I too was also just in that area (the upper Fridge Vent).
I got back home from a short trip to Yuma, AZ, and when I turned the fridge off to unload the food I heard the fan that is mounted on the rear of the fridge. Now I have a serious hearing loss, but it was even loud to me.
After sliding the fridge out, and removing the baffle, I found the single 12VDC fan that is used for ventilation and controlled by the thermostat attached to the upper fins. I researched the Part Number and found that it was rated at 42db sound level and pushed 60cfm of air.
It is a standard size (92mm), so I ordered two 92mm computer fans that were rated at 1/4 the noise level and delivered 30cfm each. Mounting the two fans also spreads the airflow over the entire width of the fins instead of one side as the OEM fan does.
I removed the bracket to which the OEM fan was mounted, and removed the OEM fan. The bracket is already configured for two fans, so my only modification was to enlarge the fan mounting holes so that I could mount the new fans with rubber grommets to further reduce the sound/vibration.
Now even my wife (who has good hearing) cannot hear the fans when they are operating.
A great project to complete while waiting for the next trip (CA Rally in Petaluma, CA)
2013 Rockwood 8289WS
Mods: Central Vac, PI EMS-HW50C, 2025RV, (2) SCS225 Trojans, PD9260, Awning Remotes & LED Lights, Eliminators, External Water Filter,, Intellijacks
2008 RAM 3500 Cab&Chassis Hauler Bed, B&W Companion Hitch
All My Modifications are at this link: