A fan is a fan. Some CPU fans can be on the small size, like 60mm instead of a minimum of 80mm used on a case, but you could certainly figure out a way of mounting it. The other thing about fans in general, the bigger the fan, the more air it can move at slower speeds, meaning they are usually quieter. Some applications such as cooling a CPU might have a certain airflow it needs to achieve in order to remove heat fast enough at max load, but a fan is a fan, they move air. You just need to know how much air needs moving and if you have any noise concerns. Some people's PC sounds like a hair dryer running they are so loud.