HVAC Optimization: High-Efficiency Chillers and Boilers
PJM performed a large HVAC optimization project that included the replacement of an existing absorption chiller with a high-efficiency centrifugal chiller and exchanging two large boilers with several smaller, more energy-efficient boilers.
The largest single user of natural gas in the client’s facility was the absorption chiller, which led to skyrocketing gas usage during summer months. The replacement centrifugal chiller uses more electricity than the existing absorption chiller, but the increase in electrical load was offset by a dramatic reduction in natural gas usage. Electricity use was further minimized by eliminating the primary chilled water pump and the addition of variable frequency drives (VFDs) for the condenser water pump and cooling tower fans. Primary and secondary piping systems were modified for the new chiller equipment, and the Building Automation System (BAS) was piped and programmed with new points and sequences to optimize efficiency.
Removal of the absorption chiller significantly decreased the facility’s steam load, so the facility’s two large 5,000 MBH boilers were replaced with six 1,000 MBH modular high-efficiency boilers. Boilers operate more efficiently at higher load, and the existing boilers would often be required to run at lower efficiency to satisfy a low heating load. The new modular units run only when needed at higher, more efficient rates, resulting in a substantial reduction in utility costs.
PJM worked closely with the design team and equipment vendors on the installation and startup of the various systems, as well as the commissioning effort, to ensure the new equipment and controls operated to the design intent.
PJM Mechanical Contractors, Inc. is a multi-faceted mechanical contractor providing construction and installation, service and maintenance, and design/build services in a comprehensive range of mechanical disciplines that include HVAC, plumbing, controls, refrigeration, custom metal fabrication, piping, fire protection, and backflow preventer testing. PJM primarily serves clients in pharmaceuticals, manufacturing, healthcare, institutional, and other various commercial and industrial sectors. pharmaceuticals, manufacturing, healthcare, institutional, and commercial sectors.