District Energy - 2007 Third Quarter

hot and noisy in the winter because of steam pipes are now quiet and cool. Steam lines to 16 buildings have been abandoned in place, and the remaining direct-buried steam lines will be abandoned as additional hot water loads are connected, further reducing maintenance costs and thermal losses. On the River Campus, for instance, only 56 percent of the steam leaving the plant over the past 12 months made it to individual building meters, resulting in $750,000 of energy wasted in the remaining steam distribution network.

Linking Hot and Cold

In addition to its district heating system, the university currently has a 22,000-ton steam turbine chiller plant and is constructing a new 4,000-ton electric satellite chiller plant. District cooling is provided to 42 buildings on the River and Medical Center campuses. Meeting continuously rising chilled-water demand has proved very challenging, particularly due to space constraints that make construction of new chiller capacity difficult. As an alternative, the university is currently evaluating liquid

desiccant dehumidification to minimize chilled-water growth and potentially decrease it substantially.

Liquid desiccants absorb humidity directly from outside air entering air-handling systems, avoiding the need to subcool outside air down to 55 F for humidity control and then reheating it for delivery to conditioned spaces. These systems are widely used in industrial applications, but their use in commercial and institutional settings has been limited by the large amount of low-temperature heat required to regenerate the desiccant.

Hot water district heating provides an excellent source for this service, and during the summer it appears possible to reduce the university’s existing chilled-water demand by more than 75 percent by using 165 F hot water as a regeneration heat source. This, in turn, significantly increases the amount of electricity cogenerated during the summer when market prices are generally higher.

Converting from steam to hot water has given the University of Rochester a new and efficient heating infrastructure, with minimal losses and maintenance expenses and an opportunity to address increasing

IDEA to turn

In 2009, IDEA will celebrate its centennial in Washington, D.C., at District Energy/CHP 2009, IDEA’s 100th Annual Conference & Trade Show. We’ll start commemorating the occasion in July 2008 as we begin featuring special content in District Energy magazine, offering special opportunities to members, and gearing up for the largest IDEA event ever.

We’d like your help!

Are you a longtime IDEA member? Does your company have a significant history with the association? Does your company count a past IDEA chair or president or Norman R. Taylor award winner among your own? If so, we’d like to hear from you!

Please share with us your personal or your company’s history with IDEA – special memories or celebrations. And we’d like your historic photos as well. Email them by Wed., Oct. 31, 2007, to idea@districtenergy.org. If you have questions, please contact Rob Thornton, president, (508) 366-9339, rob.idea@districtenergy.org.

demands for cooling. The extensive effort that went into planning and executing the project – in the quest to become ‘ever better’ – clearly paid off with the delivery of a quality installation that can best serve the needs of this growing campus.

Morris A. Pierce is energy manager and adjunct assistant professor of history at the University of Rochester in Rochester, N. Y. He has been with the University of Rochester since 1988 when he wrote his doctoral dissertation on the history of cogeneration and district heating while managing the university’s energy needs. He has written numerous articles on district energy and local heat supply planning, as well as the history of these subjects, and also teaches courses on the history of technology, environment and energy at the university. Pierce holds a bachelor of science from the U.S. Military Academy at West Point, a master’s degree from the University of Northern Colorado and a doctorate degree from the University of Rochester. His email address is mapi@mail.rochester.edu.