Single fan madness pt 5 - Midfan File Server

IsaacKuo · Post by **IsaacKuo** » Sun Apr 30, 2006 7:32 pm

This is my file server, which also acts as my "power" workstation which I use for serious computing. It's not silent, because my main priority is keeping the three 3.5" drives cool and reliable. Also, I'm particularly sensitive to high pitched drive whine, and the low pitched hum of an undervolted 120mm fan helps mask the whine.

Components:

Sempron 3100+ and ECS nForce3 mobo - $80 (Fry's Outpost)

"Scythe" Coolink Bat1VS - $15 (NewEgg)

ePower LION semi-fanless PSU - $20 (MikeC's SPCR Clearance sale)

Radeon 9250 128meg - $38 (NewEgg)

512+256megs DDR333 - $???

Old Enlight mini-tower - $50 back in the day (CompUSA)

This baby won't win any beauty contests. It's just a squat beige box. Note that there are no significantly sized openings in the front. In its stock form, this case has a laughably puny intake area.

The rear view reveals modifications! The original PSU position was at the top-left-rear corner, making it impossible to fit a tower heatsink. I used a nibbler to cut out a new PSU mounting location at the bottom.

This new PSU location was inspired by one of BillyBuerger's cases. My airflow plan is pretty different, however...

Here, you can see the rear a little better. The PCI slots and the PSU at the bottom are the intakes. The ATX backplane and the original PSU mounting location are the exhausts.

Here's what the interior looks like. Airflow is controlled by two partitions. The middle partition along the AGP card forces the main airflow to follow a "U" shaped path--forward, then upward, then rearward.

The upper partition forces all airflow through the CPU heatsink.

Here's what it looks like with the partitions removed. Note the notches in the CPU heatsink for the fan clip. These notches are what holds the upper partition in place.

This is the main drive assembly, which includes the fan. This assembly rests on top of an upside-down mouse pad to isolate vibrations from the case.

This is the front view of the main drive assembly. As you can see, the "cage" is actually made out of 3.5"->5.25" adapter rails, mounted perpendicular to the drives rather than parallel.

This is the rear view of the main drive assembly. The 120mm fan is the Coolink fan which came with the Scythe/Cooling BAT1VS CPU cooler. It's mounted to the assembly with twisty-ties.

The case's only openings are to the rear, and the only moving parts are in the hard drive assembly deep within the front of the case. This helps cut down on the noise. The main airflow path is:

intake -> VGA, PSU, chipset -> fan -> hard drives -> CPU -> exhaust

Trunks · Post by **Trunks** » Sun Apr 30, 2006 9:08 pm

Impressive. I like the PSU movement very much. I still think paper ducts inside a PC are some kind of accident waiting to happen.

IsaacKuo · Post by **IsaacKuo** » Mon May 01, 2006 12:39 pm

Like in my other cases, it's cardstock--which is a thick sort of paper, I suppose.

If it's an accident waiting to happen, then it's not going to happen in this one--this machine runs much cooler than my Northwood and it even runs cooler than the 466mhz Celeron. This is partly because of the decent amount of airflow, and partly because the PSU is pretty efficient. With my priority on providing the hard drives plenty of cool air, the rest of the components benefit.

One other thing--these are "partitions" rather than "ducts". In my last three builds, I've used partitions rather than ducts. Before that, I used ducts. However, I'm increasingly of the opinion that particitions are better than ducts. Ducts tend to create dead zones of stagnant air.

Shobai · Post by **Shobai** » Mon May 01, 2006 7:33 pm

i'd have to agree with you there Isaac, partitions seem to me to be the better idea [as opposed to ducts]. you're circulating the entire volume [subject to fluid dynamics, i suppose] of the space you partition. however, as soon as you need the air to flow through something restrictive [ie, a heatsink] it will need to be ducted so the air doesn't take the least resistive path, around the side of the heatsink. how have you combatted the stagnation effects of ducts at the top of your case, for instance in front of the duct and behind it?

one other thing i notice: how do you stop the air moving out the front of the case, instead of passing through the heatsink duct?

in all, though, a very nice build! i'm going to be attempting something similar with a media computer i'm building in a custom case in the not too distant future..just waiting on a s478 motherboard.

IsaacKuo · Post by **IsaacKuo** » Tue May 02, 2006 1:48 am

Shobai wrote:however, as soon as you need the air to flow through something restrictive [ie, a heatsink] it will need to be ducted so the air doesn't take the least resistive path, around the side of the heatsink.

The way my style of partitioning works is that the CPU partition runs perpendicular to the airflow. Look at the upper partition. It runs across the CPU heatsink. It has a big rectangular hole where the CPU heatsink is. For the air to make it through this partition, it has to go through that hole.

