When I first got my Waco 110, it used to drive me crazy at night with its' seemingly never ending on and off cycles every night. I used to keep turning the temp lower and lower to reduce time between cycles and still the cycles never stopped (see a pattern developing here). Second time out, same problem! Okay, I should say here that I just went solar on my Pop-up-that is added a new house battery, comptroller/wiring, and frig- the whole thing after almost 8 years of my 3/1 propane world-maybe this was just part of the solar learning process. Boy sure is real noisy at night and my food is sort of cold in the morning and then gets colder as the day goes on-more clues here!
I headed out on my third run determined to figure this thing out and found a camping spot at Eagle Lake to be close to home if things went wrong. Well at first my food (in between cycles)was not staying very cold-hmmmm, something still wrong here-thermostat maybe, could be thermcouple -what ever ? (was thinking like it was my old 3 and 1 propane one and not in the new world of compression frigs and solar power) ; then it went dead-like no power, no cold. Headed right from my camping site to my one and only NE California RV dealer and repair shop with visions of high repair costs-maybe even a new frig.
Well, after I described the problem to them-first thing they said-did you check your batteries of late? No-when did we put that frig in for you? Oh, hmmmmm. I remembered then somewhere hearing/reading that when you up graded to two batteries they both should be the same age. Did not do that, to much more $, it will work with one new and one old battery-my bad,my fault. Check the batteries-one not to good-one more or less okay! So I'm running every thing one one battery-no wonder my charge seems sort of work during the day and seems to die at night! Replaced both batteries and things seem allot better, more power, cold food, lights and allot less noise and more sleep.
Sooo, that's a long answer to your question of how noisy they can be. Now if you are cheap and don't do things right the first time (like me)--they can be very noisy and the moral to the story is ----spend the money, find someone that knows what they are doing so you do it right and if you have any questions drop a line here and maybe get the answer you need.
Smoke