This should come as no surprise that Noctua offers an even higher performing tier level of fans, called the IndustrialPPC (Protected Performance Cooling) series. As you can imagine, fans have plenty of uses not only in personal computers, but in even harsher, wetter and dusty industrial environments.

For example you can get these fans from Noctua even with an IP67 (Ingress Protection) certification which means they are dust and water resistant to a certain degree; the first number is for protection from object intrusion with 6 indicating total protection from dust. Then the second number is for water intrusion or exposure and 7 means that the fan can handle being under 1 meter of water for up to 30 minute.