Frore AirJet: a palm-sized PC might contain the future of gadget cooling

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There are largely two kinds of PCs — ones cooled by spinning fans, and ones cooled passively. A San Jose, California startup has raised $116 million in hopes of introducing a third way: a micro-electromechanical system that shoots air out of a solid-state chip, cooling with a device thinner and quieter than most fans can manage.

The company’s called Frore Systems, the device is called AirJet, and today it’s no longer just a cool demo at CES. At Computex 2023, Zotac has just announced it will sell an AirJet-cooled mini-PC for $499 by the end of this year.

I went to Frore’s headquarters to check it out — and to speak to CEO Seshu Madhavapeddy about what’s next.

The AirJet Mini was continuously spinning this rotor during my entire visit to Frore’s HQ.
GIFs by Sean Hollister / The Verge

First, temper your expectations: the “Zotac Zbox PI430AJ Pico with AirJet” isn’t exactly the kind of PC that sets most gadget lovers’ hearts aflame. It’s a barebones bring-your-own-SSD box designed primarily for edge computing, Internet of Things, and digital signage — the company’s biggest customers power displays in shopping malls, restaurants, medical clinics and the like, Zotac global marketing director Ernest Siu tells me.

The AirJet Mini, solo. Not pictured: required control circuitry and thermal interface materials.
Image by Sean Hollister / The Verge

Image by Sean Hollister / The Verge

Image by Sean Hollister / The Verge

It’s got a 7W Intel Core i3-N300 processor that nominally runs at 800MHz, with onboard graphics, 8GB of LPDDR5 memory, HDMI 2.0, DisplayPort 1.4, Gigabit Ethernet, and three 10Gbps USB 3.2 jacks, including another DisplayPort 1.4 over USB-C. The final units won’t have the fancy clear case you see above: they’ll be opaque black.

Not pictured: it comes with a VESA mount, too.
Image: Zotac

But when it comes to Frore’s technology, the specifics of this PC are a little closer to the point. What matters is that Zotac couldn’t quite build it without Frore’s technology.

Zotac has sold previously fanless Picos with even slower Intel Celeron processors, but not an Intel Core i3 — and this computer’s immediate predecessor, the PI336, was dinged for being unable to maintain peak performance even though Zotac turned its entire case into a finned heatsink.

When I walked into Frore’s headquarters, the company showed me two of the new Picos with and without AirJets, both running the same endless loop of the Furmark graphics stress test. The one without an AirJet was a stuttering slideshow at barely a single frame per second, while the other was cracking 9, 10, even 11fps.

As you can see in a couple comparison shots with a FLIR thermal camera, it’s because the AirJet model was actually ejecting heat.

Zotac’s mini-PC, without (left) and with (right) a pair of AirJet Mini.

Frore won’t let anyone see inside an AirJet device yet, so you’ll have to take the company’s word on how it works for now. Here’s Frore’s founder and CEO Seshu Madhavapeddy:

You have vibrating membranes inside the chip. When they vibrate they create a suction force that pulls air from the top through the dust guard into the inlet vents, and then pushes it down at very high velocities, and that high velocity air impinges on the copper heat spreader at the bottom of the chip . It gets saturated with heat by extracting heat from the copper heat spreader and then it exits sideways.

A rough idea of ​​how an AirJet works, according to the company.
Image: Frore

Madhavapeddy says the suction force is so powerful — 1750 pascals of backpressure, ten times that of a fan — that you can make a completely dustproof PC with integrated filters over its only openings. It’s so powerful it can apparently cool other components in a PC by sucking air past them, with a single AirJet Pro supposedly enough to cool a 15W Steam Deck handheld gaming PC despite offering a net heat dissipation of just 8.75W — the rest of the cooling comes passively because the skin of the device is just that much cooler with the AirJet’s breeze jetting past.

(You might notice the Zotac Pico doesn’t actually have top vents, because the twin AirJet Minis are pulling air through the vents on its sides instead.)

I’ll admit it’s a little hard to grasp how vibrating membranes can provide that much air pressure, particularly if they’re only consuming 1W of power as they do in the AirJet Mini, and Zotac’s Siu admits to me that the company hasn’t completely finished failure testing Frore’s tech. But I definitely saw multiple AirJets spitting out air, felt it with my finger, measured it with a thermal camera, saw it with a Schlieren flow visualization, and heard it with my ear up close. It’s actually not completely silent, but incredibly quiet compared to most any fan I’ve dealt with before.

Madhavapedddy admits the AirJet Mini isn’t for every kind of PC. It’s not a simple matter of replacing a fan with an AirJet — they also require dedicated control circuitry that has to be integrated into a system’s motherboard, and an internal layout that’s conducive (or easily adapted) to the airflow that makes sense. One of the biggest challenges is simply getting enough surface contact to make optimal use of the AirJet’s cooling, says Madhavapeddy, though that’s not unique to Frore’s solution.

The back of an AirJet Mini.
Photo by Sean Hollister / The Verge

But on the flip side, PCs with AirJet might not just be quieter — they could be built thinner as well, and/or with more room for battery, if they had a simple stack of copper heatspreaders and an AirJet instead of an array of heatpipes connected to fans. Adding more AirJets doesn’t increase the thickness of a device, it points out.

For now, the most important limitation is likely that an AirJet simply doesn’t provide as much cooling as competing solutions do, with a single AirJet Mini good for about 4.25W of cooling, with two required for the Zotac and three for a laptop. The Mini is the only AirJet in production so far, but the company’s also working on an AirJet Pro that’s roughly equivalent to the fan in a 13-inch MacBook Pro, and says the tech can easily scale up to larger future AirJets as well. In a Samsung Galaxy Book demo, he showed me a laptop managing higher sustained performance with several AirJets than it does with the stock fan.

Madhavapeddy says some of the lowest-hanging fruit is gaming smartphones, where a single AirJet Mini could make quite a difference. The company’s also prototyped 4K webcams, stick PCs, SSD enclosures, doorbell cameras, and LED light bulbs with the tech inside. While the Zotac PC is the first with an AirJet, he says Frore already has customers planning to announce other products later this year.

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