"The Cooler Master Cosmos 1000 case comes with four 120mm fans pre-installed inside of the case. Two of these fans are mounted on the top of the case, which will blow the hot air that rises to the top of the case out of the case quickly. There is also a 120mm fan mounted on the rear of the case, above the I/O panel, that also blows more of the hot air out of the case. The placement of these fans seems like a great spot due to the fact that the CPU heatsink will be placed nearby. There is also a fourth fan that is located on the bottom of the case and is sucking cool fresh air into the case, but has its own special housing. The best feature of these fans is the fact that they are silent, operating at an advertised 17 dBA, while still running at 1,200 RPM."