Fans are installed in the box 
a) In this connection, you'd better think about exchange bearings expediently and don't take down the fan try your best.
b) Set up window or door for inspecting and exchanging bearings.
For more information or enquiry, please contact Environmech Sdn. Bhd.
Contact us: http://www.environmech.com/p/contact-us.html
Website: www.Environmech.com
