[Misc] Exhaust fan noise

[niceville318]

Customers have recently complained about Sharp MX-4140's fan noise being louder than previous models. I noticed the LSU intake fan has a small aperture that the fan forces air into since it's quiet as hell when I pull it out. Has anyone else had complaints and/or discover any reasons for this?
Also, MX-2640's have a louder whining noise then the MX-2610's when the polygon motor is running. Anyone else come across this one?

[harleyrider]

Re: Exhaust fan noise

Haven't had complaints about the fans but the polygon motors are louder. Sharp had bearing style polygons then switched to air ride bearing style. The last training I was at they said they went back to bearings again.