Quietest A/C

Of the ones you listed, I would say go with the Coleman or Dometic. The Advent is a Chinese knock off. Check reviews on line before you buy.

Dometic's heat pump which goes by a different brand name.

We had a Coleman that did not last one year, the Dometic lasted 14 years of desert heat, the Colemsn was only good for temperatures less than 85f the Dometic keept cooling even when we had 118f the interior was cold, my C has about 1 1/2 inch insulation and that helps, replaced Coleman that quit working with Dometic.

navegator

navegator wrote:
We had a Coleman that did not last one year, the Dometic lasted 14 years of desert heat, the Colemsn was only good for temperatures less than 85f the Dometic keept cooling even when we had 118f the interior was cold, my C has about 1 1/2 inch insulation and that helps, replaced Coleman that quit working with Dometic.

navegator

Coleman sales their name to any whom wants to buy it. Who knows who actually made the Coleman thing.

To answer your original question without making value judgments, we have owned 3 of the 4 you listed and the Coleman (@ 15K) was by far the quietest.

We have two Coleman on our 5th. They are a little noisy, but I've definitely had louder ones.

Have three 13.5's on 13 journey Winnebago MH. COLEMANS.. Would not be my first choice. Replaced the exhaust blades three time and still quite noisy. Not sure about the rest ! I would do some research.

The Coleman in our last Fiver was quieter than the Dometic in our present fiver.

Newer Dometic is noisier than the three Colemans we have on three different RVs.

I can tell you our Coleman is darn quiet on the outside. Standing next to the RV, I can't tell it's on. Inside, however, DW complains of the fan noise on high. I think it's more of a vibration than wind noise and could be reduced if I had the inclination to look into what is causing the vibration.