Sense and sustainability
Careful planning and continued effort were key to commissioning HSBC’s North American headquarters.
The planning and effort put into the new 560,000-sq.-ft HSBC North American Headquarters to make it sustainable is a study in successful commissioning.
The building systems were designed with the purpose of reducing the carbon footprint of the building and minimizing energy costs. Lighting and HVAC occupancy sensors, an energy efficient envelope, rain-water reuse capabilities, and a reflective roof have made this possible.
A large structured cabling system reduces the amount of cabling and enables the building to accommodate further systems integration. Audio visual displays, security cameras, and building automation systems (BAS) all can be set-up on the same infrastructure.
Natural light is maximized throughout the building with an automatic window blind system that harvests daylight by reflecting it deeper into the space. A light-sensing luminary control system regulates the lighting panels depending on the amount of natural light available to provide the desired level of illumination.
Coupled with months of expanded commissioning, these sustainable and integrated strategies help the suburban Chicago office building in Mettawa, Ill., exceed ASHRAE standard 90.1-1999 by as much as 50%, helping the building earn a USGBC LEED NC gold rating. The site received a credit apiece in both fundamental and enhanced commissioning.
Early challenges and testing
Beginning with the project’s design phase in early 2006 and continuing throughout construction and post-occupancy this spring, expanded commissioning of the building helped link the owner’s project requirements to systems performance.
Back-up power increases sustainability
Reviewing test and balance reports generated by a third party, the commissioning team ran through test scripts for each system, opening valves and simulating each mode of operation, including device failures to eliminate malfunctions for first-time scenarios. Walking through each season, the team allowed the building to practice winter, spring, summer, and fall. With four to five commissioners over a period of six to eight weeks post-construction, each system was completely tested.
The facility’s integrated systems challenged commissioning as well. During one test of the HVAC equipment, temperatures were being maintained in air conditioning mode, yet the system was not performing as efficiently as designed. A quick look at the building information system (BIS) revealed a pressure imbalance; comparing cooling tons to the building’s electrical consumption didn’t match up. Site inspections and assistance from the general contractor led to the identification of a caulk and seal issue that repeated itself. The commissioning team now knew the irregularity was coming from an outside heat source; too much air was being introduced into the building.
Using the BIS as a tool, the imbalance was uncovered at the curtainwall: air was seeping in. The architect and contractor were brought in and the repair was made, with HVAC energy efficiency and consumption finally functioning as designed.
Without commissioning, HSBC building and design engineers wouldn’t have been able to make real-time measurements of the facility’s energy use and the problem may have gone undetected, resulting in a significant loss of energy over the 20- to 30-year life of the building. If left without a fix, this would have certainly caused the building to incur large costs due to unfiltered air and increased electricity use. However, using the BAS run times and the monthly and daily electric data from the local utility, the problem was identified and eliminated. This one find may have paid for the commissioning itself.
As the North American Headquarters for HSBC, the building also houses a corporate data center crucial to the company’s operations, which was to be occupied before to the rest of the building. This meant that mission critical systems needed to be intensely commissioned before building completion and prior to data center occupancy, only to be re-commissioned again with the rest of the facility after construction.
Personnel training and continued testing
Following design and testing, the commissioning team turned to training. Although engineer and operator education is often an afterthought, it is a vital part of maintaining an energy-efficient building. Attendees received more than 80 hours of equipment and system specific training in the classroom as well as at the BAS terminal and at the various equipment facilities themselves.
A challenge under the floor
Because of the sustainable and integrated properties of the building’s systems, site operators would need a thorough understanding of how to capitalize on operating efficiencies to save as much energy as possible going forward. For example, running two fans and two motors at a smaller load versus one on a higher load may be more efficient at times. The commissioning team trained building engineers on these issues and even brought in the air handler manufacturer to speak about appropriate compliance with design specifications.
Bringing the right teachers and students together in a sustainable environment can help establish a benchmark for future building efficiency and integration. The Environmental Systems Design team is currently still involved in seasonal commissioning at the facility throughout its first year in operation, maintaining the checks and balances at the company’s newest sustainable site.
Mike Kuppinger, PE, Senior Vice President, Mission Critical and Technology Group, Environmental Systems Design, Chicago, contributed to this article.