What if you have 'too many' fans in the case?

Willy Higinbotham · Post by **Willy Higinbotham** » Sat Mar 17, 2007 4:16 am

Hello Everyone,

Well, I might be a little bit older than the average here and I'll be honest that I didn't open the case of a computer since the 486 era (yes, I'm that 'old

). But times are changing and I have more fun at tweaking and DIY'ing things than I used to do.

I'm planning my next computer and going through the parts list. I am doing my homework, I have downloaded the manuals of each component to make sure that everything will work.

It looks like I'll be having a total of 7 fans (5 case + 1 VGA + 1 CPU)

The motherboard will be an ASUS P5B Deluxe (no Wifi) and the PSU will be a Seasonic S12 500W.

All this stuff will be going in an Antec P182 case.

According to the motherboard manual, the P5B Deluxe has;

1x CPU Fan connector
3x Chassis Fan connector
1x Power Fan connector (I have no idea what a Power Fan connector is)

This makes a total of 5 connectors, where I'll be having 7 fans.

Now my questions are;

Where do I plug the remaining 2 fans?

Can all those fans be monitored? If yes, how?

Thank you.

andyb · Post by **andyb** » Sat Mar 17, 2007 5:39 am

Dude, this IS "Silent" PC Review - everyone here is trying to use as FEW fans as possible, WTF do you need 7 fans.???

The P182 comes with 3 fans, the PSU has 1, graphics card might have 1 and the CPU has 1 as well thats 6 total, and thats often 3 more than is needed.

I will use my PC as an example, it uses some pretty hot components, and just 4 fans, 1 of which (graphics card) spends most of its time off, so really I only have 3 fans, all of which push very little air and my PC is just fine.

The ideal P180/P182 setup is to remove the PSU/HDD section fan and seal off the vents around the PSU exhaust, the PSU fan will be fine for cooling 1-2 HDD's.

Buy a Scythe Ninja dont use the fan, and just use the top and back case fans, everything will be fine so long as you are using a modern CPU and not a Preshot.

There you have it, a 3 fan system - unless your graphics card REALLY needs one as well.

Andy

Willy Higinbotham · Post by **Willy Higinbotham** » Sat Mar 17, 2007 5:47 am

Hey, thanks for the reply.

Yes, I know that this is Silent PC here, maybe I'm trying to prove that with 7 fans you can still have a quite PC

Anyway, I was planning to go with the Thermalright Ultra-120 HSF, I know that it can be used passive as well, but I'll decide that after setting the system up.

Do you really think that the PSU fan will be enough to cool the HDDs? I might try that. (4 HDDs with in a RAID setup)

Thanks for the advice.

Aris · Post by **Aris** » Sat Mar 17, 2007 8:35 am

im down to 3 fans, all of which run at around 5v and are completely inaudible.

CPU fan
1x Case Exhaust Fan
PSU fan

PSU is completely seperated thermally from the rest of the case, so it always sits at the lowest voltage no matter how much i stress the system.

========================

Get a video card with a passive heatsink. A 7600gs or like the XFX 7950GT.

Get a case with a single 120mm exhaust fan. You dont need intake fans, as all they do is direct airflow over HD's. So unless you have 4 or 5HD's or running 10k rpm drivers or higher, you really dont need active cooling on them. Even if you do have that many drives, a single 120mm intake fan is plenty.

as far as your "what if i have too many fans" question. Some fans are powered by the device their on. Like video card fans, and psu fans.

Also, you can always hook fans up to molex connectors straight off the PSU, you dont have to plug them into the motherboard. I never use the motherboard connectors for fans.

Maelwys · Post by **Maelwys** » Sat Mar 17, 2007 10:40 am

I just built a PC around the P5B Deluxe, an Antec Solo, and a C2D E6600. Using a Scythe Ninja in passive, I have a grand total of 3 fans in the system. The power supply fan (Corsair 620) is nearly silent, and my video card fan (X1950 Pro) spends most of its time at 20% speed which is silent from 5 inches. The only actual case fan is a Nexus 120mm exhaust which is the only thing I can hear from where I sit @ 1 meter from the PC.

