<VV>Mo Fan

[JVHRoberts at aol.com]

Actually, when you block the output of a vacuum cleaner, the motor speeds  up 
also. Loss of flow unloads the blower, and a Corvair fan is no different. The 
 reason the tank heats up when the outlet is blocked is there's a bypass port 
to  protect the motor, and its recirculating air into the tank. 
 
 
In a message dated 7/14/2005 11:51:16 A.M. Eastern Standard Time,  
pp2 at 6007.us writes:

>  I know the fan HP is modulated by the  damper  doors,

Actually, blocking the output makes the fan loss go up not down  and 
increases residual heat. Anyone with an old tanl vaccuum can see -  block 
the input and the rpm (inverse of load) goes up and the tank cools.  Block 
the output and the rpm goes down and the tank gets hot. Is why an  efficient 
turbo has the throttle plate on the input side. It also reduces  turbo lag 
since the wheel is already up to speed but that is a whole  'nother issue.

Suppose that since the doors are to warm up and the  increased plenium 
pressure is good for heat, this is not a bad thing, just  the hp required 
with a blocked output goes up not  down.

Padgett