On 6/4/2010 8:26 AM, Invisible wrote:
> TC wrote:
>
>> However, I think that there is small functional difference between a
>> fan-blade and what is used in the impeller. It all boils down to
>> rotating structures pusing air molecules forward. I expected something
>> >new<.
>
> A fan pushes air forwards by using flat blades to fan it. An impeller
> pushes air *outwards* by centrifugal force. That's an entirely different
> mode of action. (Although of course impellers aren't exactly new either.)
>
> What _is_ new is that by using clever air currents, you can make the
> draft much bigger with less effort. And I guess it looks kinda neato.
>
>> And I really doubt that cleaning the impeller is easier than cleaning
>> a fan.
>
>  From what little I've seen, fans tend to get dusty when they're not in
> use, because they're exposed to the air. An impeller, by definition, is
> internal. When it's not running, there's very little air to get it dusty.
>
> Still, at the end of the day, if you don't like it, don't buy one. :-)


The reverse sides of the fan blades get dusty too, even when the fan is 
in use.

-- 
http://isometricland.com

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