I asked myself the same question early this morning when i had a look at the motor and saw they where curved. When i set the motor running in reverse out of the fan box i could feel the differance in performance but when i put it back in the box and conected all the pipes its still up to the job its supposed to do, not a bad little fan if i do say so myself to say its going the wrong way.Thanx for the heads up on the fan though , i totally overlooked the direction thing,