Evaporative cooling is far from new – it has been used to cool living spaces and drinking water for centuries – but the Matter of Tech Lab at Cornell Tech has come up with a new way to deploy an old idea.

Lab director Thijs Roumen, assistant professor at Cornell Tech and the Cornell Ann S. Bowers College of Computing and Information Science, and two lab members have developed CeraPiper, a fabrication system that creates customized sizes and shapes of ceramic pipes via extrusion. The pipes can be shaped on demand, fitted together and filled with water for environmentally friendly cooling.

“This custom variability, being able to tailor each individual piece to the specific properties that you’re looking for, is something that we feel adds a lot of value,” said Ofer Berman, former postdoctoral researcher at the Matter of Tech Lab who presented “CeraPiper: Custom Extruded Ceramics for Evaporative Cooling” at the Association of Computing Machinery’s Symposium on Computational Fabrication, Nov. 20-21 in Cambridge, Massachusetts.

Berman is now an assistant professor at the Technion Israel Institute of Technology. Also contributing was Ethan Zhi Ming Seiz, a Bowers Undergraduate Research Experience summer intern.

In evaporative cooling, liquid is transformed into a gas and reduces the temperature of its surroundings via thermodynamic energy exchange. Unglazed ceramics are particularly suited for this process, as they absorb water through capillaries and release vapor through pores in the material.

Roumen and Berman began discussing the possibilities of this system years ago, during Berman’s postdoctoral research in the Matter of Tech Lab.

“Ofer was really interested in the tension between mass production and custom manufacturing, and what we ended up doing here really sort of sits at the sweet spot between these two,” Roumen said.

CeraPiper employs a commercial pugmill machine used in extrusion manufacturing, extending the mill’s functionality through the use of a dynamic custom die that can be programmed to produce varying diameters, exterior profiles, and lengths of pipe. The pipe can be bent and otherwise shaped following extrusion, while the clay is still malleable, before firing at 900 degrees Celsius.

Different sections of pipe can be fitted together to create cooling structures tailored to the space where they will be used.

“We had to do a lot of ‘engineering’ – although I’m not an engineer – to make it work,” Berman said. “There are a lot of moving pieces, as well as a software tool behind it all that controls the sequencing of the extrusion.”

Seiz developed the computer-aided manufacturing program behind CeraPiper, which produces lengths of pipe in just seconds. And another plus: Extruded clay can be put back into the milling machine and reshaped if the original form isn’t exactly correct, minimizing waste. 

“Because of the speed, it’s actually possible to quickly iterate a design, look at it and evaluate whether it’s good, and then just start over again if necessary,” Roumen said.

The researchers tested CeraPiper by measuring, over 60 hours, the temperature in two wooden chambers – one empty and one containing lengths of CeraPiper pipes. The chamber with the pipes had consistently lower temperatures and an elevated relative humidity (8-10% higher), indicative of evaporative cooling.

CeraPiper’s big advantages are the speed with which the pipes can be produced and the customizability, Roumen said.

“You can get customization but no speed with 3D printing,” Roumen said. “And you can get very high speed but no customization with mass manufacturing. CeraPiper is at the sweet spot in between.”

Roumen said the group is exploring the potential for more elaborate dies that would create more varied shapes, “sort of expanding the design space of what evaporative cooling structures could look like.”

Roumen especially likes the fact that CeraPiper, which employs a centuries-old principle, represents “taking a small step toward battling climate change. And it works shockingly well.”

Financial support for this work came from the Bowers Undergraduate Research Experience and the AOL, Inc., Fund of the Cornell University Foundation. Berman’s postdoctoral tenure was funded by the Sidney and Vivian Koningsberg Lectureship fund and the Jacobs Institute.