The persistence of energy savings due to the implementation of Existing-Building Commissioning (EBCx) is an important measure of the benefit of EBCx. This study analyzes the persistence of energy savings achieved from the implementation EBCx in nine buildings from 1997 to 2018. Each is served by a central utility plant (CUP) with metered chilled water (CHW) and heating hot water (HHW). EBCx was initially implemented in 1996/97. All buildings had follow-up ongoing commissioning or retrofit measures applied from 1997 to 2018. These and other building changes prevent accurate direct comparisons of 1997 EBCx savings with 2018 savings, but the overall 2018 savings are comparable to the 1997 savings due to the combination of ongoing commissioning measures and other energy efficiency measures implemented in the intervening years. This study examined the rate of savings degradation following each active intervention and the ability of exponential and linear decline expressions to model the savings degradation. Average degradation for HHW, CHW, and electricity savings was modeled equally well by exponential and linear decline expressions. HHW, CHW, and electricity showed predicted savings persistence of 59.3%, 80.6%, and 88.2%, respectively 10 years after the implementation of energy-saving projects if no follow-up were to be conducted.

由于实施现有建筑调试（EBCx）而持续节能是衡量 EBCx 效益的重要指标。本研究分析了从 1997 年到 2018 年在 9 座建筑物中实施 EBCx 所实现的节能持续性。每座建筑物都由中央公用设施 (CUP) 提供计量冷冻水 (CHW) 和加热热水 (HHW)。EBCx 最初于 1996/97 年实施。从 1997 年到 2018 年，所有建筑物都采取了后续的持续调试或改造措施。这些和其他建筑物的变化无法准确直接比较 1997 年 EBCx 节约与 2018 年节约，但由于结合了以下因素，2018 年的总体节约与 1997 年的节约相当在此期间实施的持续调试措施和其他能效措施。本研究检查了每次主动干预后储蓄下降的速度，以及指数和线性下降表达式对储蓄下降进行建模的能力。HHW、CHW 和节电的平均退化通过指数和线性下降表达式同样很好地建模。如果不进行后续跟踪，HHW、CHW 和电力在节能项目实施 10 年后预测的节电持续性分别为 59.3%、80.6% 和 88.2%。