[Elecraft] KPA1500 fan noises

[Roy Koeppe]

"The benefit to putting fans in back blowing through the stock
screen/fans is that you get the slight added benefit of over-pressuring
the chassis which tends to keep the chassis interior cleaner. Assuming
adequate rear spacing, you can hide the fans a bit more...."

Yes. and the ultimate is placing them remotely in the closet with a clothes 
dryer hose leading to that plenum sitting at the back air intake coupling. 
Care must be taken so as not to ever restrict air intake to the internal 
fans when they're running at max speed.

Roy