When it comes to high-performance operations, one of the first places to start is with building information. This information can help drive better operations and better building performance.
As demonstrated in a recent energy management study conducted by the NRDC at three buildings owned and operated by The Tower Companies — a real estate development and management firm in Washington, D.C. — those smarter approaches at the core of the BOMI International High-Performance Program (see “BOMI’s High-Performance Program” on this page.) can produce tangible, sustainable results. The study showed how a better-informed building operations team could work together to provide actionable recommendations that optimize energy use.
The initiative, which involved three large, multitenant commercial buildings Tower owns and operates in Washington, D.C., focused on operational improvements — measures that do not require construction, disruption to occupied buildings, or substantial capital investment. The goal was to discover what could be gained by a closer examination of the building automation systems in real time. What resulted, as detailed in a recent case study released by NRDC, was a model for building owners, tenants, efficiency programs, and others to conduct their own energy management initiative.
Two outside firms were brought in to help analyze the buildings’ automated systems, pinpoint problems, and recommend fixes and improvements. Note Phillip Henderson and Meg Waltner, authors of the study, “The three buildings in this case study were high-performing buildings before the energy management initiative began — the buildings had high Energy Star scores and were good facilities.”
In fact, 1707 L Street had an Energy Star score of 71, 1828 L Street had a score of 78, and 1909 K Street had a score of 86 in September 2011. Yet, at the end of the study period, the scores for all three buildings had improved substantially — to 91, 87, and 88, respectively. The fact that these already high-performing buildings realized substantial savings during the initial 12-month study period suggests that even greater gains can be achieved in typical buildings. In fact the buildings have continued maintain and even improve performance as Tower approaches the end of the second year of this initiative.
What the building operations team realized through the analysis and improvements was significant electricity savings: 23 percent in 1707 L Street, 7 percent in 1828 L Street, and 17 percent in 1909 K Street. Electricity use was reduced by 13 percent across all three buildings during the study period. The reduction in electricity expenses averaged $72,901 per building ($218,703 across all three buildings) in 2012.
A key element of the initiative was detecting and correcting operational stray. When a building is well managed, there’s an assumption that stray is not happening. But, as the study revealed, in even the best-managed buildings, building systems stray from optimal; Tower’s initiative showed how better information can minimize stray and reveal it quickly. For example, the review of electricity use in 1909 K Street uncovered an unusual pattern. Both of the building’s chillers were cycling on for a few minutes at a time, then shutting off. The building engineer was alerted and, working together, the team found and corrected faulty variable air volume controls that were signaling the chiller to turn on even though the building management system called for the chiller to remain off. Write Henderson and Waltner, “While this problem might have been discovered eventually without the comprehensive energy-use analysis, it could have continued undetected for months. This delay would have resulted in wasted energy, wear and tear on the building equipment, and possible disruption to tenants when equipment failed.”
At the same time, recommendations were made to implement best practices, such as regularly auditing controls to confirm that the temperature deadband is set at 4 degrees. This means the HVAC system would cool the building to, say, 72 degrees, then remain off until the temperature rose to 76 degrees. A larger deadband allows the HVAC system to remain off while the building is in the “comfort zone,” resulting in energy savings and reduced wear and tear on equipment.
Another important element of Tower’s initiative was creating a detailed alarm service for building systems. Procedures were established to remotely monitor certain system settings, such as chilled water temperature, and to send messages to the building engineer if system conditions were outside defined parameters.
The total cost of the project for the three buildings was $144,320, and the electricity use savings was $218,703. And because the costs in 2012 included the installation of the new systems and procedures, the annual operating cost to achieve those same electricity savings going forward will be significantly lower: $65,520. The assumption that these improvements are expensive to implement was refuted by the study’s conclusion that they can be a profitable venture for the owner or operator.
Article By: David Borchardt