So I think you can easily get away with 1 or perhaps 2 case fans if you're worried about your hard drives. I'm running 2 drives with no active cooling and they run between 35 and 40C at load in 21C ambient.

J. Sparrow · Post by **J. Sparrow** » Tue Apr 03, 2007 4:28 pm

Maelwys wrote:The only actual case fan is a Nexus 120mm exhaust which is the only thing I can hear from where I sit @ 1 meter from the PC.

What's the point of having just one fan if you can hear it ?

better have two and run them both at lower speed.

IMO having many fans is OK as long as they're all inaudible.

Willy Higinbotham wrote:I'll be honest that I didn't open the case of a computer since the 486 era (yes, I'm that 'old )

they must be younger than I originally thought, I still have a 486 under my desk

jaganath · Post by **jaganath** » Tue Apr 03, 2007 6:09 pm

I still have a 486 under my desk

As what, a footstool?

peteamer · Post by **peteamer** » Tue Apr 03, 2007 10:52 pm

iamweasel · Post by **iamweasel** » Tue Apr 03, 2007 10:55 pm

I myself am running a total of 7 fans in my setup. I think if you select the fans carefully you can have a quiet setup.

My fans run at around 500-600 rpm AND the CPU and GPU are water cooled with an external radiator, so I probably wouldn't need all the fans. I do however like to keep things cool.

The fans are in a P180 (not the B version) in the following configuration:

The upper chamber: 3x Noctua NF-S12-1200; 1 at the front intake and 2 at the top and read exhausts.
The lower chamber: a Scythe S-Flex SFF21E in the center and a 80mm fan on an Antec Phantom 500 (replaced the stock fan on the Phantom with something quieter.) The PSU fan doesn't run though.

I also have mounted a fan into the "notorious" VGA duct to cool down the GPU memory... took a while to soft-mount and silence that thing... and I also have one quiet fan blowing directly at the chipset because I though it was getting too hot for comfort. Can't remember what the models of those fans are.

So, a total of 7 fans. I can only monitor 4 of 'em though. For example I run the exhaust fans from the same connector on the motherboard and only monitor the rpm of the one on the back. (I can see the one on the top anyway.) I think overall the setup is quiet AND well cooled.

I would however recommend replacing all the stock fans on just about anything you get. They hardly ever are "quiet".

Most quality fans come with an array of possible connection alternatives so although you cannot monitor all of your fans it should however be possible to run them... and with some creativity (and maybe some help from Zalman ;) you can control the rpm on them as well.

Good luck :)

J. Sparrow · Post by **J. Sparrow** » Wed Apr 04, 2007 5:41 am

jaganath wrote:As what, a footstool?

No good, not even for that

I don't have a use for it, but I don't feel like throwing it away.

Willy Higinbotham · Post by **Willy Higinbotham** » Wed Apr 04, 2007 8:16 am

How embarrasing, I almost forgot this thread!

I was 'busy' checking the archives here, there's so much to read and learn.

I have to admit that I felt the need to re-think my project after reading the forum archive. First of all, what I have learned is that, more fans does not always equal a cooler case. It looks like going with strategically placed fans is more efficient.

I also came to the conclusion that building air ducts around the heatsinks and certain components is crucial for getting the optimum results, both in terms of noise and cooling. I have decided to make the air ducts from liquid rubber. I will carve me the shape from wood which I'll use as a mold and pour the rubber on it, which will shape nicely.

Building a decent airflow in the enclosure is also important, so as I have posted on the VGA forum, I'm looking for the possibility to re-locate the VGA card by using a PCI-e extension cable and store the card away from the motherboard and maybe even putting it in a separate enclosure.

I'm still working on the project.

J. Sparrow · Post by **J. Sparrow** » Wed Apr 04, 2007 8:57 am

I have experimented a bit with ducts, but I feel a nicely laid out case with efficient heatsinks and proper airpaths can do perfectly without them (and sometimes even better than ducted - I tested cmthompson's solutions in my system and it's better left without)

IMO ducts are best used in two cases:

1) you have components that are completely outside the existing airpath
2) you need to create completely separate thermal zones (as in PSU ducting)

There's a drawback, too: they add up to the existing losses, reducing total airflow.

