We have the fridge in the slide. The fan that was in there is 90mm box fan, and very noisy in our case. Talked to Host, they recommend taking it to the local dometic dealer.. Doing research online shows that they simply replace the fan with an identical fan, which also can be noisy.
So I order 2 of the silent computer 90mm box fans, pulled the old fan out, soldered the two new fans in place, and put them in.
Now it's dead quiet.