"The Noctua NF-A14 IndustrialPPC and Noctua NF-F12 IndustrialPPC fans are perfect examples; continuing to meet and go above expectations. Since these fans are intended for 24V industrial applications, with the superior material used for the construction of the frames, they do have exceptional build quality. They can be run in 12V environments"
Ben Joubert - APH Networks.
Noctua industrialPPC fans review by APH Networks - Introduction & Conclusion.