>Rich says:
>
>>note -- High-pressure centrifugal blowers have relatively narrow, large
>>diameter squirrel-cages that operate at c. 3400 rpm.
>
>Unfortunately, they are also noisy. Quiet blowers producing lots of air flow
>have large wheels, go slowly, but don't necessarily work well under the back
>pressure requirements (I guess if it was big enough, it might be OK) - and
>Rich
>has highlighted the fact that you will have a lot of back pressure. The
>idea of
>a remote big blower is probably the best for quietness but it will need to be
>big to get over the losses in the duct work.
>
>Maybe amps with radiation cooled glass tubes and modest air flow requirements
>have advantages if you live at high altitude, although it's not something
>that
>I've ever had to consider.
>
The SB-220 uses a heavily-loaded impedance-protected motor. As altitude
increases, the fan blade turns faster due to decreased air density. I
would have no qualms about using a SB-220 at 10,000 ft. altitude -
provided the fan was oiled. .
>
>Peter G3RZP
>
>
>
>
- Rich..., 805.386.3734, www.vcnet.com/measures.
end
--
FAQ on WWW: http://www.contesting.com/ampsfaq.html
Submissions: amps@contesting.com
Administrative requests: amps-REQUEST@contesting.com
Problems: owner-amps@contesting.com
Search: http://www.contesting.com/km9p/search.htm
|