Address
Naaykens’
Luchttechnische
Apparatenbouw B.V.

Lovense Kanaaldijk 61
5013 BJ Tilburg
013 - 542 50 02

Noise

Foreign material in the fan housing
This could be anything from a loosened bolt to somebody's lunch bag. Inspect the wheel and inside of fan housing and clean thoroughly.

Squealing V-belts
Belts are either loose or misaligned. If belts show wear, you are better off to replace them now and avoid a future breakdown.

Worn ball or roller bearings (howling, screeching or clicking)
Change the bearings immediately before they cause additional damage. Failing bearings tend to wear the shaft, so you want to be absolutely certain the shaft is full size before installing these new bearings. "Mike" the shaft both under the bearing and next to it and compare the two readings. If they do not match, replace the shaft. New bearings installed on a worn shaft will not last long.

Bearing seal misaligned (high pitch squeal)
Realign the face of the bearing so that it is perpendicular to the shaft.

If the fan housing has a metal shaft seal, it could be misaligned and rubbing on the shaft
Loosen seal plate bolts, recenter the seal on the fan shaft and tighten the bolts. If the seal is fiberglass, cork or rubber, be sure the metal backing plate does not touch the shaft.