Campus as lab: At Malone center, Yale taps into a ‘zero-carbon’ future

A historic renovation at Yale’s Malone Engineering Center marks a key first step in the development of a new networked geothermal exchange system.
The Malone Engineering Center

The Malone Engineering Center is the starting point for a new, networked geothermal exchange system that will eventually serve lower Hillhouse Avenue. (Photos by Dan Renzetti)

As students and faculty toil away on research projects in the laboratories and classrooms of the Malone Engineering Center, the building itself is playing a key part in a university-led experiment.

Malone, located at the intersection of Prospect and Grove streets, is the starting point for a new, networked geothermal exchange system that will eventually serve all of Yale’s buildings on lower Hillhouse Avenue, an area that is slated to undergo a transformation over the next 10 to 15 years. The facilities, between Trumbull and Grove streets, are all going to be renovated or replaced as part of a historic series of investments in the Yale School of Engineering & Applied Science.

Sustainability is an integral part of that vision. The networked geothermal system, part of the university’s ambitious plans to achieve “zero-carbon” status on campus by 2050, will tap the earth’s relatively constant temperature to heat and cool piped-in water that can then be used to heat and cool the buildings. Additionally, the university plans to electrify all the laboratory and humidification equipment in these facilities.

Malone will provide proof of concept and key lessons learned.

The Malone project is an opportunity to demonstrate to our community of scientists, researchers, and innovators that they are not going to feel an impact on their work as a result of these infrastructure changes,” said Julie Zimmerman, Yale’s vice provost for planetary solutions. “This is a demonstration that we can do this so that we can then go confidently to scale delivering world class research facilities while meeting our climate goals for the university.”

Later this year, drilling rigs will show up outside Malone to begin digging some 70 bore holes as deep as 800 feet into the ground. By the time the project is completed, likely in summer 2025, Malone and all the equipment within will be completely electrified.

This Malone electrification project will stand alone for many years but will ultimately be tied into a greater effort in the lower Hillhouse area,” said Anthony Kosior, associate vice president for facilities and campus stewardship. “While geothermal is an essential aspect of it, the electrification of the entire building is another key aspect and represents one of the largest challenges.

We have to take this all the way — we can’t just electrify the heating component,” he said.

View of lower Hillhouse from a bridge over the Farmington Canal Trail.
The long-term ambition is to take historic lower Hillhouse to a zero-carbon state.

You’re just using the earth’

Three years ago, Yale announced it would reduce actual carbon emissions on campus to zero as soon as possible and no later than 2050. Achieving that goal will require a continued shift toward energy efficiency and clean energy. A key part of the strategy is the creation of centralized geothermal plants and electric heat pumps.

Currently, centralized energy plants on campus burn natural gas to generate and supply steam and electricity to buildings. The steam is used to heat buildings, as well as to support specialized process needs within some buildings like humidification and washing equipment.

Geothermal systems don’t require the use of fossil fuels. Rather, they utilize a network of piping to circulate water through the deep boreholes in the ground, taking advantage of the relatively consistent temperatures found underground to act as a heat “sink” in the summer and a heat source in the winter.

Geothermal heating and cooling systems aren’t new to campus. Kroon Hall, the flagship home of Yale School of the Environment, built in 2009, was the first building on campus to install geothermal wells. Geothermal systems are also in place at the Greenberg Conference Center and at Pauli Murray and Benjamin Franklin colleges, Yale’s two newest residential colleges. There are also plans to install geothermal systems as part of the redevelopment of upper Science Hill that will eventually serve new and existing buildings in the area. The lower Hillhouse project, however, will be one of the university’s first networked systems that serves multiple buildings simultaneously.

While the systems vary in design, Malone will use what are called closed-loop geothermal wells. Pipes filled with fluid will go down into the ground in each borehole, form a “U” at the bottom and loop back up to the surface.

You’re just using the earth and whatever water might be available as a heat exchanger,” said Julie Paquette, Yale’s director of engineering and energy management and the project planner.

A type of electric heat pump called a heat recovery chiller located on Malone’s penthouse floor will push and pull water through the looped system, providing both hot water for heating and chilled water for cooling.

