It’s summer in Brisbane, and the team at Smith & Sons Auto Repair is sweating through another muggy afternoon. The garage feels like a sauna, tools are slipping out of greasy hands, and everyone’s moving slower than a flat tire. The owner, Mike, tried everything—box fans, portable ACs, even propping the doors open. Nothing worked. Then, a buddy suggested large industrial ceiling fans.    A week later, Mike installed three fans with wide, swooping blades. The...