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Re: [APD] Canopy Cooling



So long as the voltage is correct and the transformer can
handle the amount of current that the fan needs (and the
fan blades are unobstructed), the fan will draw only the
amount of current it should. If you obstruct the fan,
slowing its rpms, it's impedance will fall and that will
increase the amount of current it draws, but these fans
should never be operated with anything rubbing on the
blades.

A problem with really cheap wall warts is that, under load,
they are not necessarily providing the voltage for which
they are rated. If the voltage is high, you can drop the
voltage with a small resistor, or get a better wart, or use
an AC fan. They are just diff choices. But you don't need a
really fancy transformer just to run one or two or four of
these little fans. A switching transformer would be, imo,
tremendous overkill.

I urge doing a bit of research before investing in the fans
you mentioned. At a minimum, consider this:

http://fins.actwin.com/aquatic-plants/month.200412/msg00261.html

The design is not terribly unconvetional -- they seem, in
fact to be rebranded fans. But the performance cited is
truly exceptional, imo, even when cdompared to the original
brand.

Good luck, good fun,
Scott H.
--- Jerry Baker <jerry at bakerweb_biz> wrote:

>> 
> Wall warts are not that cheap. Unless you can find one
> that is rated for 
> the exact current of your fan, you have to get a
> regulated - or 
> switching - transformer. Those aren't so cheap. I can
> find them at 
> surplus places for a few bucks, but it doesn't look like
> there is a 
> reliable source of them for under about $15 each.
> 
> I was looking at using 120mm Panaflos. Being a computer
> nerd, I am 
> already aware of the quest for silent PCs. There is
> another company 
> called SilenX that makes 120mm fans rated at 11dBA and
> 14dBA with air 
> flow rated at 40 CFM and 58 CFM respectively. They also
> have an MTBF of 
> 100,000 hours. Two of those would be more than adequate
> for just about 
> any canopy. You would be hard pressed to hear 14dBA over
> all the noise 
> your fish make while swimming around.
> 
> 
> -- 
> Jerry Baker
> _______________________________________________
> Aquatic-Plants mailing list
> Aquatic-Plants at actwin_com
> http://www.actwin.com/mailman/listinfo/aquatic-plants
> 


* * * * * * * * * * *
The September 15 deadline for entries to 
the AGA Inernational Aquascaping Contest is fast approaching.  

Don't forget to indicate if you want your AGA entry to also be an ADA (Aqua Design Amano) Layout Contest entry!

All the info is here: 
http://showcase.aquatic-gardeners.org

Share the fun and show your work!
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