This heat recovery chiller will be dedicated to Malone, but in the future, there are going to be multiple units that will be installed in a central location, 19 Hillhouse, which isn’t built yet,” Kosior said. “Once it gets fully integrated into the greater network, this heat recovery chiller will likely become a backup to those other machines.”

The facilities team decided to start with Malone, which was built in 2005, for several reasons, Paquette said. They were very familiar with the building’s workings because they’ve done considerable energy conservation work there. It is a relatively new building compared to others on that block so it can be optimized more easily.

And while it has both wet and dry labs, the building is fairly modest in size compared to some other research facilities.

Malone offers a more manageable scale,” Paquette said, “but the full spectrum of challenges.”

Laboratory and research facilities are especially tricky to convert. One reason, Paquette explained, is that they are highly energy intensive. They need to pull in high volumes of outside air to adequately exhaust spaces with chemical and biological hazards. And that air must be conditioned for comfort, as well as to maintain stable temperature and humidity levels in research areas.

These buildings also use steam directly for washing and sterilizing equipment, and for humidification. Considerable research and testing will be required to replace that equipment with equally effective equipment that does not use steam directly.

A third challenge, related to hot water temperature, is one shared by many Yale buildings. Currently, building heat is primarily provided by 180-degree hot water. But geothermal heat pumps don’t easily generate water that hot. They can, however, deliver water heated to 140 degrees or lower.

As a result, “every building will require slightly different modifications to use lower temperature heating hot water,” Paquette said. “It might mean new windows or insulation to reduce heating needs, it might mean resizing heating coils in mechanical equipment so that it can deliver the same amount of heat with lower-temperature hot water, and in almost every case, it means eventually decommissioning steam to hot water heat exchangers.”

Challenges to overcome

The Malone project is currently in the pre-design phase, as the Office of Facilities team establishes the feasibility and scope of work. Still under study is where to locate the boreholes, and what type of drilling methods to use.

The planning team initially thought the boreholes could be located beneath the Farmington Canal Heritage Trail, which runs alongside Malone, said Mike Ghilani, a senior mechanical engineer working on the project. But there turned out to be too many obstacles, including underground utilities and rights of way. Now they are considering a small plot of sparsely wooded land on the far side of the canal. But due to the spacing requirements for the wells, Ghilani said, “it will be a challenge to get all 70 wells in there.”

A stretch of the Farmington Canal Heritage Trail next to Malone Hall
The Office of Facilities is considering drilling boreholes for the geothermal system on a small plot of land alongside the Farmington Canal Heritage Trail.

It’s a puzzle the university will face throughout lower Hillhouse, an urban environment without much open land. One potential solution being considered is the use of a drilling method developed by the oil industry that involves sending a drilling rig into the earth from a single drill point (about the size of a single parking space) and, once more than a hundred feet down, digging  about 20 wells shooting out diagonally and in a 360-degree ring.

Now you’re accessing land well underneath existing buildings which you would not have been able to access otherwise,” Kosior said.

The work that will be required inside of Malone is no less daunting. The team has to figure out where to put all the piping that will run from the boreholes to the heat recovery chiller on the fifth floor.

Then there is the matter of electrical capacity. Electrifying the entire building means it will need more transmission capacity. That, the project team says, will require adding a transformer outside.

And various pieces of equipment that currently rely on the piped-in steam will have to be replaced. A steam generator located in the penthouse, for instance, humidifies a small laboratory space. It will be replaced with an electric adiabatic humidifier, but that technology will require longer pipe lengths, which presents yet another spatial puzzle given the maze of piping that already fills the penthouse.

Finally, there is the matter of the building’s two autoclaves and two glassware washers, which use steam for heating and sterilization. The four pieces of equipment sit side by side in a narrow room with little space to spare. Paquette said they are meeting with researchers to talk through electric options for the washing equipment, which must have adequate capacity but also be able to fit in the limited space.

Ultimately, the Malone experiment will demonstrate crucial pathways forward for creating state-of-the-art innovation spaces and research facilities at Yale Engineering in ways that also help drive the university toward its zero-carbon goals. When conversion of the district is complete, it will be worth about 5,500 metric tons of carbon dioxide equivalent, which roughly equates to annual CO2 emissions from 720 homes.

The lower Hillhouse ambitions are huge,” Paquette said. “To be able to take a road that’s so beautiful and historic to a zero-carbon state? That’s really, really exciting.”

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