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Re: Cooling Fans



CFM stands for "cubic feet per minute".  It tells you what air flow rate
the fan is capable of, with unrestricted airflow.  For a 3db change, the
power is doubled(or halved).  Those levels are not that high so I don't
think you would notice unless you placed them side by side.  The current is
probably electrical; it should be specifies an A or amp or ampere or may be
ma.  I would recommend looking for a surplus electronic/computer hardware
store.  Computer power supplies use the fans and are sometimes equipped
with a seperate guard.  I have a couple of 4" ones on a water cooler in
back of the aquarium.  I don't have guards on them but they are out of the
way.  Hope this helps.

Regards,
Onis
k5vkq at ix_netcom.com
>
>Thanks to everyone who e-mailed me. My hood is only 2" tall so I have to go
>with a 12/24vdc fan (ac fans are at least 2.5" square). I've visited a couple
>of mail order electronics pages and I'm having some trouble with the
technical
>aspects of choosing a fan. First of all, what does "C. F. M." stand for and
>what are its implications. Second, is there a noticable difference between 27
>dB and 33 dB. Third, does "current" refer to electric current or to wind
>current produced by the fan. Fourth, either "they" don't make fan guards for
>fans smaller than 2"x2" or the mail order houses have decided it isn't
>profitable to sell them and, as such, don't. Does anyone know where I can get
>small fan guards and are they really necessary for safety's sake? Lastly does
>anyone have any particular preferences among teeny tiny fans. Thanks a bunch
>to everyone.
>