Air cooling

Air cooling is the traditional method of keeping servers from overheating by blowing chilled air across them. It is the legacy baseline of the data center: cheap, well understood, and dominant for decades of general-purpose computing. It matters now precisely because it is being outrun. AI racks concentrate far more heat into the same footprint than air can practically carry away, so the metric that counts is the point where moving air stops being enough and liquid must take over.

If air cooling runs short of headroom, the consequence is not a shortage but obsolescence: facilities built around it simply cannot host dense frontier racks and get relegated to lighter workloads. That drives retrofits and liquid-ready new builds, and pulls the exposure toward the thermal-management names — Munters, Modine, Comfort Systems, Envicool and fan specialists like Sunon and ebm-papst — who sit on both sides of the transition, supplying the incumbent kit while racing to sell what replaces it.