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On Mon, 20 Dec 2004 03:59:17 GMT, igor wrote:

On Sun, 19 Dec 2004 21:02:18 -0500, wrote:

Motors driving fans work less when the
airflow is cut off, and conversely, are at risk of overload when the
airflow is too high.

Talk about counterintuitive. Hmmmm? So, if I take a house vacuum, run
it,
and put my hand over the end for 30 minutes, the motor hardly works, but
if
I hook up the outlet of my shopvac to blow into the vacuum's hose the
motor
has to work very hard and will overload? Sorry, but I don't get that. --
Igor


house vacs are different. leave them blocked and they'll overheat.

That is because most of them use the air being drawn in to cool them and
when you block it, they overheat.