The district heating and cooling loop that serves the core of Portland State University’s campus recently got an impressive efficiency upgrade in the form of two new boilers. Replacing boilers that were more than 55 years old, the two new units are estimated to save as much as $119,015 in annual energy costs and allow PSU to meet heating needs with only one boiler during non-winter months.
Powered by natural gas, the new boilers are located in the West Heating Plant near Peter Stott Center and boil water into steam that is used to heat many of PSU’s core academic buildings, including Neuberger, Smith, Millar Library, and the science buildings. The steam passes through coils to heat air that flows through ventilation systems in the buildings. When the steam cools, it turns to liquid that can be returned back into the boilers for reuse.
The new system also has a feature that preheats the water with exhaust heat from combustion before it enters the boilers, reducing the time and energy required to bring the water to a boil.
Noel Mingo, PSU’s utilities manager, estimates that the project will reduce PSU’s annual natural gas consumption by 10 percent. The initial project study also estimated a 67,848 kWh reduction in electricity use, and more than $3,000 in annual savings from reductions in water use and maintenance.
“The project sets the campus up for long-term, reliable, and efficient heating infrastructure,” says Quinn Soifer, a PSU engineer and lead on the project. Because they have a higher capacity to reach buildings farther from the heating plant, the new boilers allow for an expansion of the district heating and cooling loop into new buildings across campus.
Construction of the boiler upgrades began in April 2013 and was completed last month.
PSU’s newly established Green Revolving Fund will finance similar money-saving energy and water efficiency projects on campus in the coming years.