Progressive Cooling: A New Way to Cool LEDs

The Berkeley, Calif.-based startup says it has combined micro loop heat pipes and silicon wicks to make a passive cooling system that could help LEDs get a lot smaller without overheating.

Jeff St. John June 05, 2009

Jeff St. John

Senior Editor
Greentech Media

Reporter covering the green technology space, with a particular focus on smart grid, demand response, energy storage, renewable energy and technology to integrate distributed, intermittent green energy into the grid.

Progressive Cooling Solutions is taking a Russian technology for keeping satellite electronics cool and bringing it down to earth to cool LEDs.

The Berkeley, Calif.-based startup has raised $1.5 million in seed funding from Siemens Technology-to-Business to mesh two technologies – micro loop heat pipes developed by Russian scientists, and what CEO Tom Griffin calls a "silicon wick."

That's a silicon membrane with pores about 5 microns wide and 500 microns deep, developed by company founder and CTO Ahmed Shuja while at the University of Cincinnati.

The idea is to transfer a device's heat to a liquid, turning it to vapor, then carry it in a tiny pipe up to a couple of meters away to a condenser that turns it back to liquid, Griffin said.

That would usually require a pump, but the "silicon wick" that Shuja has made passively powers the process through capillary action, he said. In short, it's a no-power heat-transfer device.

"It's a neat thing – it's novel, and it's small," he said.

Progressive Cooling has developed prototypes with $1.5 million in seed funding, primarily from Siemens Technology-to-Business Center, the German industrial conglomerate's seed funding incubator.

Now, he said, it's seeking a $3.5 million Series A round for pilot production of systems aimed at the light-emitting diode (LED) market, where dealing with heat is a major concern.

Heat is a major limitation for making LED lights smaller and more compact because, unlike incandescent light bulbs, they can't dissipate the heat they produce into the air. Instead, heat that isn't turned into light is conducted directly into the material of the light itself, which causes major problems if it can't be dissipated somehow.

Several startups are seeking to develop better ways to cool LEDs, including Nuventix, which has raised $32.5 million so far to commercialize its system of cooling via jets of air (see Green Light post).

Alessandro Zago, director of venture technology for Siemens TBD and a Progressive Cooling board member, says his company's technology can outperform such active cooling systems. As an example, he said it could allow a 20,000-lumens LED light that now sits in a two foot-by-two foot structure to be shrunk down to a four-inch-square size.

Griffin said that's a key goal of LED manufacturers that want to be able to pack as much light into as small an area as possible. "That very small footprint is extremely important to differentiate yourself in the space," he said.

Progressive Cooling is targeting LED lights for industrial, commercial and outdoor uses, he said. LEDs offer far better energy efficiency, but their high cost has so far held them back from more widespread application (see Lighting the Way to Efficiency and DOE Says LEDs Can Shine in 12 Markets).

Progressive Cooling is eyeing other markets for its technology, including cooling servers and solar panel microinverters, Griffin said.