Heat exchangers are everywhere—in air conditioners, refrigerators, cars, airplanes, data centers, and even in your phone.
These devices move heat from one place to another by allowing two fluids to exchange heat through a surface.
Despite how common they are, their basic design hasn’t changed much in decades.
Now, researchers from the University of Illinois, led by Professor Bill King and Professor Nenad Miljkovic, have taken a huge leap forward by redesigning heat exchangers using 3D printing, also known as additive manufacturing.
Their breakthrough work was recently published in the International Journal of Heat and Mass Transfer and has shown that 3D-printed heat exchangers can work 30% to 50% better than traditional ones.
The reason heat exchanger design has stayed the same for so long isn’t due to lack of ideas—it’s due to manufacturing limitations.
Traditional manufacturing methods simply couldn’t create the complex shapes needed to improve efficiency. “The heat exchangers we use today look almost the same as those from 30 years ago,” said King. “The designs are limited by what the machines can make.”
But with 3D printing, those limits disappear. It allows engineers to design and build nearly any shape they can imagine—shapes that wouldn’t be possible using older techniques.
This opens up the possibility for intricate designs that guide fluids in new, more efficient ways, combining wide pathways that reduce resistance with narrow ones that boost heat transfer.
In collaboration with the U.S. Navy, the research team created and tested a new kind of heat exchanger using these techniques.
Their device handles what’s called “two-phase” cooling—where a vapor enters, cools down, and leaves as a liquid, giving up its heat to water that flows through the exchanger. This process is used in systems that need high-performance cooling, such as naval ships or advanced electronics.
Because of its 3D-printed structure, the team’s heat exchanger is smaller, lighter, and more powerful than conventional versions. According to Miljkovic, this kind of design can help create more energy-efficient systems and allow powerful cooling in mobile systems like cars, ships, and planes—places where traditional bulky systems wouldn’t work.
To design the best shapes, the team also built advanced computer models that could test thousands of potential designs virtually before printing. They worked closely with companies focused on energy efficiency, like Creative Thermal Solutions Inc. and TauMat Inc., to bring their ideas to life.
With this success, the team plans to keep exploring even better designs, using their powerful modeling tools and 3D printing to create the next generation of high-performance heat exchangers.
