Mark Hancock, P.E. — Feb 2014
Pantages Theatre has high energy use despite a fairly small conditioned area of 25,000 square feet and low occupancy. The NRG Energy Center MInneapolis, which provides steam and chilled water to the theater, wanted to help reduce their customers’ energy consumption and suggested Theatre management consider a CEE Existing Building Commissioning study.
CEE conducted a comprehensive study at the theater in 2013, collecting continuous trend data on all of the mechanical equipment in the building for seven months. They analyzed trend data to identify and quantify energy saving improvements. The theatre has variable operating conditions, so CEE staff shadowed the building operator on a show night to see equipment operation in response to changes in occupancy and space conditions, and to understand show day dynamics to ensure realistic energy saving recommendations.
One area of focus was the interaction between the theater and an adjoining restaurant containing three kitchens. The restaurant was drawing air from Pantages because the kitchen hoods were left on continuously, drawing in so much air from the theater that is became negatively pressurized. CEE conducted an air leakage investigation and determined that sealing the air leakage pathways would help prevent the depressurization.
Trend data analysis revealed that the largest air handler, which served the auditorium, brought in more outside air than needed for ventilation, especially since the space was usually unoccupied. By creating a Pre-Show more during which the outside air dampers would remain closed and the fan speed would be limited to a set percentage, the pace would gradually reach the occupied temperature set point, minimizing spikes in steam or chilled water demand.
Implementing all of the recommended improvements would cost $7,400. Pantages Theatre would save $5,230 annually, leading to a payback of 1.4 years. .