There are close to 700 courthouses in the U.S., but only one of them is the winner of the 2013 Better Buildings Federal Award Competition. The Wichita Courthouse achieved a 20% energy reduction within a 12-month time frame.
Built in 1932, the historical courthouse had already installed advanced metering and upgraded air handlers, boilers, chillers, and building controls in 2010. But performance monitoring by the GSA Region 6 Energy Team and courthouse staff determined that additional energy savings could be achieved through retuning building systems and implementing comprehensive energy management practices.
In 2012, a Targeted E4 (energy efficiency expert evaluation) was conducted to uncover no- and low-cost efficiency improvements. Recommended measures included static pressure and supply air temperature reset on the air-handling units, exhaust fan controls, optimal start for all AHUs, zero minimum outside air when AHUs operate during unoccupied periods, seasonal manual adjustments to chiller and pump valves, and lighting controls.
“Across GSA, we are working hard to make our buildings more energy efficient. In 2012, GSA reduced water usage in buildings by nearly 20% from 2007, ahead of its goal of 10%, which led to a cost avoidance of approximately $6.5 million. We are very proud of the work by the Wichita team. Their tremendous efforts are helping us exceed our sustainability goals and saving taxpayer dollars,” says Jason Klumb, GSA Heartland Regional Administrator.
Two project members discuss with BUILDINGS what they learned from the process.
What is a Targeted E4?
Linda Baschnagel, Heartland Region Energy Engineer – A Targeted E4 is a retuning process that targets improper or inefficient operations at no or low cost. Developed by the Pacific Northwest National Laboratory, it improves control strategies that the original design did not include. This systematic approach identifies operational problems by leveraging data from the existing BAS and correcting those problems.
While testing and balancing is important, it cannot improve operations or reduce energy usage if building equipment and systems have incorrect setpoints, poor schedules, and inappropriate control sequences. Proper commissioning is always a good practice because it ensures equipment and systems are operating as designed.
Another focus of the process is training building operations and maintenance staff. Use trend data to evaluate tenant hot/cold calls, diagnose operating conditions of equipment, and assess schedules of equipment vs. actual hours of operations.
Operators should also steer away from using overrides as a normal operating procedure and look instead at the system as a whole to make smart energy adjustments to the BAS. The O&M staff should also be trained on how to adjust or reverse any control system changes made during the retuning process in the event the changes do not work as expected.
Describe one of the challenges of this project and how it was overcome.
Brian Wohletz, Wichita U.S. Courthouse Building Manager – One of the biggest challenges we faced was finding a way to reduce energy usage while maintaining high tenant satisfaction. We overcame this by communicating to our tenants on a monthly basis any building management system scheduling changes that were part of the Targeted E4 retuning process. This is a practice we continue today to foster buy-in.
As the Targeted E4 team found opportunities, we implemented those measures while communicating with the affected tenants. We were fortunate to have good support from our tenants.
Our janitorial staff also helped in this effort. As the last eyes on the building each evening, they would ensure nothing was left on that was not needed.
Did you encounter any efficiency opportunities that surprised you?
Wohletz – We were surprised to find that our parking garage exhaust fans and air units were not scheduled to turn off after hours, instead running 24/7. With a few changes, we reduced the run times on two pieces of equipment by approximately 14 hours per day, achieving a 60% reduction in usage.
We also installed improved lighting controls, which are not integrated with the building automation system, in our parking garage. We replaced old analog timers with inexpensive digital timers. We are now able to precisely control the times the lights in the garage operate. The new timers have resulted in a 22% reduction in usage.
What energy management advice would you give to other building owners and managers?
Wohletz – Don’t get stuck looking for huge savings projects. The big opportunities are great, but remember that small opportunities can add up to large savings. Also use ideas from your building tenants. They may surprise you with something that is obvious to them but you may have overlooked.
Baschnagel – Utilize the building automation system to the greatest extent possible in your building. The capabilities of a sophisticated BAS are often underutilized in most buildings. The system is capable of scheduling and controlling the building systems much more efficiently than you can
A case in point is the integration of our chiller plant with the BAS, which allowed the chillers to run as needed and not 24/7 during the cooling season.
This integration allowed the implementation of plant scheduling, optimal start, and a new control algorithm to reset the chilled water supply temperatures for additional savings during non-peak months. The implementation of these measures accounted for 3% of the annual energy savings.