems (Continued from p. 68 of the September 2008 issue of BD+C)

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Reed Business Information is a Registered Provider with the American Institute of Architects Continuing Education Systems. Credit earned on completion of this program will be reported to CES Records for AIA members. Certificates of Completion for non-AIA members are available on request.

       This program is registered with the AIA/CES for continuing professional education. As such, it does not include content that may be deemed or construed to be an approval or endorsement by the AIA of any material of construction or any method or manner of handling, using, distributing, or dealing in any material or product. Questions related to specific materials, methods, and services will be addressed at the conclusion of this presentation. 

Another key component in lighting systems is the ballast. In recent years, electronic ballasts have largely replaced electromagnetic designs, leveraging higher light output, better color rendering, reduced lamp flicker, and much less noise.

A relatively new player in the market is the digitally addressable ballast, which can both simplify lighting systems and reduce costs. “These systems still require thoughtful design, and there is some programming involved, but they are almost becoming ‘plug-and-play,’” according to Frank Klusek, P.E., LEED AP, principal and chief electrical engineer, KlingStubbins, Philadelphia. Adds Daniel E. Edenbaum, LC, lighting design chief with KlingStubbins, “Light and control functions are assigned with handheld programmers during final commissioning, taking a lot of the guesswork out of the system. And changes simply require reprogramming, not new wiring.”

On the Meter: Power Monitoring
One area of electrical system design that has really taken off in sophistication and application range is power metering and monitoring. Driven by the LEED rating system, rising energy costs, and various technological advances, the installation and use of power meters is at an all-time high.

“With an ever-growing ‘green’ society, most owners are concerned about energy consumption, so more and more clients are installing submeters to monitor energy usage,” notes Michael Weingartz, P.E., principal and discipline director of electrical engineering for SmithGroup. “This information allows building owners to monitor usage, generate trends, and, in some cases, determine fees for users to offset energy costs.”

Submetering can also provide building owners with the data necessary to identify systems that are not operating as expected and to optimize their performance over the lifetime of the building, says KlingStubbins’ Klusek. In fact, the Energy Policy Act of 2005, known as EPAct, actually requires advanced metering in all federal buildings, which means that the meters must measure consumption on an interval basis and then communicate those measurements at least once a day.

As for the U.S. Green Building Council’s LEED rating system, submetering can help qualify a building for a credit called Measurement and Verification of Energy Savings. “This LEED credit, EA Credit 5, is attained by accounting for building energy consumption over time and evaluating the actual energy savings of high-efficiency equipment and subsystems against the projected energy usage of a baseline subsystem,” says Klusek. 

“Metering and monitoring are blossoming in the industry and can now be performed at very sophisticated levels.” says Rajan Battish, P.E., principal of RTKL’s Applied Technology Group. “We can now do wave capture with a 1-millisecond time stamp, which was not commercially possible in recent history. The metering can be performed to circuit level with servers to help understand the true load of the facility, as well as identify inefficiencies of the system and methods for more effective load management.” According to Battish, new software lets building engineers simulate failure modes and transfer schemes prior to performing maintenance. Wave capture is also useful in performing forensic analysis if any M/E/P systems fail.

A number of these monitoring-and-metering technologies are now Web-enabled, making energy usage data from the meter available not only to facilities personnel but also to building tenants, occupants, and other interested parties.

“Some state-of-the-art meters allow access on a meter-by-meter basis, while other systems interface the meters to a PC-based software package, which can provide Web-based access to charts, trends, or even consolidated ‘energy dashboard’ statistics,” says Klusek. “Some manufacturers even offer conversion of display units from electrical consumption units to tons of CO2 or other key sustainability indicators.”

Choosing the right metering technology is largely driven by whether the project is new construction or retrofit. “New construction provides the benefit of cost-effective, intelligent metering integrated with switchgear and switchboards,” says Klusek. “Retrofit applications often rely on standalone submeters with split-core current transducers or current sensors to keep installation costs and shutdown durations low.”

As for overall effectiveness, “Although central metering and monitoring are popular, there seems to be a trend toward distributed systems, which can be used more critically for cost allocation as well as preventive maintenance,” says Dominick J. Pastore, P.E., LEED AP, a VP with SmithGroup, Detroit.

