There are many different brands of thru-wall A/Cs available. If you’ve shopped around at all you’ve probably run into at least some of the following: Haier, Comfort Aire, Garrison, Kool King, Arctic King, Carrier, Danby, Kenmore, etc. etc.
We at H&C are asked all the time about which brand is superior. The fact is, there is very little difference between brands when it comes to through-the-wall air conditioners. In fact many different brands are even made in the same factory. Almost all brands have the same features, general appearance, and reliability. As far as noise goes, there is no universal standard by which noise levels in thru-wall A/Cs is measured, so it is difficult to say which one is the quietest, though if the other patterns hold true, they are all probably quite comparable in noise levels as well.
If you’re wondering what kind of A/C to get for your apartment, give your local H&C rep a call to discuss. The correct size and style (window vs. thru-wall) is the more important thing to consider than the brand.