psu fan

[SquallRealm]

hi everyone, i just got a fan controller and i am addicted to silence.. the only problem is my psu fan still makes some noice, is it possible connecting that thing to a fan controller and is it wise?

 

[FreiDOg]

sure it's possible. Open the PSU (insert all assoted waring about warranty and high voltage caps) and cut the fan's wires, add some extensions and a connector and plug it into the fan controller like any other.


[q]is it wise?[/q]

that's another story.
Lowering the fan speed will increase the PSU temp, and further detrate it's deliverable power.
I honeslty know nothing about your PSU, but the overclocked A64 and teh 6600GT are certainly not lightweights when it comes to power draw.

 

[SquallRealm]

tell me about it.... last night 6600 was telling me its not getting enough power.. wtf right?
I have to figure something out.. i have 2 options, either get silent fan or connect it to fan controller.

i was hoping on findind most silent of silent.. so far 21 dba which isn't so silent to my taste.

 

[Ice Czar]

and the hotter on average the PSU
(even if it is within its capacity to deliver the power reliably)
the shorter its lifespan
something that is typical of most fanless supplies
as a rule of thumb for every 10C increase (on average) life expectancy is halved
(conversely every 10C decrease its prolonged 100%)

arrhenius equation

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here is a great thread about ducting for a PSU
> http://forums.silentpcreview.com/viewtopic.php?t=8450
and some thermodynamics\aerodynamics infor

Lee Garbutt did a push>pull fan mod on a Turbo Cool 425
http://www.leesspace.com/quiet_psu.htm
maintaing the static pressure and airflow, but reducing the sound signiture
(strange when you consider he added a fan and replaced another to do that )


boning up on Fans might be helpful as well
its not just the airflow that is important, but the static pressure
a supply with a greater resistance will benefit from a higher static pressure



Air Flow Vs. Pressure Characteristics
Parallel & Series Operation
Stall of Axial Flow Fans

Basic Fan Laws
How to measure Airflow vs Pressure
How to Achieve Low Noise
Accoustic Noise
EMI
Introduction: Forced Convection Cooling
How to select the right fan or blower
Step 1: The Total Cooling Requirements
Step 2: Total System Resistance / System Characteristic Curve
Step 3: System Operating Point

here are three basic components to any thermal solution:
the heat transfer interface
(in this case the heatsinks total area)

the heat transfer medium's volume\pressure to time
(in this case airflow, with additional variables like airflow resistance)

and the temperature differential
(where using cooler air has a huge impact)
while the efficiency of a given supply at a given load will determine the high side of a temperature differential, by employing a cooler airstream you have the option to lower the lower side of the differential

a real good computer oriented guide to thermodynamics
General Heat Transfer Guide

Heat transfer is all about temperature differentials. Conduction through materials and convection away from surfaces is proportional to the temperature differential that exists. Basically the thermal resistance of a given solution changes with the temperature differential, which is why thermal solutions are rated in °C/W which leaves that variable ambient open but gives you a formula

The heat transfer through the wall follows a simple equation:
Q=k/L(T1-T2)

We can draw some interesting conclusions from this equation. First, heat transfer is proportional to the temperature difference on the object. If the temperature differential doubles, the heat transferred doubles. Second, the conduction coefficient "k" is proportional to heat transfer. If the conduction coefficient doubles, the heat transfer doubles Alternatively, for the same differential temperature, twice as much heat may be transferred. The final observation is "L". As thickness increases, heat transfer decreases. Alternatively, to maintain the same heat transfer through a material twice as thick requires twice the temperature differential.

while that addresses conductance, there is a corrallary for convection (transfer from the heatsink to a fluid (air\water\ect)
its known as Newton's Law of Cooling

your pretty much stuck with the heatsink a supply has, but altering the airflow isnt the only tool left to you
a few simple mods and that supply will increase its range, edit > or you can use less airflow and thus quiter fans for the same capacity\temperature
the main objective being not to draw the hot air from the heatsink through the supply and getting it its own cool airstream, you do of course still need to exhaust the case
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