If you can't fish it out with a magnet it could take a bit of disassembly to get it out. Otherwise, as Paladin says, it depends on where the vent leads. Other than rattling the only concerns are getting into the blower (this is for a vehicle, right?) or jamming a blend/vent door. Most of the time debris in the vent systems is only noticed when the system is opened for access to something.
it may not be an issue.. take a piece of string with a small magnet tied to it and drop it down there should fish it up with a few tries..
kinda depends on where the vent leads
It may be sitting on the cabin air filter. The cabin air filters are usually located behind the glove box. No, it wont cause any damage at all.
To look at your cabin air filter, open the glove box, take everything out of it, then slip off the dampener (the thingie that makes it open and shut smooth and slow so it doesn't just fall open). Once the dampener is off, the glove box will open far enough to take off the little cover behind it for the air filter then pull the filter out.
My son dropped a paperclip down the vent any ideas on how to get it out and if not is it dangerous?
