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Functional Testing Guide Aids Buildings Teams

Highrise office buildings with a sun reflection.

Commissioning complex commercial buildings—understanding the many test procedures involved and the energy use that they assess—requires an in-depth understanding of building heating, ventilation, and air-conditioning (HVAC) systems in particular. To communicate this understanding to the building commissioning industry, scientists and researchers in the Environmental Energy Technologies Division (EETD) have developed the Functional Testing Guide and Model Functional Test for Air-Handling Systems (FT Guide). The guide presents a series of model functional tests that describe many common air-handling system configurations. It was developed as part of a large building-commissioning research project currently under way (see EETD News, Vol. 2, No. 4, Summer 2001).

Commissioning is a valuable method of ensuring building performance; reducing energy use; and improving indoor air quality, occupant comfort, and productivity. As the commissioning industry continues to expand, so does the need for tools to deliver quality services at reduced costs. One way to reduce costs is to produce project-specific test protocols from standardized templates.

To meet this need, researchers Mary Ann Piette and Norman Bourassa, among others, worked with Portland Energy Conservation Inc. to compile a library of standardized functional test procedures, with funding from the California Energy Commission's Public Interest Energy Research Program (PIER) and the U.S. Department of Energy (DOE). Pacific Gas and Electric Company (PG&E) recently completed this library, which is called the Commissioning Test Protocol Library (CTPL). The team then used the library to produce the FT Guide, which reviews the basic concept of functional testing, including references to other tests, along with information such as why a test is important, when it should be performed, and what its costs and benefits are. The guide will also help commissioners understand the possible outcomes of a test sequence.

This example illustrates how economizers operate. The amount of outdoor air needed to maintain a supply temperature set point depends on the outdoor air temperature (Circles 1 and 2). Typical office environments do not require preheating until it is cold outside (Circle 3). Most economizers in California buildings do not perform at optimal levels; understanding their operation can lead to significant energy savings. The FT Guide explains these and other issues in depth.

Figure 1. The FT Guide provides details on air-handler component design and operation. This example illustrates how economizers operate. The amount of outdoor air needed to maintain a supply temperature set point depends on the outdoor air temperature (Circles 1 and 2). Typical office environments do not require preheating until it is cold outside (Circle 3). Most economizers in California buildings do not perform at optimal levels; understanding their operation can lead to significant energy savings. The FT Guide explains these and other issues in depth.

The FT Guide covers air-handling systems only and emphasizes energy efficiency because air-handling equipment can often consume 30 to 50 percent of a building's energy. The majority of HVAC systems have some form of air-handling equipment and distribution system. Control requirements are also discussed in a section of the guide that addresses integrated operation of the control system and the components of the air-handling unit. An example is shown in Figure 1.

Designed to assist users in choosing the appropriate levels of testing, the FT Guide is oriented toward commissioning of new construction but can be useful for recommissioning as well. Together with the CTPL, the FT Guide is a step toward standardization and quality control, which continue to be significant issues in the commissioning industry.

— Ted Gartner

For more information, contact:

  • Mary Ann Piette
  • (510) 486-6286; fax (510) 486-4089

Download the Functional Testing Guide.

Funding for this research was provided by U.S. DOE, and the California Energy Commission.

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