Double Duty: Cogeneration

Another distributed technology making waves in building designs is cogeneration and distributed generation (DG). A number of key variables must be evaluated before determining if DG makes sense for a particular project, says KlingStubbins’ Klusek, the technology has been proven to “provide substantial benefits to building owners, including reduced fuel costs for separate steam and hot-water generation systems”—through the use of combined heat-and-power, or CHP, systems. These systems “increase reliability, improve power quality, lower exposure to electric utility price increases, and [generate] potential revenues from selling excess generation back to the grid,” according to Klusek.

RTKL’s Battish also sees the appeal of distributed generation increasing as a result of the limitations on today’s electrical infrastructure and the escalating costs of energy. Both electricity providers and users can benefit from it.

“Distributed generation benefits utilities and grid operators through preserving capacity in existing generation and transmission infrastructure,” says Klusek. “Increasing electric utility rates due to removal of utility rate caps, the promise of clean, reliable on-site power, and advances in small-scale power generation technology have combined to increase the number of building owners and designers considering DG in building projects.”

Distributed generation comes in many forms nowadays, notes Klusek, including solar photovoltaic, passive solar, wind, geothermal, reciprocating engine generators, and natural gas-fired fuel cells and microturbines.

SmithGroup’s Weingartz has seen growing interest and application of microturbines, a technology he says enables “continuous, 10-year uninterruptible clean power with relatively low maintenance and the option to use the waste heat for the mechanical systems.” Drawbacks of microturbine technology, however, include the high initial cost of the systems and the relatively small amount of power that can be generated, measured in kilowatts (kW).

As for solar photovoltaic, wind power, and geothermal systems, SmithGroup’s Pastore sees a rise in application, typically for smaller systems under 10,000 kW to augment traditional systems. He adds, however, that “more funding and incentives are needed to continue the technology development and to help shift the public paradigm.”

In addition to the availability of incentives such as tax credits, rebates, and subsidies, a number of other factors must be carefully evaluated in order to determine whether distributed generation is viable for a particular project. These include the following:

• Is there a use for both the electricity and waste heat?

• What is the local price of electricity and natural gas?

• Are there local ordinances concerning emissions and noise?

• How cooperative will the local utility be regarding connection to the grid?

• Is there sufficient space for an on-site system?

Unlimited Uptime: Using UPS

Although uninterruptible power supply (UPS) systems don’t offer much in the way of energy efficiency, these failsafe backup battery arrays and generation systems have been a critical component of emergency power, especially for sensitive loads such as data centers, hospitals, and financial institutions. However, when it comes to balancing the benefits of redundancy with initial cost, it can be quite a delicate act.

“Systems can become very complex, which typically drives up the cost, which means higher-paid and more skilled maintenance personnel are required,” says electrical engineer Weingartz. “I prefer to keep UPS systems simple and easy to maintain.” Pastore concurs with this advice, adding that the most important tip for specifying UPS systems is to keep it simple for the application. “More complexity and redundancy are not always better, even if cost were not an issue,” he notes.

At the same time, the fact remains that differing data and back-up needs, as well as varying load levels and conditions, will dictate a wide variety of UPS configurations. Briefly outlining the various standard configurations, Mark Hoskins, electrical engineering manager with Marshall Erdman & Associates, a healthcare facility design-build firm based in Madison, Wis., explains as follows:

• N – This describes the simplest, least expensive configuration, typically one double-conversion UPS with a maintenance bypass, requiring approximately two to four hours of annual downtime for scheduled preventive maintenance. Without redundancy, this configuration is vulnerable to several single points of failure.

• Isolated redundant or parallel redundant – Also called “N+1,” this configuration utilizes a single emergency generator and automatic transfer switch, affording an additional level of redundancy.

• Distributed redundant – This kind of UPS setup entails two utility power sources, an emergency generator, and multiple parallel and independent automatic transfer switches. The result is “nearly complete redundancy,” says Hoskins.

• System-plus-system redundant – Incorporating multiple utility sources, emergency generators, automatic transfer switches, UPS systems and power distribution units, this configuration virtually eliminates single points of failure, but comes at a high cost and space premium.

How can a Building Team know which of these configurations is best for a given application? “One of the basic issues to address when considering schematic-level UPS system design is to define the amount of dollar loss incurred during downtime caused by lack of computer-grade quality power,” says Klusek. “These losses must account for direct labor and productivity losses, possible IT equipment damage, restarting software and processes, in-process material loss, erroneous or lost data recovery, revenue losses, as well as lost business to competition and possible loss of reputation to customers. Once an estimate of dollar loss per outage time period is established, one can use a somewhat qualitative approach to balancing UPS redundancy and cost.”

