This is a commonly asked question by Caravan/RV owners; however, it is unfortunate that Caravan Aircon manufacturers do not provide dBA ratings in their product model specifications.
We can say that we only sell high quality Air Conditioners from premium brands in the RV industry. The only time we have encountered an issue with noise is when the install was not undertaken correctly which can cause a rattle. However, if you ensure the install is done properly, there will be no issues with any of our RV Aircon units being too noisy.
One other piece of feedback we can provide, is that the two latest Dometic Aircon models (Harrier and Ibis4) have inverter technology within the compressor, meaning any vibration is minimised. Our customers and our internal testing suggest that when these models are operating at high cooling mode, the noise level is very, very low, making them arguably the quietest Aircon models in the market.