On Mon, 9 Jan 1995, William R. Kennedy, NJIT CIAT, 201-596-5648@lenti.med.umn.edu wrote:

> Alistair Bell mentions that an inline fan can impede airflow if the fan is
> off.  On of the advantages of the JCWhitney fan for Vgons is that there is
> little of this effect.  The fan is centered in the duct, and the fan's
> housing is at least the diameter of the rest of the duct, and the air does
> not have to turn a corner as it would with a squirrel cage.  I wouldn't want
> to have to run the fan all the time, and I don't.  Not that a Vgon is quiet
> enough at 70+ so you'd NOTICE one extra fan.  
> B.
 
I didn't use a squirrel cage fan, but a "turbine" fan from a gas heater.
The air flow is straight through, and I guess the fan blade did freewheel
with the stock air flow, but I do beleive it impeded the flow. Don't get
me wrong, I think the inline blower is a great idea, I just didn't carry
it through to the end, ie. external mounting, insulation, proper rheostat
control. I still have the blower if anybody is interested.

Alistair