A perfect storm is heading for the building industry. Energy prices continue to rise due to worldwide demand that increases both the cost of construction and building operation for owners and developers. The public is becoming increasingly concerned about the environment and global warming and demanding that both the pri-vate and public sectors act to reduce greenhouse gases. In addition, the United States produces only a fraction of the energy it uses on a daily basis, obtaining much of its needed energy from foreign suppliers. This energy deficit is raising concerns about national security and adversely impacting the U.S. economy.
Each of these issues has been around for decades, but only recently have all three converged and been seen as interrelated. For the first time, business leaders, environmental activists, government officials and the general public are aligned and focused on finding an integrated solution to energy, environmental and economic issues. This perfect storm will provide a great deal of opportunity for elec-trical contractors prepared to aid in recovery efforts.
Building energy use
According to the U.S. Department of Energy’s Energy Information Agency (EIA), commercial and residential buildings consume about 40 percent of the energy used in the United States, and annual energy usage is expected to increase in coming decades despite efforts to conserve.
In comparison, the U.S. industrial and transportation sectors each only accounted for about 30 percent of the U.S. annual energy us-age. Similarly, according to the EIA, commercial and residential buildings also account for about 40 percent of the carbon dioxide (CO2) emissions, which also is greater than either the industrial or transportation sectors. Therefore, there is a lot to be gained by reducing building energy use in the country or by supplanting traditional fossil-fueled electricity production with greener technologies, such as photovoltaic (PV) and wind generation.
The need to rein in building energy use is driving many federal, state and local governments to adopt increasingly stringent energy codes. Building owners more often are challenging their design and construction teams to produce high-performance buildings that exceed the minimum energy requirements.
A number of professional, industry and trade organizations in the building industry are promoting sustainable design and construc-tion practices including the reduction of fossil fuels used to construct and operate buildings with the goal of achieving “carbon neutral” buildings in the coming decades. Since electrical energy use in buildings often can range from 65 to 100 percent of a building’s total en-ergy supply, depending on geographic location and space heating, the electrical contractor will be in the eye of this perfect storm as it develops.
Many in the construction industry envision the future to be zero-energy buildings (ZEBs). A ZEB is a building that is completely energy self-sufficient, producing all the energy it needs internally. It does not need to be connected to the local utility’s distribution system. Currently, PV is seen as the most promising distributed generation technology for ZEBs because PV uses sunlight to produce electricity, conversion efficiencies are increasing, manufacturing costs are decreasing and utility energy prices are increasing. These trends are mak-ing PV both green and economical. Unfortunately, PV only produces energy when the sun is shining, and a ZEB must be able to store electric energy for use at night and on cloudy days when the PV array is not producing. Reliable low-cost energy storage is an obstacle that will need to be overcome before ZEBs become a viable alternative in locations where electric utility service is readily available. However, some recent strides have been made.
Net zero-energy buildings (net ZEBs) will probably be implemented first in states where a net metering provision allows building owners to provide energy to the utility when their PV array is producing more than needed and pull energy from the utility when the building load exceeds the capability of the PV array. The utility only bills the owner for the difference between the amount of electricity used by the building and what was produced and delivered by the PV array to the utility distribution system. With net ZEBs, the amount of energy produced annually by the PV array meets or exceeds the annual building energy need, even though there is an exchange based on when the electric energy is produced by the PV array and needed by the building. The utility distribution system in effect serves as the en-ergy storage device for a net ZEB.
Building system integration
The kind of building performance breakthroughs needed to substantially reduce building energy use and associated greenhouse gases in the near term, and ultimately achieve ZEBs in the long term, requires building system integration. The traditional view of a build-ing as a collection of loosely related systems that are individually optimized during the design and construction process typically results in a building that performs less optimally as a whole. In contrast, high-performance buildings require that individual build-ing systems, such as the building envelope, power generation and distribution, artificial and natural lighting, heating, ventilating, air conditioning and other building functions be treated as subsystems and that the building be the system to be optimized.
Integration and interoperability are popular terms in today’s building industry. These reflect the reality that, in a modern building, the operation of each system affects all other systems.
For instance, about 30 percent of the energy used by commercial buildings is used for artificial lighting. Increasing the amount of glass on the building’s exterior will increase the amount of natural light entering perimeter spaces and should reduce the need for artificial lighting. However, increasing the amount of glass and the amount of light entering the space will impact the HVAC system load, which needs to be taken into account.
Similarly, in order to ensure adequate light levels and quality, a lighting control system needs to be installed that will adjust the arti-ficial light levels based on the natural light entering the space. Furthermore, occupancy sensors placed in a space to reduce energy use by turning off lights when spaces are unoccupied also can be used to reduce HVAC energy by turning down variable-air-volume boxes if the air distribution system has been zoned to do so.
The goal of building system integration is to optimize the building’s overall operation in order to provide a healthier and more pro-ductive environment for occupants as well as to increase the efficiency of building operations. The realization of this goal requires the integration of key building systems, using a building control system.
The electrical contractor can be involved in the installation of individual control system components, such as the raceway system, layout and installation of proprietary control systems, or the design and installation of open-architecture control systems. Electrical contractors often install control systems that deal with a particular building function, such as lighting, data and communications, fire alarm, or security. These individual systems usually are integrated together with the HVAC system controls and other building systems by the building management system. However, with open architectural control systems, the EC can become the system integrator if it has the ability to design, install and program the control system. Building system integration represents an important future market for electrical contractors.
CSI Division 25/Integrated Automation
The growing importance of building system integration is illustrated by the inclusion of Division 25 in the 2004 edition of the Con-struction Specifications Institute’s (CSI) Master-Format. CSI MasterFormat serves as the basis for most specifications in the United States, and Division 25 specifies the integrated automation (IA) system that ties together all of the subsystems represented by Master-Format Facilities Subgroup along with Division 11/Equipment and Division 14/Conveying Systems. The Facilities Subgroup includes Division 21/Fire Suppression, Division 22/Plumbing, Division 23/HVAC, Division 26/Electrical, Division 27/Communications, and Division 28/Electronic Safety & Security. Division 11 covers equipment that serve a unique function in a building, such as food service, laboratory or athletic equipment. Conveying systems, such as elevators and escalators, are covered in Division 14.
The figure at left illustrates the relationship between CSI Division 25 and all of these other divisions. From the figure, it can be seen that the function of the IA system is to bring all of these individual building systems together in order to optimize building perform-ance. All the hardware and software needed to implement an IA system are specified in CSI Division 25. This includes conductors and raceways; network equipment, such as servers and hubs; instrumentation and terminal devices, which interface directly with building equipment or through system-specific devices specified elsewhere; gateways, which establish a communications link between the IA system and other stand-alone building systems; and control sequences that describe how the IA system is to operate.
The EC’s role
High-performance buildings require that buildings be designed, constructed and operated as a single integrated system rather than a collection of loosely related, independent systems that are individually optimized as done in the past. The design and installation of building control systems is the key to reduced energy consumption and operating costs over the life of the building. Building owners need help designing, installing and maintaining these building control systems. The electrical contractor should be aware of this con-verging storm and begin to prepare to move in and tackle the challenges.
This article is the result of a research project investigating the emerging integrated building systems market that was sponsored by ELECTRI International Inc. The author would like to thank EI for its support.
GLAVINICH is an associate professor in the Department of Civil, Environmental and Architectural Engineering at the University of Kansas. He can be reached at 785.864.3435 or firstname.lastname@example.org.