Blowing fan noise?

[greenheckler]

I am a relatively new owner of a 2001 boxster and apologize in advance for potentially asking a question you all are knowledgeable of.

I heard what sounded like a fan blowing from the right rear side of the car today (by the side vent?). I have never heard that noise before and am a little concerned. It sounds like a fan blowing. Temperature gauge looked ok - around 180.

I had previously driven the car around town for about 10 miles and then pulled it into my garage to shut it off. After 10 minutes, I started it again to back it up on to the driveway when I heard this sound. I immediately shut off the car and waited 30 minutes. Started it again and no fan noise!

What is this?

Thank you