“ gives us a lot of surface area, which is hugely beneficial,” Ternus says. Making those holes deep gets back to the first principle: more surface area means better dissipation.
“We wanted free flow through the channels no matter the orientation,” Ternus says.įor the Pro computer, that new case design helps the new Pro get “about 20 percent more airflow” compared to the Power Mac G5 that precedes it. Hemispherical holes, however, work the same no matter which way is up. Rotating the thing 90 degrees would mess with the air flow through those fins. “A common solution, passively, is to have a finned enclosure, a heat sink. “It’s very easy to get air trapped in channels,” Ligtenberg says. “And we go through testing to issue the lifespan of the system.”ĭrywall demolition? That might make enough dust to cause problems, but an editing bay at Pixar shouldn’t gum up Pro. “We create geometries that can deal with a certain amount of material getting on them,” Ligtenberg says. “We don’t have a need for that,” Ternus says. The Pro and Pro Display do not have these kinds of filters. One advantage of noisy fans: They can handle the impedance (resistance) caused by filtration systems, which some computers use to keep debris away from the vital components.
A ton of analysis goes into figuring out how to optimize for that.” “We want to get really great performance where, you either can’t hear it, or if you can hear it, it’s kind of a pleasant noise. “You can have something at a certain SPL that sounds really good, but you can have something that’s actually at a lower SPL that grates on your nerves and sounds really awful,” says John Ternus, VP of Hardware Engineering at Apple and head of the Pro and Pro Display’s development. Something loud but pleasantly pitched can be more tolerable than something quiet but irritating. “There’s a bit of math behind it, but you can create broadband noise instead of total noise with that technique.”Īpple engineers have to find creative ways to exploit the laws of thermodynamics. In this case: “That borrowed almost entirely from automobile tires,” Ligtenberg says. Noise is a major factor in the design of modern machinery. So you don’t get huge harmonics that tend to be super annoying.” “They’re still dynamically balanced, but they’re actually randomized in terms of their BPF. “Years ago, we started redistributing the blades ,” he says. Since most off-the-shelf fans would be too loud, Apple designs them internally.
Ligtenberg’s group built the Pro’s fan system-three axial fans in the front, with a blower in the back. Before that, he had a Piper straight-tail Lance, PA32R-300). “I fly a Beechcraft Turbo Bonanza, B36TC,” he says. His name is on dozens of the company’s patents, but he’s especially interested in how air moves. Among those engineers is Chris Ligtenberg, Senior Director of Product Design.