Commissioning of A Large Office Building in Texas - A Case Study

Abstract

This case study involves commissioning of a large office building in the hot and humid climate of south Texas. The commissioning involved the installation of a VFD (Variable Frequency Drive) on a chilled water pump, improved EMCS (Energy Management Control System) programming and operation, and the installation of automatic chiller isolation valves, in addition to calibration and repair of building VAV (Variable Air Volume) boxes. In the case study building, four air-cooled chillers and two chilled water pumps were installed on the roof of a six-story, 141,514 ft^2 office building with very limited EMCS control. Some of the built-in chiller features such as staging and flow switch protection were unreliable due to age. Serious problems existed with humidity control, operation efficiency, and equipment protection in the building. By utilizing the existing EMCS as part of the Continuous Commissioning measures, several operational problems have been solved, and significant savings have been achieved. This paper discusses our procedures in identifying and solving moisture problems, the importance of cooling production and building load management, and the effectiveness and convenience of EMCS control.