One of the quietest portable ac units that we have found is the Honeywell MN12CES 12,000 BTU Portable Air Conditioner with Remote Control – Black/Silver
This type of noise can be an annoying humming noise or a white noise. It can also be a clunking sound when the compressor engages. Most products are very much alike.
It is hard to think bad of anyone talking negatively about noise levels since this is the normal reaction. Most portable units report noise levels that are from 50-56 db. This is a little bit less than normal conversation which is around 60-65 db.
The relative likeness among different models and makes is easy to understand. Manufacturers usually see that noise is an important consideration for many buyers and have done their best to reduce it as much as possible. Although there is just a small amount of of variation between noise ratings, users reactions will vary a great deal even from reviews of the same system.
We went through all of the reviews of the most popular and highly rated portable systems and read them along with looking at manufacturer data sheets. We only think about models that have a 4-star rating or more. Most of these had more than 10 reviews each.
The Honeywell MN12CES 12,000 BTU Portable Air Conditioner with Remote Control – Black/Silver is the quietest option that we have discovered. If you are searching for a quiet system, we recommend this one.