Who makes fans for AI data centers

Tray and chassis fans sit alongside the heatsinks and vapor chambers (4.17) as the air-cooling half of a rack's thermal design, and they remain necessary even in a liquid-cooled rack-scale system, since cold plates (layer 5) typically cool only the GPUs and a few other hot components while the rest of the tray — memory, VRMs, networking silicon — still relies on airflow. That makes fans a hybrid-cooling-era component: as more of a rack's heat load moves to liquid, fan count per tray can fall, but it doesn't go to zero, and the fans that remain often have to move air through a more crowded, liquid-plumbed chassis than before. For investors, this is a mature, competitive component category without a strong bottleneck, so the more relevant question is the net demand trajectory as liquid cooling adoption rises — fewer fans per liquid-cooled tray, but more total trays being built.