Is it safe to clean the ps3 air vents with a fan ?

May be...

just a regular fan..

Yeah... I don't know how it would harm it at all. Besides, the air vents use fans to keep the heat out...

It's not the best way to clean the vents, the best way is to use a damp rag of some sort. You don't want any dust blowing into the hard drive.

Yeah i do it too, but be carefull to not let dust get in the harddrive.

too much dust could make your ps3 malfunction