UI to use efficient "chiller-heaters" to heat new residence hall
As the University of Iowa moves toward its goal of being 40 percent renewable energy efficient in 2020, UI energy engineers are working to implement a more efficient energy system in the newest dorm.
The system, which involves “chiller-heaters,” recovers excess heat from buildings and machines that are cooled by air-conditioning all year round.
The process involves sending chilled water at 42 degrees to buildings that need to be cooled. The water comes back out of the building at approximately 55 degrees and goes back to the chilled-water plant, where it is prepared to heat other buildings.
“Some buildings need to be cooled during the entire year, due to computers and other machines that have to stay cool in order to be functional,” said Ben Fish, the UI Facilities Management assistant director of utilities and energy. “It seems odd, but you can use 55-degree water to heat the building.
The system uses the chemistry of coolant, and the coolant takes the heat out of the water.”
Fish said the new indoor football practice facility uses a similar heating system, but unlike the new dormitory, the practice facility will not be cooled in the summer.
“The new dorm will be the first building occupied by a large number of people that will use this system,” Fish said.
Costs for the project were not readily available Sunday evening.
Liz Christiansen, the director of the UI Office of Sustainability, said the process is in accordance with the UI’s 2020 Sustainability Vision.
The project — which involves federal, state, and local government — along with businesses in the Iowa City area, aims to make the UI more efficient in energy by installing processes such as this. The project engulfs a 50-mile radius, in which officials look for other opportunities for securing renewable energy.
“This process is groundbreaking,” Christiansen said. “Our energy engineers are constantly looking for more opportunities to make the UI more efficient.”
Christiansen said the UI uses between 9 and 13 percent renewable energy, which she attributed to the Quaker biomass project.
The project, which has been in use for 10 years, harnesses alternative energy by burning oat hulls, which are purchased from the Quaker Oats facility in Cedar Rapids.
Fish acknowledged that confusion has come about regarding the process of heat recovery and geothermal energy.
“Sometimes, people associate geothermal with green energy,” Fish said. “Unfortunately, that’s not always the case. However, becoming more efficient is a very good thing.”
The UI will also implement a full-capacity steam backup system, which will heat the dorm if the “chiller-heaters” fail.
“It’s not that we don’t trust the design,” Fish said. “We feel more comfortable with the system if we have a backup. Reliability is a very big deal with us.”
Zach Carter, president of the UI Sierra Student Coalition, said the system is good from the standpoint of efficiency.
“It makes sense the capture the residual heat, since we would otherwise waste it,” Carter said.
Carter also said it’d be a good idea to change the source of our fuel entirely, and moved towards geothermal energy.
“Any energy efficiency measures are good ones,” he said.
Fish noted that although the heat recovery process will help the UI become more efficient, it does have limitations.
“We can’t use it building after building,” he said. “We’d simply run out of heat to be transferred around.”
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