Many fan issues found show how costly improper cleanings can be in addition to grease fires. This fan was recently cleaned and they were having vibration problems. Rarely do I find the discharge (Backside) of the fan blades properly cleaned. As little as a once of misplaced grease or dirt can through the fan out of balance causing not only noise issues, but also premature wear and tear. In some cases, the vibration can simply blow the fan up into pieces or short the wiring out. Also, it causes the bolts holding together the fan to wear through the aluminum housing which can also cause the fan to fall apart. Fan bearings also take an extreme stress when there is excessive vibration. We run into issues where we make more money repairing fans that are improperly cleaned than we would have if we actually cleaned the fans and exhaust systems ourselves. When choosing KEC vendors for price alone, one must keep in mind the hidden areas like the back of the fan blades that are often either completely missed or only partially cleaned. Newer NFPA96 standards do call for installing access to reach this area, but the cleaning company with the right equipment can and must clean it with or without this extra access. A simple inexpensive 45-90 degree angle on the end of a pressure washer lance can easily reach most of these areas. A digital camera can take a picture to verify cleanliness. In extreme cases, this vibration can even cause a grease fire when the bearings fail, the blades fall apart, or the wiring becomes compromised. The pictures below show the fan already falling apart with duct tape covering the worn out holes. The next two pictures show how the fan blades were left. Next we look down the vertical riser and see that this area was cleaned, but we drop a camera down and view the horizontal duct past what we can see from above and see years of buildup. This is a wood structured building that this amount of grease most likely will cause catastrophic loss when this grease catches fire. Remember that only about 1/16" of grease buildup can sustain a 1750 degree F. fire for more than 5 minutes.
Originally published July 5, 2013 on Tales of the Greaser.