Antec Phantom 500W
 

We have just our review of the "Antec Phantom 500W". Phantom 350W was a
completely passively cooled PSU, but with Phantom 500W Antec has chosen to
add a fan, in other words it is not completely passive. Or to be even more
precise, it is passive as long as it doesn't need better cooling and only
then the fan starts to spin.