Cornell University is undergoing a major transition in its heating infrastructure, converting the current steam heating system to a more efficient hot water network as a part of its 2035 goal of carbon neutrality.
The conversion to hot water heating is one of six actions by the University to reach net zero emissions by 2035. Other actions include implementing Earth source heat, improving the efficiency of campus buildings, solar and hydropower projects and developing carbon sinks — such as unmowed grass.
The shift to hot water, which is already underway, aims to increase efficiency, reduce carbon emissions and enhance safety for maintenance staff.
Cornell’s current system consists of 13.4 miles of steam line that can reach up to 450 degrees, delivering heat to campus buildings. However, according to Cole Tucker, director of utilities distribution & energy management, this system experiences a 25 percent distribution loss — meaning that a quarter of the head produced is lost in the process of distributing it throughout campus. By switching to hot water, Cornell aims to significantly improve its energy efficiency.
“Once the full system is converted to hot water, we expect those losses to reduce to 5 percent,” Tucker said.
The new system will operate at a much lower temperature by utilizing hot water in place of steam, reducing thermal losses and improving insulation. According to Tucker, this transition is essential for integrating electric-based heating solutions, such as heat pumps and earth-source heat, which require a water-based distribution system.
As Cornell hopes to integrate electric-based heating production equipment by 2035, Tucker claims that this switch is a crucial step in achieving that goal.
“The steam to hot water conversion is a core enabling step in Cornell’s decarbonization work,” Tucker said. “All the preferred electric-based heating production equipment — earth source heat, ground source heat pumps, air source heat pumps [and] thermal storage — require a water-based distribution medium.”
In addition to improving efficiency, the transition also offers significant financial benefits for the University. With the current cost of steam heating distribution sitting at $1 million annually, the $270k hot water heating cost is a 73 percent overall cost reduction.
Implementing this transition across the 740 acres of Cornell campus is not without its challenges. Tucker said that the active campus — with buildings that require heat year-round and “cannot take sustained downtimes” — poses an issue.
According to Tucker, the University is looking at a 10-year timeline, expecting the hot water system to be fully implemented with a new electrified heating source by 2035.
Tucker noted that several areas on campus have already switched to hot water, including the new North Campus Residential Expansion facilities, the North Campus High Rises and Low Rises, the newer West Campus dorm facilities, buildings along Sciences Drive, portions of East Campus, the new Atkinson Hall facility and the new CIS facility.
Though the switch from steam to hot water is beginning gradually, Sarah Carson, the Director of the Campus Sustainability Office, noted in an email to The Sun that this initiative is part of a broader agenda.
“An exciting and important aspect of approaching campus decarbonization through the district energy system is that all of the buildings connected to it, not just our new buildings, are included in the transition,” Carson said.
However, some environmental advocates are pushing for a faster transition.
bethany ojalehto mays ’08, a former assistant professor and current organizer for Cornell On Fire, a climate justice organization, emphasized the project’s benefit, calling the conversion “very much needed and beneficial on multiple analyses.”
However, mays expressed concerns about the University’s pace, noting that at the Energy Engineering Seminar on Jan. 30, presenting officials gave vague answers about how much of the campus has already been converted.
“The people who happened to be at that talk couldn’t give an answer. They didn’t know how much of campus had been converted,” mays said.
She called for a stronger commitment to funding earth-source heat and shallow ground-source heat pumps, arguing that Cornell needs to "put their money where their mouth is" when it comes to decarbonization projects.
According to Tucker, the team is currently focused on expanding the hot water system, aiming to capitalize on the more manageable weather in the coming months while coordinating the necessary multiple trades — including site work, the construction of new Energy Transfer Stations and the completion of new building heating systems — to meet their 2035 carbon neutrality goals.
Tucker noted that the goal is for the switch to be seamless, with the main impact occurring upstream in the distribution system. While the transition continues, students and faculty are unlikely to notice any immediate changes in heating or energy use.
Amani Agrawal ’27 is a Sun contributor and can be reached at aa2747@cornell.edu.
