Albott 36 inch 5.4 amp 500 watt DC variable speed industrial Fan. (Long ramp up to full power)

Got this fan off Amazon. you have to fully assemble the fan yourself. you have to assemble the frame the motor and the moter brackets the fan blades all the wiring ext. I got it assembled but it wasn't smooth sailing. the frame and wiring was easy. getting the motor with the motor brackets inside the fan casing was a major pain. no question the motor mounts are to long. it took so much force to get in place that the brackets bent causing the fan blade assembly to pitch downward i had to make a few modifications get everything to seat right. with that issue and doing a freed air test run with juat the motor and fan blade assembly and the controller before assembling everything else I just wanted to verify it worked. with no air flow restriction free air. it did 37 mph which is insane. These are the performance numbers I have measured. Max air speed at grill 30.3 mph(measured off camera)17 mph at 8 feet. at the lowst speed 5 mph and 2 mph at 8 feet. 422 watts and 5.4 amps. Low speed only pulls 6 watts. 0.67 power factor. I think its low due to the nature of DC motor and controller. the other odd behavior is the 1min and 20 second slow build up to max speed and power. company gave me a $60 refund due to my issues. this means I only paid $254. that is incredibly cheap for a fan with this much fan speed adjustment between 100 and 900 rpm abd the blisting performance. this thing hits 30 mph and its really not that loud. 76 db measured at 3 feet.