Incomplete testing and lack of design review

This police headquarters required an overhaul of its air handlers, building automation system, and lighting system.

12/27/2013


Due to the high energy use at this all-electric police building, exp U.S. Services was brought in to perform retro-commissioning and assess the problems and potential for energy savings. This large, 12-year-old, 5-story building houses the administrative offices for the police department, which was supposedly occupied 24/7. In reality, only a small portion of the building is occupied continuously. Two large air handling units (AHUs) serve the entire building through variable air volume (VAV) and fan-powered boxes (FPBs).

During the inspection, 20 of the 100 perimeter FPBs were found inoperative. These boxes are the only source of heat, and tenant comfort issues were common. Further investigation revealed some incorrect coding in the building automation system (BAS) programming was permanently holding these boxes in “unoccupied” mode. This error was corrected quickly, and all boxes began functioning properly. Although this was not directly an energy conservation item, it allowed the building operators to shut off the AHUs during winter nights because the FPBs would operate independently, and provide heat as needed. It appears that the BAS programming for these particular boxes was overlooked during the initial start-up of the HVAC systems.

The lighting in the building is adequate, and reasonably efficient fixtures were used, but at some point during design, the wall-mounted light switches were “value-engineered” out of the building. The theory was because the building would be occupied 24/7, the lights would never be off, and the switches were superfluous. In reality, only a small portion of the building is occupied continuously and the lights are left on 24/7, wasting large amounts of energy. Area-wide lighting controllers were installed, but subsequently taken out of service due to complaints of lights going off at the wrong times or other problems.

It seems that the proper design review by the CxA would have addressed this issue, and perhaps suggested an alternative design, such as occupancy sensor light switches that would control the local lighting and avoid the current energy waste. exp’s recommendation was to install an occupancy-sensing switch for each lighting circuit in the building. Although a costly option, the annual savings are 1,440,000 kWh and $102,000 for a payback of less than 1 year. 


Terrence Malloy is project manager for the energy solutions group at exp US Services Inc. He focuses on energy conservation, retro-commissioning, and renewable energy systems.



Consulting-Specifying Engineer's Product of the Year (POY) contest is the premier award for new products in the HVAC, fire, electrical, and...
Consulting-Specifying Engineer magazine is dedicated to encouraging and recognizing the most talented young individuals...
The MEP Giants program lists the top mechanical, electrical, plumbing, and fire protection engineering firms in the United States.
2017 MEP Giants; Mergers and acquisitions report; ASHRAE 62.1; LEED v4 updates and tips; Understanding overcurrent protection
Integrating electrical and HVAC for energy efficiency; Mixed-use buildings; ASHRAE 90.4; Wireless fire alarms assessment and challenges
Integrated building networks, NFPA 99, recover waste heat, chilled water systems, Internet of Things, BAS controls
Transformers; Electrical system design; Selecting and sizing transformers; Grounded and ungrounded system design, Paralleling generator systems
Commissioning electrical systems; Designing emergency and standby generator systems; VFDs in high-performance buildings
Tying a microgrid to the smart grid; Paralleling generator systems; Previewing NEC 2017 changes
As brand protection manager for Eaton’s Electrical Sector, Tom Grace oversees counterfeit awareness...
Amara Rozgus is chief editor and content manager of Consulting-Specifier Engineer magazine.
IEEE power industry experts bring their combined experience in the electrical power industry...
Michael Heinsdorf, P.E., LEED AP, CDT is an Engineering Specification Writer at ARCOM MasterSpec.
Automation Engineer; Wood Group
System Integrator; Cross Integrated Systems Group
Fire & Life Safety Engineer; Technip USA Inc.
This course focuses on climate analysis, appropriateness of cooling system selection, and combining cooling systems.
This course will help identify and reveal electrical hazards and identify the solutions to implementing and maintaining a safe work environment.
This course explains how maintaining power and communication systems through emergency power-generation systems is critical.
click me