We have a 2006 WW FSC2800. Our O’nan 5500 is located on the street side in the kitchen area. We’ve never had an issue with noise. In fact I consider it more as white noise.
We often party late, run the A/C during the heat of the day, and take a nap during the hot afternoons. The slight rumble and sound of the A/C and gen helps cut out outside noise.
We also used the Gen-X exhaust riser system (I think that’s what their called). This vents the gases up above the roof of the trailer. This is a safety factor and a courtesy for your neighbor when camping close.
Hap