Computerized Commissioning Tools for Commercial Buildings

M.A. Piette, K. Heinemeier, F. Olken,* M. Sherman,Ý S. Selkowitz¦

*Information & Computing Sciences Division, LBNL.

ÝIndoor Environment Program, Energy & Environment Division, LBNL.

¦Building Technologies Program, Energy & Environment Division, LBNL.

Commissioning is a set of processes to ensure that building components and systems are installed and operated in an optimal fashion to meet or exceed design intent. Most buildings are not commissioned in a structured manner, which results in such significant problems as defeated energy-efficiency strategies, incomplete control sequences, and poor documentation on as-operated conditions.

Commissioning costs vary depending on the scope of the commissioning project and the complexity of the building. Our recent analysis of the benefits of commissioning has shown that it is often cost-effective in terms of energy savings alone. Efforts to reduce costs are needed to encourage more widespread use of commissioning processes and techniques.

Computer-based information technology is one approach to address the loss of information that occurs as a building moves from design to operations. We have developed a prototype chiller commissioning tool to assist in the development, customization, execution, and archiving of commissioning plans. This tool was developed as part of the Building Performance Assurance Project to develop Building Life-Cycle Information Systems (BLISS).

Part of the first year's efforts have focused on chiller commissioning, since chillers are the largest single energy-using component in buildings with central plants. As shown in the Figure, the first step in applying the software is to describe the characteristics of the chiller components (chiller size, type, design efficiency, flow rates, and operating temperatures). The software contains a general description of chiller commissioning activities and a module to record specific test plan methods, customized for a particular building (Step 2). Laptop computers can be used to track changes to test plans and collect data during plan execution (Step 3). Test results are recorded and outstanding issues and deficiences are tracked to ensure that the chiller is fully functional (Step 4). Long-term performance tracking methods are also defined for ongoing evaluation over the life of the building.

Second-year activities will cover four primary areas. First, to evaluate the software's usefulness and value in cutting commissioning costs and improving building performance, we will obtain feedback from commissioning agents. Second, we will expand the tool to be inter-operable with other computer-based building life-cycle information tools. These include such design tools as PowerDOE and the Building Design Advisor, and model-based performance tracking tools such as a calibrated (equation-based) SPARK model. Third, we will refine the tool based on user comments. Finally, we plan to increase the scope of the software to include additional cooling plant components, such as cooling towers. These improvements will culminate in a prototype cooling plant life-cycle information system.

Figure. The four steps of commissioning and the use of a computer-based chiller commissioning tool.

Reference

Piette MA, Nordman B, Greenberg S. Commissioning of Energy-Efficiency Measures: Costs and Benefits for 16 Buildings, prepared for the Bonneville Power Administration, Lawrence Berkeley National Laboratory Report No. LBL-36448, 1994.

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