Recently whilst cleaning a Data Centre, we noticed high concentrations of dust on the air tiles. On closer examination, this dust was black. Also, it became thicker, the closer to the ACU, we cleaned. The dust was very fine, our vacuums struggled to remove it, so we had to wipe. The cloths went black. I then decided to do an air test, this showed high levels of 0.5µm particles in the cold aisle, which became higher the closer to the ACU we took the samples. Conclusion, the drive belts on the ACU were breaking down, causing particulate contamination in the room. We then found this dust on the tops of the cabinets, and on some of the equipment. “This shows the importance of a good maintenance programme, as contamination can come from within the data centre, and not just from outside sources” Stephen Yates.