This is a bit different from a duct, which is a tube that runs parallel to the airflow.

how have you combatted the stagnation effects of ducts at the top of your case, for instance in front of the duct and behind it?

In front of the CPU partition, there is nothing to speak of. The 5.25" drive cage is full of completely stagnant air, but this doesn't matter since there's nothing in them.

Behind the CPU partition, there's only about an inch of air above the CPU heatsink hole. Turbulent effects from the air flowing through the heatsink hole prevents any stagnation. In contrast, if I made a CPU duct then the air above the duct tube would indeed be stagnant.

one other thing i notice: how do you stop the air moving out the front of the case, instead of passing through the heatsink duct?

The case has no significant openings in the front. The stock front intake consists of a number of insignificant pinholes in the front of the bezel and a very small bottom intake.

in all, though, a very nice build! i'm going to be attempting something similar with a media computer i'm building in a custom case in the not too distant future..just waiting on a s478 motherboard.

Thanks! The basic "U-turn" airflow plan is good for an HTPC in an A/V cabinet because it doesn't require airflow to/from the front or sides.

Shobai · Post by **Shobai** » Tue May 02, 2006 2:27 pm

aha! i stuffed myself trying to think to deeply! larfs. i managed to confuse myself into thinking "airflow opening" == "duct". ah wells, you live and learn.

on a side note, what's the go with that cable that runsacross the top of your CPU partition, just below the heatsink, towards the bottom of the case?

IsaacKuo · Post by **IsaacKuo** » Tue May 02, 2006 8:09 pm

Shobai wrote:on a side note, what's the go with that cable that runsacross the top of your CPU partition, just below the heatsink, towards the bottom of the case?

It's the power cable for the motherboard. This motherboard has an inconvenient location for the power connector. Ideally, I should redo the partitions with a stiffer stronger material, along with a hole specifically for that power cable.

Shobai · Post by **Shobai** » Tue May 02, 2006 10:14 pm

is card stock the only partitioning you've used, or have you tried other stuff? do oyu use it mainly because it's on hand, or what?

i've got a whole bunch of 4" square foamcore sheets that i was given a while ago, but haven't found a use for yet. would these be suitable for partitioning? they're fairly sturdy, i'd just be worried about heat problems..whether they could cause the computer to catch alight. i really doubt they would though, just having a think about it now, because even if they were in contact with something that would/could get hot [of which there aren't many things, other than heatsinks, inside a normal case] they could be insulated with gaffer/duct tape.

hmm, the possibilities are endless..this is sounding more and more like a winner for my next build [looking to buy the motherboard on thursday/friday..then all systems go!]

IsaacKuo · Post by **IsaacKuo** » Wed May 03, 2006 4:10 am

Shobai wrote:is card stock the only partitioning you've used, or have you tried other stuff? do oyu use it mainly because it's on hand, or what?

I use cardstock only because I already had some and I'm lazy and I'm extremely CHEAP.

I've also used bits of currogated cardboard, which is a better material but slightly harder to work with (I'm lazy) and has even more of a ghetto look.

I now have a used piece of foamcore posterboard, and I'll be using that. It's a better material than either of the above, and doesn't have that ghetto look. I just need to get off my lazy butt and do it.

i've got a whole bunch of 4" square foamcore sheets that i was given a while ago, but haven't found a use for yet. would these be suitable for partitioning? they're fairly sturdy, i'd just be worried about heat problems..whether they could cause the computer to catch alight.

My first scratchbuilt case used a piece of foamcore as the base (not actually a partition), where it was in constant contact with the PSU's warmest side. There were never any effects at all. I doubt there's anything to worry about. Other SPCR'rs have used foamcore for partitions and ducts; I haven't heard of any issues with it.

Shobai · Post by **Shobai** » Wed May 03, 2006 4:04 pm

awesome! good to hear that you haven't had any problems with it. i'm ordering the motherboard for this new build of mine today, so hopefully i'll be able to start on it next weekend..will be using some foamcore for partitioning.

Le_Gritche · Post by **Le_Gritche** » Wed May 03, 2006 4:14 pm

Wow, a respectable looking case ! Where is the ghetto look of cardboard + marble vinyl tiles ? (Single fan madness pt 3))

That case may be a "squat beige box" but you are lucky the PSU fits width and height-wise. On mine it wouldn't fit (anyway I have no tool to cut the metal frame).

I have a question about the HDDs : they sit vertically rather than lying flat, is that because they wouldn't fit, or to ease the airflow turn-around, or for another reason ?
Aren't you worried about a potential reliabity issue, and does it change the sound they emits (seek noise particularly) ?

It seems there is no partition around the 120mm fan. Don't you fear some of the air just circulate back and forth around the fan, rather than following the more resistant path through the CPU HS ?