I have purchased 5 of these little Gems. Two originally when the A/C went out on a Saturday night in my son's house in New Orleans. They are very lightweight and cool down a 12X12 room quick. One of these first ones had the buzz, but I found out that if you shifted it slightly that went away (thought to be the internal blower hitting on the styrofoam divider). After the main A/C was fixed we put them in storage (just in case). Katrina came, and once again the units came out (cause the gen set wouldn't handle the Central unit). I bought another one, and the house was livable, if not comfortable...