One must be very careful cleaning direct drive up blast fans. See attached picture looking behind the fan blades showing is how the motor is installed and how open it is to pressure washing when cleaning exhaust fans. As you can see, the motor is flush to the fan housing facing the fan blades. There is virtually no way to protect the motor on these style fans other than attempting to wrap the top of the fan blades to prevent over spray. Unfortunately, this is not only extremely difficult and actually does not work well, but it leads to grease buildup on top of the fan blades and vibration issues behind there one attempts to seal up the fan. The best solution so far is to attempt to get an enclosed motor installed where possible. another issue is repair of these fans is also more difficult that Belt driven fans as the fan blades need to be removed in order to replace the motor. Many customer opt to replace entire fan each time which leads to other issues. I highly recommend only installing belted fans. Plus, make sure the seals to the motor housing on the up blast fans are kept in good condition. I will touch on this more in a future blog or article.
Originally published June 11, 2014 on Tales of the Greaser.