Sylph-DS · Post by **Sylph-DS** » Thu Apr 05, 2007 6:59 am

I'm newer than you, but if there's anything I've learned so far by reading a lot of SPCR's (and other websites) articles so far it's that quality beats quantity. The right fan in the right place, that's what its about.

When I first got my own PC I had 7 fans in it, "The more the merrier, I like cool systems.".... yeah. Now I have a cooler system than I had back then, with half the fans, and I still think it's a noisy bastard

andyb · Post by **andyb** » Thu Apr 05, 2007 7:26 am

If you have 4 HDD's I would suggest a slow running (5v) 120mm fan in the bottom compartment with all of the HDD's there, and remove the top HDD bay for optimum airflow for the rest of the components.

I found that when I had 4 HDD's in the bottom compartment of my P180 with my passive Phantom 500 PSU, the drives were getting quite hot as the single low pressure, low airflow fan could not cope with the extra heat and restricted airflow. It was however just fine with 2 drives.

Andy

J. Sparrow · Post by **J. Sparrow** » Thu Apr 05, 2007 7:30 am

I've never thought my answer could sound as advocating "quantity vs quality", much more like "there's no easy one-fits-all solution".

Erssa · Post by **Erssa** » Thu Apr 05, 2007 7:54 am

Ok, I have no empirical knowledge on the subject, but I figure 6 Nexus fans running at 5v are quieter then a single S12 power supply. It's one of the reasons why I opted to put another 12cm fan inside my case ~800rpms. Running them slower would make no sense to me, because S12 would still be dominant in noise, but I guess Nexus @ 5v has the same effect on silencers e-penis as a 600W psu has on a gamer.

IsaacKuo · Post by **IsaacKuo** » Thu Apr 05, 2007 10:14 am

Ducting can be used to reduce noise by eliminating fans without reducing airflow, but it's an advanced technique mostly suitable to low power systems which can afford to "reuse" air with airflow passing multiple components in serial.

The two most common sorts of ducts here on SPCR are:

1. The famous PSU duct that keeps the PSU fan from ramping up. This is mostly a crude kludge, rendered impractical by 120mm fan PSUs, and rendered moot by cases like the P180.

and

2. A CPU duct which allows eliminating either the rear case fan or the CPU fan. This is honestly useful, although it's shocking how many people leave both fans in place, rendering the duct pointless.

On my low power builds, I tend to use a CPU duct or partition in order to eliminate BOTH the CPU fan and the rear case fan. None of my systems have either a CPU fan or a rear case fan.

Sylph-DS · Post by **Sylph-DS** » Fri Apr 06, 2007 7:52 am

J. Sparrow wrote:I've never thought my answer could sound as advocating "quantity vs quality", much more like "there's no easy one-fits-all solution".

My apologies, my post wasn't directed towards you, but at the TS

BlueCan · Post by **BlueCan** » Mon Apr 09, 2007 7:23 am

IsaacKuo wrote:1. The famous PSU duct that keeps the PSU fan from ramping up. This is mostly a crude kludge, rendered impractical by 120mm fan PSUs, and rendered moot by cases like the P180.

"rendered moot"? LOL! The P180 is the "PSU Duct poster child". That would be what that "thermal zone" that's walled off by sheet metal which contains the PSU and some drives bottom of the case is--a great big PSU duct.

IsaacKuo wrote:2. A CPU duct which allows eliminating either the rear case fan or the CPU fan. This is honestly useful, although it's shocking how many people leave both fans in place, rendering the duct pointless.

This is how many OEM's build their "production" boxes--with the exhaust fan ducted to the CPU. The Thermalright HR01 comes with a duct for just this purpose.

-Patrick

J. Sparrow · Post by **J. Sparrow** » Mon Apr 09, 2007 3:44 pm

IsaacKuo wrote:but it's an advanced technique mostly suitable to low power systems which can afford to "reuse" air with airflow passing multiple components in serial.

It might be worth noting that in both the examples you made a duct is used to prevent hot air from being recycled

What if you have 'too many' fans in the case?

What if you have 'too many' fans in the case?

My 2c