3D Printing Next-Gen Heat Exchangers January 19, 2017 | Alex Richardson

This is part one of a three-part series that highlights energy management innovations in the 3D printing space. These aren’t moonshots; we’re past that point in the Gartner Hype Cycle. They may not be as exciting as a fully-printed building, but these innovations or subsequent versions of them are likely to find their way into commercial spaces in your portfolio within the next decade. By making use of the advantages specific to additive manufacturing (another word for 3D printing), the researchers behind these devices have been able to make old inventions economically viable and new inventions possible.

Part two of this series is live! Read it here: 3D Printing Energy-Efficient Façades.

Last year, a research team at the University of Maryland received funding from the U.S. Department of Energy Building Technology Office to prototype next-generation heat exchangers that are 20 percent more efficient, weigh 20 percent less, and can be manufactured 20 percent more quickly than traditional manufacturing can fabricate current models.

A heat exchanger is an essential component of virtually every HVAC system. This is the device that facilitates the transfer of heat between the working substance (usually water) and the air that is pumped throughout the building, so improving the heat exchanger improves the overall efficiency of the entire system.

UMD’s heat exchangers are significantly more efficient than standard exchangers.

To accomplish this goal, the University of Maryland’s Center for Environmental Energy Engineering used an algorithm to predict new shapes and features that might be more efficient before employing 3D printing to rapidly prototype and test these predictions. The results were impressive.

“The 20-20-20 goal was essentially what we set out with, but over the course of three years, we looked at many, many different designs and prototypes,” CEEE director Vikrant Aute told Aquicore.“Most of these designs exceed the 20 percent mark.”

Aute explained that additive manufacturing made it possible for his team to test new designs immediately, whereas with traditional manufacturing the process would have been prohibitively slow. Additive manufacturing also allowed them to test shapes that would have been difficult or impossible to fabricate otherwise.

“One aspect that we are really exploiting here is the small hydraulic diameter, so we make the flow channels smaller,” said Aute. “What that really means in layman’s terms is in the same physical volume, you can pack more heat transfer surface.”

3D printing assists with innovation by allowing objects to go from plan to prototype in hours.

Surface area is one of the primary factors that affect the rate of heat transfer, so a higher surface area means that you can make lighter, smaller heat exchangers that perform at the same rate.

 

“The second aspect of our research is the sophisticated shape optimization,” Aute continued. “Conventionally, people have investigated round tubes and rectangular tubes, but our algorithm can come up with shapes that have significantly higher heat transfer performance.”

When the team’s initial research was published, their heat exchangers had only been tested for cooling up to 10 kilowatts – about the level needed for a small home air conditioner. Aute’s team is working to demonstrate that they can be used in heat pumps, which are used for both heating and cooling, and to scale them up to commercial levels of operation.

There are challenges involved, to be sure. Aute highlighted the problems that 3D printing still has with competing on price against traditional manufacturing techniques and the difficulties involved with physically scaling a technology up. He mentioned that the team is considering modularization to overcome the latter issue: Instead of making the exchangers bigger, it might be possible to arrange lots of them together to accomplish the same task.

Challenges aside, the team expects their innovation to find its way into commercial production within the next five years.

Read part two of this series, 3D Printing Energy-Efficient Façades, look out for part three on Friday, January 27, and join our mailing list to get weekly updates!

 

About The Author

Alex Richardson is a staff writer at Aquicore. He writes about green policy, energy efficiency, and innovation that affects commercial real estate. Alex.Richardson@aquicore.com.