Addressing Fluctuations in Campus Heating Requirements

The University of Arizona operates and maintains a campus steam production and distribution system serving over 130 buildings, with a generating capacity of over 320,000 lb/hr of saturated 100 psig steam. The campus is comprised of many building types and uses including a Level I trauma hospital, research laboratories, classroom/office buildings, large auditorium spaces, student housing, and NCAA Division I Sports complexes. Campus heating loads can fluctuate significantly over the course of a year, month, and even day. Steam was produced via a combination of large natural gas D-Style water tube boilers and two heat recovery steam generators installed in unison with the heat recovered from the electric producing high pressure gas turbines. The University had difficulty maintaining a production profile that paralleled the moving target of campus load. The University, with the assistance of GLHN Architects and Engineers, explored options to help synchronize the demand and production profiles. The selected solution provides the ability to quickly modulate production capability through the use of efficient modular type boilers while the much larger D-Style boilers maintain the campus base loads. For more information on this topic, please contact Bill Koller at GLHN, (520) 881-4546 or