Song Deng

Is Commissioning Once Enough

ABSTRACT Over the last decade, the Energy Systems Laboratory has developed a commissioning process called Continuous Commissioning®. This process is used to resolve operating problems, improve comfort, optimize energy use, and sometimes to recommend retrofits. The process has produced average energy savings of about 20 percent without significant capital investment in over 150 large buildings in which it has been implemented. Payback has virtually always been under 3 years, with two years or less in most buildings. This article describes the process and presents a case study that explicitly shows the value of follow-up consumption tracking and commissioning. Examination of 20 building-years of heating and cooling consumption data from commissioned buildings found an overall increase in heating and cooling of 12.1 percent over two years. Almost 75 percent of this increase was caused by significant component failures and/or control changes that did not compromise comfort, but caused large changes in consump...

OPERATING STRATEGIES FOR CAMPUS COGENERATION SYSTEM IN A TURBULENT UTILITY MARKET

The future is unpredictable, natural gas prices are fluctuating wildly, and electricity rates are increasing sharply as a result of higher fuel prices. In unstable utility market environments like we are seeing today and that we expect in the near future, operating a large university cogeneration system presents opportunities as well as challenges. Will the existing generate-as-much-as-we-can and buy-the-rest operation scenario continue to be the best, or does the operation need to be optimized? If operational changes are recommended, what is the optimum scenario? How sensitive is the optimum scenario to natural gas prices and electricity purchase rates? The Texas AM generate as much electricity as you can and buy the rest; operate in a pure Combined Heat and Power (CHP) mode and buy the rest; and operate the CHP units during summer months only and buy the rest. The above scenarios are also evaluated with an overhauled and more economical gas turbine/generator set. The fact that Texas A&Ms cogen system can produce up to 65% of its own electricity, has both electric-driven and steamdriven chillers, and can purchase its additional electricity on the wholesale market presents additional opportunities and operating strategies, which will be discussed in the paper.

Continuous Commissioning® of a commercial building in Austin, Texas

ABSTRACT Continuous Commissioning®* technology has been proven to be highly cost-effective in reducing building energy consumption. This article illustrates a successful continuous commissioning project that has been recently completed in a commercial building in Austin, Texas. Even though the buildings HVAC systems were well maintained and their operations had been tuned by an experienced facility management team, the CC® project was still able to achieve an annual cost saving of

Persistence of Savings Obtained from Continuous Commissioning SM

287,400 (14 percent of the total utility costs, or 60¢ per square foot per year) by further optimizing the operations of various HVAC components, the chilled water and hot water loop systems, and identifying malfunctioning control devices. The simple payback of the CC project was estimated to be less than 7 months.