Solved Not enough cables for fans?

Nvidia / Awrdacpi
April 20, 2014 at 04:21:56
Specs: Windows 7, 2.1Ghz
I'm planning to buy case fans for my old computer... 1 fan on the back to put air inside and 2 exhaust fans on the side... But I only have 1 problem.. There's no more cables from the psu to put to the fans... I was wondering how can I put power to the fans?.. Is there like a splitter or something?
Thanks!

I'm tired of a freaking piece of crap pc o.O


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✔ Best Answer
April 21, 2014 at 05:16:55
That is all that is need is a small hole in the front. The means of getting air in at the front is probably a lot bigger than you realize as any old gap will do and cases are not made airtight. The quicker the rear fan can exhaust the air, the quicker the air will enter at the front, otherwise you would end up with a partial vacuum in the case and you would need a huge fan to do that.

A smaller hole can be beneficial as it will set up a venturi effect. (google it) This has the effect of cooling the air as it enters the case, a very desirable effect.

Bear in mind that as the air in the case heats up. Hot air expands and rises so it will find its way to the top of the case naturally. You need a bigger exhaust hole because you are exhausting a greater volume of air than is coming in the front.

I would forget about fans on the side of the case, certainly not one taking air in and the other taking air out. That will just disrupt the air flow within the case and possible cause hot spots of stagnant air.

Stuart

message edited by StuartS



#1
April 20, 2014 at 06:08:26
Yes you can get molex splitters. You might want to consider further your airflow plan for the case. It would be unusual to put an intake fan on the back. Usually the hot air is exhausted from top/rear with intake low-front or side. Commonly there is a cooling fan built into the power supply and it exhausts to the rear. It would not be logical to place an intake fan adjacent to that exhaust.

Goin' Fishin' (Some day)


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#2
April 20, 2014 at 06:17:38
Many motherboards have connectors for case fans. These are often designed to alter the fan speed depending on the temp. Check your MoBo manual.

Nigel

Wind slow


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#3
April 20, 2014 at 07:43:23
My PSU has it's fan on the back not inside.. There's no other fan holes in my case, there's only 1 on the back and 2 on the side... Any suggestions about the airflow?

I'm tired of a freaking piece of crap pc o.O


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Related Solutions

#4
April 20, 2014 at 07:48:10
"1 fan on the back to put air inside and 2 exhaust fans on the side"

Wrong! All you're trying to do is purge & replace the air in a small box that's approx. 1.5CF in volume. Check the CFM rating of the average 120mm fan (which is what you should be installing) - generally around 60CFM±. That means the air in the case would be completely replaced 40 times per minute. A single 120mm exhaust fan in the rear is all that's needed for good case cooling. The following article is a little dated but have a look:

http://icrontic.com/article/pc_airf...

"A single rear exhaust fan produces the best results overall. This flushes the theory of more is better right out the door"

message edited by riider


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#5
April 20, 2014 at 08:09:00
Ohh... So placing an exhaust fan on the back will be better right?.. Thank you.

I'm tired of a freaking piece of crap pc o.O


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#6
April 20, 2014 at 10:23:58
Air flow should be in from the front and out through the back. If you have an exhaust fan in the back the air has no choice but to come in through the front.

If the case has side fans I'm not sure which direction is best. It might depend on how open the front is. If air intake is good from the front then maybe side fans should blow out. It not then maybe they should blow in.


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#7
April 20, 2014 at 10:54:14
IMO side fans do nothing more than disrupt clean air flow from front to rear. Most cases have a loose fitting front bezel. There is plenty of opportunity for air to enter from the front. Remember, when you have both the power supply and another rear discharge case fan installed those fans create a partial vacuum. using side fans will allow the required air to enter from the side. This can result in the drives mounted in the front and possibly the RAM, to overheat from lack of circulation.

While we are on the subject, power supplies work best at removing heated air when top mounted in the case. Bottom mounted power supplies should be avoided, IMO.


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#8
April 21, 2014 at 04:45:19
There is actually no hole for the air to enter from the front, only a small hole on the bottom front... So maybe placing 1 intake fan and 1 exhaust fan on the side would be better right? And 1 exhaust fan on the back?

Or any suggestions to where I can place these fans?

I'm tired of a freaking piece of crap pc o.O


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#9
April 21, 2014 at 05:16:55
✔ Best Answer
That is all that is need is a small hole in the front. The means of getting air in at the front is probably a lot bigger than you realize as any old gap will do and cases are not made airtight. The quicker the rear fan can exhaust the air, the quicker the air will enter at the front, otherwise you would end up with a partial vacuum in the case and you would need a huge fan to do that.

A smaller hole can be beneficial as it will set up a venturi effect. (google it) This has the effect of cooling the air as it enters the case, a very desirable effect.

Bear in mind that as the air in the case heats up. Hot air expands and rises so it will find its way to the top of the case naturally. You need a bigger exhaust hole because you are exhausting a greater volume of air than is coming in the front.

I would forget about fans on the side of the case, certainly not one taking air in and the other taking air out. That will just disrupt the air flow within the case and possible cause hot spots of stagnant air.

Stuart

message edited by StuartS


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#10
April 21, 2014 at 18:00:32
Okay I get it! :) Thanks!

I'm tired of a freaking piece of crap pc o.O


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