Condition Assessment, Re-Commissioning, and Measurement & Verification: A Multi-Year Study of Army Buildings

Over the past decade the HVAC systems in many Army buildings have not received adequate maintenance because of budget limitations and maintenance staff reductions. As a result, the HVAC control systems in buildings that are ten or more years old are typically in poor operating condition. In the late 1990's, the Public Works Business Center at Fort Bragg, North Carolina entered into a number of performance contracts to re-commission the HVAC systems, especially the control systems, in a number of buildings. Since the control systems in many buildings were inoperable, occupants complained that their rooms were too cold in summer, too hot in winter. The HVAC systems also operated 24 hours per day even though they were originally designed to shutdown during unoccupied periods. This paper presents the results of a five year study of five buildings. The purpose of the study was to assess the performance of the HVAC/control systems immediately after the performance contractor had completed the work, and to monitor their operation for a period of one year following re-commissioning. Data was collected to: (1) confirm that the HVAC systems were operating in accordance with the performance contractor's specifications; (2) monitor room temperature and humidity; and (3) estimate the energy savings that resulted from re-commissioning. Sensors and micro-dataloggers were used extensively throughout the project to monitor the buildings. A total of 12 undergraduate and graduate students from the Architectural Engineering Department of North Carolina A&T State University were involved in the project. The secondary objective of the project was to provide Architectural Engineering students with real world measurement and verification field experience.