It functions as it should. I'm not able to own it long enough to tell you how efficient it is on my electric bill. It is sturdy and it's not very loud at all. Instalation was easy although I had to make some modifications. The reason for the 4 stara instead of 5. But I will yell you this, it blows COLD. and I'm hoping it'll make a difference this summer for the room I out it in is the hottest year round.