Hardly AV amps I guess,but it's very difficult to hear the fans on my KMA100's which have a far higher air flow than most AV receivers,so I'd be surprised if you have problems with a receiver,unless it's very close to your listening position.
It really depends on how sensitive your ears are and how quiet your listening area is.
I used to have a Nakamichi AV-10 amp and one night while watching a movie quietly (the family was asleep) I became aware of a noise from my rack. I worked out it was the Nak's fan and from that point on I became increasingly aware of the fan noise.
I eventually got rid of it and got a Denon 3803 (no fan) and now have a Marantz sr9300 (no fan). It has made a difference to me (though it's worth noting that I subsequently discovered the Nak had a reputation for fan noise).