The campus is located at the southwest corner of 6th Avenue and Kipling Street. The facility consists of multiple laboratory spaces, data centers, research offices, and general administration areas utilized by 28 federal agencies. The campus buildings are served by central heating plants and central cooling plants. The central heating and cooling plants located in Building 41 were part of the project scope. These plants consisted of two 8,165 MBH steam boilers that provided heat to heat exchangers that provided heating water to the building’s air handling unit and terminal unit heating. Two 500-ton chillers and one 1,250-ton chiller rejects heat to a 3 cell evaporative cooling tower and provide chilled water to four of the campus buildings, distributed by a primary/secondary variable flow pumping system. The cooling plant also provides chilled water economization by way of flat plate heat exchangers. Both plants are controlled by a Siemens-based building automation system (BAS), which also controls air systems and lighting throughout several buildings.
The retro-commissioning of these eight buildings at the Denver Federal Center, including the heating and cooling plants, was funded by the General Services Administration (GSA), and undertaken in an effort to improve operations and energy efficiency of the various building mechanical and electrical systems. Operation of the energy consuming systems of the building was carefully reviewed and a large number of improvement measures were developed and implemented. A variety of retro-commissioning tasks were performed to provide a thorough investigation of the buildings. Some of these tasks are as follows:
• Perform a complete building load calculation for each of the eight buildings.
• Implement a complete air-side TAB assessment of all major air handling units.
• Investigate building pressurization issues related to indoor air quality and energy efficiency.
• Review and address occupant comfort issues.
• Review all HVAC equipment operation and provide a list of maintenance and repair items.
• Inspection of the building envelope to determine the envelope’s condition and potential deficiencies that may affect the building performance.