This unit has been in continuous use for 7 months (7/24). It does a great job of equalizing the temperatures between the 1st and 2nd floors of our house. It is cool looking and quiet. It was off for about one hour for cleaning a month ago. Upon examining the unit during cleaning i observed that it is truly a well build and quality unit. The air equalization works with both A/C and heating. We do have a straight shot up our stairwell to the 2nd floor.