Getting a Better Performing Building: Commissioning and Real Time Data Analysis

Commissioning of new construction is becoming increasingly accepted as a quality assurance tool to deliver performance, reliability, and efficiency in building systems. But what about existing building stock? Does successful commissioning of the construction process ensure design performance throughout the life of building systems? If you believe that commissioning is the key to acquiring a system that performs as intended, what about building systems that were never commissioned? Short of a substantial system failure, can we assume optimal performance? The answer is no. Performance verification requires a method of measurement. For those practitioners who have explored the commissioning of existing facilities, the consensus persists that existing buildings present energy saving opportunities upwards of 25%1, while reconciling mechanical system performance shortfalls, occupant comfort issues, and potential Indoor Air Quality (IAQ) issues. The key to identifying these lost savings is a measurement plan based on real time system operational data. Because of the dynamic nature and complexity of commercial building HVAC systems, they are the perfect target for periodic performance assessments, or recommissioning. Today's buildings are expected to supply designed conditioning and ventilation requirements as well as modulate to the loads and schedules of a variety of end use requirements throughout the building. Evaluating that the HVAC system is performing to load conditions is critical to the operating needs of the facility, and documenting that it meets the designed performance standards and the resulting energy use, and no more, ensures efficient system performance. The key to documenting system performance is the ability to access and analyze reliable system performance data. This paper will utilize EH&E's commissioning experience and methods to explore the relationship between HVAC system performance verification and good Measurement and Verification practice in both the commissioning of new construction projects as well as trouble shooting existing building problems