We had the Mitsubishi unit installed in our sunroom. You cannot hear it running. It keeps the 12 x 24 sunroom cool and also keeps the 16x18 utility room cool. This is amazing to me since there is only a 3' door connecting the rooms and it is as far away from the unit as possible. It was $3500 installed, expensive, but worth the money. As I said above you cannot hear it running.
We repainted all the sunroom window frames last fall. There are thirteen windows. It was 90+ outside and inside and all windows were open. We turned the unit on, installed the handles, and cranked all the windows closed. It was cool within ten minutes.
Worth the money.
RSKY