[PLUG-TALK] Another use for 12 volt fans?

[Keith Lofstrom]

On Wed, Sep 20, 2017 at 10:08:40PM -0700, John Jason Jordan wrote:
> 1) I asked my friend Mr. Google about sound levels for computer fans
> and came up with Noctua as offering the quietest fans. Does anyone have
> experience with the Noctua fans or alternatives?

I've used Noctua fans, they are indeed very quiet ... and
much more spendy than the cheap Asian fans.  Worth it.

> 2) What about power supplies? I don't need a lot of current for my
> plans. Are there very small power supplies (preferably without fans)
> that would provide enough current for half a dozen four inch fans?

I use these power supplies for deploying LED strip lights.
At full load (hot), they don't last as long as half load.

If 3 or 5 amps will do it, I have a couple of cheap Asian
power supplies (via Amazon) that will work.  The problem
with these is that they are decently designed but poorly
assembled; before you install one, I want to disassemble
it and correct soldering mistakes so it doesn't fail
when hot. 

If the fans stop, will that cause BAD THINGS to happen
with the setup you plan?

BTW, you want to push room air INTO the fire with the
computer fans, not pull heat off it.  Plastic fans and
precision bearings won't survive long when hot.  These
fans typically blow room air INTO a computer (especially
through the power supply), not suck hot air out.  You can
use one of the fans to push heat past the little 12V power
supply and into the fire.  USE the heat the power supply
makes, and keep it cooler so it lasts longer.

The power grid is overloaded and flaky; consider a battery
to keep the fans and fire going when the power goes out.

Lastly, big slow fans are much quieter than small fast
fans for the same amount of air flow.  IIRC, double radius
at 1/4 the RPM moves the same air with 1/16 of the noise.

Keith

-- 
Keith Lofstrom          keithl at keithl.com