Yes it can be used without the fan/fans, but as said, really all depends on the temps. May not be ideal, but if only watching movies, or web browsing then can't see why not.
I often run my watercooling without my fans on, but then again my radiator is far better then the corsair one.
So you won't get brilliant temps, but yes it can be done, but would'nt advise it if your doing intensive stuff. Idle, and light load only.