You may have to adjust the position of the extruder. I mounted the shroud so there is about a 5mm distance from the tip to the nozzle to the lowest part of the shroud. If you adjust the position of your extruder, make sure to take precaution and set your z offset so that the extruder doesn't crash into the bed. I'm using a 12v .14 A 80mm fan which now responds to fan speed settings below 100%.