Overview

Swarthmore College (Swarthmore) needed to understand their aging campus utility infrastructure to develop a cost-effective and forward-thinking plan to prioritize replacing or upgrading their existing heating and cooling systems, in order to improve reliability, increase efficiency, and ensure proper capacity while their campus continued to expand. We provided assessment and recommendations for Swarthmore to serve as a utility master plan for their heating and cooling utilities.

Solution Details

Swarthmore provides campus heating and domestic hot water via their central steam plant, which operates year-round. From a maintenance perspective, the plant and steam distribution piping were in overall good condition, only requiring replacement of the deaerator and upgrading controls to efficiently control and monitor the plant’s output. During the summer months, besides providing hot water, the steam from the plant was used to operate an existing absorption chiller to cool the campus.

The central chiller plant provided campus cooling for 15 buildings. The main source of cooling was an existing absorption chiller that was in need of $300,000 in maintenance and repairs. Swarthmore also had an existing gas-fired chiller that was in good condition.

Swarthmore’s heating and cooling utility systems are sized correctly to meet the current growth projections of the campus. With some cooling equipment approaching the end of its operating life, an opportunity existed to achieve significant energy savings that would impact both heating and cooling, by changing operations at Swarthmore.

The aging absorption chiller was recommended to be replaced with a new electric chiller with thermal ice storage. A 600-ton chiller with 5,000 ton-hrs of ice would allow off-peak cooling operation with full storage. This unit would supply the base load of cooling for the campus and the existing gas-fired chiller could be utilized during peak demand. This change in concert with decentralized building domestic hot water units would allow for summer shutdown of the central heat plant, eliminating 3,000 lb/hr of distribution losses during shutdown, and providing a substantial maintenance period annually for the central heat plant and distribution piping.

The total project costs for Swarthmore’s utility master plan provided itself with a simple payback period of only 10 years, after the energy savings were incorporated. Swarthmore was able to make an informed decision, rather than just replacement-in-kind, in favor of the recommended heating and cooling changes and upgrades, providing energy savings and lessening environmental impacts of their campus utilities.