High-Performance Commercial Buildings
More and more, computer-based tools affect the design, construction, operation, and financing of commercial buildings. If properly deployed, an integrated set of such computer tools can help design, enhance, and maintain the operation of energy-efficient buildings. In addition to providing increased comfort and health and safety to the building's occupants, these tools should be interoperable throughout the building life cycle, contributing substantially to overall reduced energy demand and building performance.
The Present Situation
With national annual costs of more than $90 billion, commercial buildings account for 33% of electricity consumption. New buildings consume roughly 25% less electricity than those constructed 20 years ago, but this reduction in energy use is far below technical and economic potentials. EETD researchers Philip Haves, Mary Anne Piette, and Stephen Selkowitz posit that greater energy savings can be captured in several different ways. If only tune-ups and performance monitoring of existing buildings were performed, average energy use could be reduced by ~20%. If proven efficiency measures were applied when a building is retrofit (usually about every 15 years), an additional 50% reduction could be attained. Efficiency measures designed and constructed into new buildings could bring about an energy reduction of as much as 75%.
Studies show that significant savings are unlikely without the adoption of a systems perspective on building procurement and operation, leading to the consistent application of new tools and technologies across a building's life cycle. High-performance design solutions are not sufficient by themselves; effective commissioning and operating procedures are required to ensure that the design intent is realized.
EETD research identifies the critical R&D tasks needed to change commercial sector performance:
- High-performance components and systems;
- A set of interoperable tools that facilitate decision making in design, construction, commissioning, operation, and retrofit;
- An information infrastructure that facilitates information management.
Continuing development of low-energy technologies and systems is an important part of this R&D. However, the vision of efficient and productive commercial buildings cannot be achieved simply by deploying technology solutions. A comprehensive approach that accounts for how building decisions are made is required. A linked set of computer-based tools is needed to support decision-making at each phase of the building life-cycle.
New Tools and Integrated Building Technologies
Interoperable building tools must run the gamut from design to commissioning to operation to retrofit. Simulation-based tools are needed, not only for design, but also to verify energy performance as part of commissioning and during operation and to evaluate retrofit opportunities. Using the perspective developed by EETD, a series of new integrated technologies will be developed to reduce building energy use to a minimum. As an example, compare the following scenarios: At present, when a building is contracted, designers rarely perform energy simulations to investigate the potential savings of newer technologies. Building components are treated individually instead of as parts of an integrated system, and most individual systems are consequently oversized to guard against future complaints. When problems arise, individual systems are adjusted in isolation and no performance monitoring is carried out. Since utility bills are paid in single installments, there is little awareness of energy use.
Under an integrated approach, a client accepts a set of quantitative performance targets for the building based on monitored performance of other buildings. The design is then rendered with state-of-the-art simulation tools, incorporating cutting-edge technologies like low-energy fašades, efficient lighting, and daylightresponsive devices. Savings are realized from the downsizing of the chillers. Comprehensive commissioning is completed before hand-over and continuous monitoring of building performance leads to the correction of minor problems or equipment failures. As a result, building owners and operators have the information they require to keep their buildings running efficiently.
Some aspects of the latter scenario could be achieved relatively quickly. In others, factors ranging from the need for fieldtesting to the need to develop standards by consensus will limit the rate of progress. Present R&D has already contributed a number of computer-based tools that could enable some of the future scenario. However, development of tools is by itself insufficient; transformation of the market is required before these tools will be widely used. Demonstration projects, adoption of such strategies by government, partnerships and education, and innovative financing are needed to bring about acceptance of such an innovative concept.
For more information, contact:
- Philip Haves
- (510) 486-6512; fax (510) 486-4089
This research is supported by the California Institute for Energy Efficiency, the California Energy Commission, the U.S. Department of Energy, Office of Building Technologies, State and Community Programs, and the U.S. Environmental Protection Agency.