Optimizing the building operation is critical for improving a facility's thermal, energy, and economic performance while maintaining comfort. In this context, an energy audit is usually suggested, but it seldom is used as a diagnostic tool due to the complexity and the associated cost. The current investigation aims to use a multi-phase energy audit approach to diagnose the building's operation deficiency and proposes pragmatic retrofitting strategies. Several levels of effort were applied, including a walk-through audit, spot and short-term measurements, generation and calibration of building simulation model, energy and economic analysis. Various energy management opportunities (EMOs), such as adjusting the thermostat setpoint, modifying the operation schedule of the air conditioning system, replacing the conventional lights with more energy-efficient lights, and increasing the airtightness, were identified. These EMOs were further analyzed using a calibrated energy model using DesignBuilder software. The results indicated that the energy consumption and the energy cost could be reduced by more than 56% and 54%, respectively, while the comfort is maintained. The return on investment for these EMOs ranged between 0.2 and 9.1 years, with 1.8 years for the combined EMOs case. The outcome from this diagnostic energy audit was confirmed in the post-energy audit phase when one of the EMOs was implemented, and its impact was monitored, which indicated an actual energy saving of 34%. This study suggests that a diagnostic energy audit should be frequently practiced. The study also shows that whole-building simulation tools can be reliably used for evaluating expensive retrofitting strategies.

优化建筑运营对于提高设施的热能、能源和经济性能同时保持舒适度至关重要。在这种情况下，通常建议进行能源审计，但由于复杂性和相关成本，它很少用作诊断工具。目前的调查旨在使用多阶段能源审计方法来诊断建筑物的运行缺陷，并提出务实的改造策略。应用了多个级别的努力，包括走查审计、现场和短期测量、建筑模拟模型的生成和校准、能源和经济分析。各种能源管理机会 (EMO)，例如调整恒温器设定值、修改空调系统的运行计划、确定用更节能的灯代替传统灯，并增加气密性。使用 DesignBuilder 软件使用校准的能量模型对这些 EMO 进行了进一步分析。结果表明，在保持舒适性的同时，能耗和能源成本分别降低了56%和54%以上。这些 EMO 的投资回报介于 0.2 至 9.1 年之间，合并 EMO 案例的投资回报为 1.8 年。该诊断性能源审计的结果在实施一项 EMO 时的能源审计后阶段得到确认，并监测其影响，表明实际节能 34%。这项研究表明，应该经常进行诊断性能源审计。