By using the Uptime Institute’s Tier Classification system (http://uptimeinstitute.org), Building Teams and their clients can estimate the cost and average downtime and associated business costs related to the various UPS system schemes for different outages and emergency events. The “savings” in lost revenue by using a better UPS system can then be used in a life cycle cost analysis to justify the higher cost.

Ultimately, of course, the value of computer data and available servers is a qualitative estimate, which is in turn affected by such factors as building operations and maintenance. However, the schematic cost analysis is among the best ways to balance UPS redundancy and cost, say experts in electrical system design.

High-Performance Controls and BAS

While advanced and innovative M/E/P systems can go a long way toward cutting down operational costs and increasing overall efficiency, the building automation system (BAS) is an important component to enable it all to work. In fact, according to the Building Owners and Managers Association (BOMA) International Foundation and the U.S. Environmental Protection Agency, BAS has the potential to achieve a 30% reduction in energy use in the commercial real estate industry alone, essentially saving $7.2 billion annually. 

BAS has numerous benefits, including improved climate control, easier maintenance, and the need for less equipment. What makes BAS possible is the ability to access, view, and leverage operational data.

With a single-point access to building energy consumption and demand, BAS offers “the ability to make this information available to building managers and occupants in a powerful graphical format that lets them see the impact of their actions on energy use, energy costs, carbon emissions, and other key sustainability indicators,” says J. Alberto Rios, P.E., LEED AP, chief automation and controls engineer with KlingStubbins.

Tom Grimard, P.E., a senior controls specialist with Arup, based in New York, says, “The interoperability between systems facilitates collecting and archiving information about the built environment, energy consumption, and operational needs. This information can be analyzed to confirm that building systems are operating as designed, and to identify opportunities to improve operations.”

Mixing It Up with Interoperable Systems
Less than a decade ago, controls makers were warring over which communications protocols should be used in commercial facilities, rendering some M/E/P products incompatible.

“The design profession and the building industry have made great strides in building-systems interoperability and controls integration,” says Rios. “It has gotten to the point that you seldom have to ask M/E/P system vendors whether or not their systems are interoperable. Instead, you need to ask what communication protocols their systems use and what read/write points they offer.”

While the industry is certainly not at a point of full interoperability, key M/E/P components, such as variable-air-volume (VAV) boxes, chillers, boilers, and lighting controls are the most commonly integrated. “This is due to the fact that they must all work in concert to achieve an energy-efficient building,” explains Robert H. Smith, P.E., LEED AP, a mechanical controls design specialist with SmithGroup.

While integration with other building systems, such as daylighting and solar shading, may be desired, such features are often eliminated from building designs. “When the costs to implement are discovered, integration is often value-engineered out, unless there is a special need,” observes Garry Myers, P.E., vice president with Flack+Kurtz in New York.

In addition, though full systems integration is now technically possible, building owner preferences and local codes have generally kept the fire protection, security, and life-safety systems separate, although they are being designed to at least communicate with each other. “There is an interesting dichotomy in the realm of security, fire, and life safety,” says KlingStubbins’ Rios. “The vendors are ready to integrate, but many building owners and designers are not.”

Also limiting integration is the fact that fire protection and security systems are often handled by different facility personnel than the HVAC and lighting systems, notes Frost & Sullivan research analyst Sapan Agarwal. “IT personnel have little insight into BAS networks and communication while BAS installers often do not understand the intricacies of IT infrastructure,” says the Malaysia-based market analyst. “Despite the required technology in place, the low level of expertise in both domains is restraining convergence of IT and BAS.” (For more, see the Frost & Sullivan report, Strategic Analysis: Integration of Building Security Systems with BAS, at www.buildingtechnologies.frost.com.)

Even so, some inroads are being made as integrated systems such as fire/smoke dampers have created synergies between fire protection and HVAC systems.

And when interoperability is being specified, its capabilities in the realm of indoor environmental quality, or IEQ, are quite impressive. For instance, the ability to adjust the temperature, lighting, and airflow at the individual workstation level goes a long way in improving occupant comfort and employee satisfaction.

