Bought this for our office space which is about 200 Sq. Ft.  I wanted to get something I knew would work because as they say "you get what you pay for" and we were not disappointed with this product.  As with any AC unit, it can be a bit loud when turned on full blast, but it doesn't affect meetings or anything like that (just white noise when you get used to it).  It sounds exactly like you would expect a window AC to sound like.  When put on low mode though it is extremely quiet.  We couldn't be happier, my only WARNING is with the adhesive seal that is provided, be prepared to do a lot of work to get it off if you install it.  That adhesive material is legit and does not just pull of.  You will need to use a lot of goof-off and elbow grease.  I decided not to use it due to this and just bought something else at the hardware store that didn't have adhesive on it.