Urban Skyscraper

Business Activity: Multi-Tenant Offices
Location: Chicago, Illinois
Project: Commissioning (Monitoring-Based Commissioning)

Sieben Energy Associates was selected to pilot a monitoring-based commissioning program at a multi-tenant office building in downtown Chicago.  The 1.3 million square foot skyscraper is one of the tallest buildings in the United States. Partnering with a nonprofit program administrator and utility sponsor, SEA’s project endeavored to reduce the building’s energy consumption by 1 million kWh annually. The year-long program was one of the first of its kind, and its’ successful practices will inform future projects that use innovative engineering to improve energy efficiency.

Monitoring-based commissioning merges traditional energy auditing with cutting-edge modern technology and telecommunications. The SEA energy engineering team collects and analyzes information remotely employing a custom-built database to evaluate data from the building’s heating and cooling equipment. Interpreting the data, SEA was able to recommend energy efficiency improvements, track their implementation, and adjust as necessary over the course of the project.

One significant source of savings during the project was meticulously monitoring and altering of the building’s air handling units to use their power efficiently, while maintaining a comfortable environment for the tenants. Eliminating “morning warm-up” on days that fell within a determined optimal temperature bracket saved roughly 250,000 kWh over the course of a year. Achieving that success was directly related to the long-term, continuous study of the building’s energy usage patterns. Similar savings opportunities were found by reducing static pressure in the air handling units during the winter, and adjusting the input of outside air for cooling. Successfully, reducing static pressure required rigorously determining optimal pressure and automating a sensor system to relay the reset. Adjustments in the AHU’s static pressure saved the building over 350,000 kWh a year. A combination of programs which regulate the use of outside air saved over 300,000 kWh a year.

The project goal was to save 1 million kWh over the course of the year; SEA’s monitoring-based commissioning program exceeded that goal saving the building 1.3 million kWh during the pilot program year. Continued use of the monitoring-based commissioning program program will reduce the building’s energy costs by $100,000 a year.