With regard to lighting controls, infrared or ultrasonic sensors used to dim or switch lights on an off based upon room occupancy deliver significant savings in energy use—a key provision for one of the largest electrical loads in commercial buildings. In fact, just by specifying dimming systems alone, average energy savings of 15-70% for offices and 30-75% for restrooms could be achieved, according to a University of Michigan Utilities and Plant Engineering study. Even in corridors, energy use was cut in half, according to the report.

BACnet vs. LonWorks

The two main protocols in use today are LonWorks and BACnet, according to Reka Szanto, a Frost & Sullivan analyst. “However, the building automation industry is not about choosing one protocol over the other. It is more about the best integration of the required systems.”

However, “The BACnet vs. Lon shootout is still alive and well,” says KlingStubbins’ Rios, who says that LonWorks has become the leading protocol for devices and components—for example, air-quality sensors and terminal unit controllers—while BACnet has greater penetration in the integration of major systems and equipment. Arup’s Grimard agrees with this assessment, adding that while LonWorks plays a critical role at the level of the device and control panel level, BACnet is seen as the ideal protocol for “integration and interoperability on the end-user level.”

In terms of choosing the best integration approach, it’s critical for Building Teams to be aware of client preferences and priorities. And sometimes the decision between BACnet and LonWorks may be based on the availability of building controls vendors and integrators in a project’s geographic area who may have experience in the given building type.

Coordination and Future-proofing

Regardless of communications protocol or the extent to which building systems are being integrated, the key to successful BAS schemes is coordination and collaboration among Building Team members (see sidebar, “BAS and the Building Team”). “Where a client/project requires interoperability between systems, it is critical that this requirement be understood, developed, and communicated to all members of the project team at the earliest stages of design,” states Grimard.

Similarly, Flack+Kurtz’s Myers points out that a detailed, written plan is vital in each phase of the process. “The integration planning must be designed as the project is designed,” he says. “There must be an agreed-upon integration plan that clearly describes the desired outcome of the proposed integration and the steps necessary to implement it.” For example, if the client wants to integrate an electrical metering system, the electrical distribution system must be designed with this in mind, as opposed to attempting to add the metering after the fact, he explains.

While some things can be planned and controlled by the Building Team, other things may be left to the unrelenting march of technology. While M/E/P and BAS systems are improving rapidly, unanticipated building industry advances are bound to materialize. To help Building Teams plan for the future, professional engineer and consultant Jim Sinopoli, managing principal of Smart Buildings, Spicewood, Texas, foresees the following:

• Major manufacturers of Ethernet network switches will add RS-485 and RS-422 network ports to switches to directly connect BAS systems to an internet protocol, or IP, backbone.

• Energy usage reporting will become more commonplace. These reports will be detailed, public, and eventually posted on a Website for all interested parties to examine.

• The sophisticated graphics and interfaces already developed for video games will find their way to BAS systems.

• The industry will see new “building system centers” that monitor and manage integrated systems as the cost effectiveness of the approach is simply too compelling to ignore.

• Global, real-time information systems for asset data and location will become a reality, as all the technologies required for such a system—real-time locator systems, building information modeling (BIM), and geospatial databases and tools such as Google Earth—are now available and awaiting integration.

Sinopoli’s last prediction could have a huge impact on building operations. It would essentially mean that a facility manager for a portfolio of buildings could instantly access comprehensive information about a specific piece of equipment across an entire global portfolio.

Whether or not this brave new world of M/E/P system management comes to be, it’s clear that the future of building systems will bring more power than ever to Building Teams and their clients.

About the authors
C.C. Sullivan is a communications consultant and author specializing in architecture and construction. Barbara Horwitz-Bennett is a writer and contributor to construction industry publications.

Take the AIA Exam  (one-time registration required)

This BD+C continuing education program qualifies for 1 AIA HSW learning unit.

Reed Business Information is a Registered Provider with the American Institute of Architects Continuing Education Systems. Credit earned on completion of this program will be reported to CES Records for AIA members. Certificates of Completion for non-AIA members are available on request.

       This program is registered with the AIA/CES for continuing professional education. As such, it does not include content that may be deemed or construed to be an approval or endorsement by the AIA of any material of construction or any method or manner of handling, using, distributing, or dealing in any material or product. Questions related to specific materials, methods, and services will be addressed at the conclusion of this presentation.

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