University of Colorado Denver Anschutz Medical Center Research 1 Energy Efficiency Upgrades
Sean Convery, P.E., Cator, Ruma & Associates, Co.
Kenneth Neeper, University of Colorado Denver
The University of Colorado Denver (UCD) Anschutz Medical Campus (AMC) built a 600,000-square-foot research facility in 2003. Since its opening, the facility was unable to maintain safe hood operation while taking equipment offline for maintenance or failure. In 2009, Cator, Ruma & Associates was hired and tasked with conserving energy in the building without disrupting operations or safety, security, and comfort for the users. The first solution included rebalancing the system to achieve lower minimum VAV air change rates during occupied and unoccupied times, while still achieving safe airflow in laboratories. Minimum airflows were at eight to 10 air changes per hour (ACH) in the open laboratories and 32 ACH within the fume hood alcoves.
The first phase of the design involved lowering the air change rates to six ACH during occupied periods and to four ACH during unoccupied periods. Occupancy sensors in the new lighting control system allowed the unoccupied setback to be four ACH. Also, fan-coil units were installed in equipment rooms to allow the reduction of airflow to those spaces. The projected airflow savings is 90,000 cubic feet per minute (cfm) in the 300,000-square-foot South Tower. Since each exhaust fan is 50,000 cfm and each air-handler is 82,000 cfm, these could be taken offline while maintaining safety in the laboratories.
The UCD AMC Environmental Health and Safety Department performed two investigations in a pilot laboratory to test the phase one design prior to construction. The results showed the reduction in air changes was successful and maintained safe airflows. Phase two of the project includes the installation of a run-around heat recovery system, evaporative cooling, and condensate return systems for the process steam. The construction of phase two requires an exhaust fan and an air-handler to be out of commission for several days in order to install the heat recovery coils and evaporative cooling. This outage demanded the airflow reduction be achieved during phase one.
During construction, additional avenues were found to improve the reliability of the system during outages, such as the removal of sound attenuators that were not needed, thereby increasing the available static pressure in the system. Another method involved reprogramming the exhaust fan variable frequency drives (VFD) to achieve the full load amps rated for the motors. This allowed one fan to be disabled while the other fans maintained design airflows. The last method involved replacing the motors and the VFDs to achieve the maximum speed of the exhaust fans, thereby increasing the available static pressure in the system, which would improve reliability and account for the increased static pressure drop of the heat-recovery coils. In the end, the occupants encountered minimal impacts from a large energy efficiency upgrade project.
Biographies:
Sean Convery joined Cator, Ruma & Associates, Co., a mechanical/electrical engineering consulting firm of 90 people, in 1995, and is a senior associate in the mechanical department. Mr. Convery has a Bachelor of Science in mechanical engineering and is a professional engineer in Colorado. Mr. Convery has a broad array of experience in the design of mechanical systems, focusing on higher education campuses and research laboratories. Recent laboratory projects include the Colorado State University Research Innovation Center (LEED® Gold pending), Front Range Community College Sunlight Peak Science Building (LEED Gold pending), University of Colorado Boulder Systems Biotechnology Building (LEED Gold pending), and UCD Research Complex energy-efficiency upgrades. Mr. Convery was a presenter at the Labs21 2010 Annual Conference and has received engineering excellence awards from the American Council of Engineering Companies in Colorado for his designs at complex biosafety level-3 campuses.
Kenneth Neeper joined UCD in 1997 to supplement staff in the development of the former Army base into a medical campus. Mr. Neeper has a Bachelor of Science in civil engineering and a broad range of experience in operations, programming, design, and construction on large campuses, with a specialization in medical facilities. In his current role as manager of infrastructure, Mr. Neeper has overseen the development of infrastructure, the central utility plant, and parking for 6,000,000 square feet of research, hospital, and educational space. As a project manager, Mr. Neeper also provides construction management services for the renovation of campus research facilities.