I'm building an air channel for the psu - Enermax EG-365P-VE(FMA). The channel itself as well as sound absorbing walls have already been done quite easily thanks to the guides and suggestions made in this forum.

I'd like to get your advise on 2 things I found on my set up though,

1. The exhaust air that come out from psu would feel warm only on the top portion of the fan, air from the bottom portion is noticably cooler. Obviously due to the fact that all psu components are on the top. I guess my question is whether there's a better way to make use of this cooler air e.g. build a 'ramp' on the bottom part where intake psu fan used to be to force air to go up and mix with warmer air thus reducing overall temp - or this 'ramp' idea is a wishful thinking and would simply restrict the airflow and does not work.

2. The reason I'd like to do #1 is because the thermistor on my psu is located very closed on the pcb near the coils and was previously cooled by the intake fan. With the psu channel, cold air will not touch this thermistor any more as it's blocked by other components - as a result the exhaust fan always been ramped up to 2250 rpm regardless of manual setting at lowest. The thermistor is fully covered with some white stuff - look like lots of glue - so relocate thermistor is not going to be easy.

Alternatively, if #1 is not the way to go, may be I could connect the exhaust fan directly to MB and probably move the fan inside the channel.

Any suggestions?

Edit: Updated subject line

The ramp sounds like a 2-minute build with a piece of cardboard and some tape. I haven't heard of anyone having this problem/idea before, so why don't you just go ahead and build the ramp and test it? You can be our guinea pig Be sure to monitor those temps though! You never know what could happen.

ecto, thanks for promoting me to guinea pig status Yeah, it's a 2 minute mod piece except that it'll take 30 minutes just to disemble the channel, take the psu out, and then put everything back again, test the mod out,...etc. and it's likely to be repeated a few times with different shape and angle of the 'ramp'. I thought I could avoid that by posting the idea here and someone would say it has been tried and didn't work.

Kidding aside, I probably will try it out this weekend. I think I'll remove the psu exhaust fan and move it inside the channel just before the psu because I think the air will have a stronger flow being pushed rather than being pulled. Will have to cut open the whole inside grill of psu as well to clear the path.

Anyway, this test will just for my own curiosity now since moving exhaust fan to inside and connect it directly with MB/4 pins molex makes the thermistor issue a moot point as it no longer has any effect on fan speed.

For the record, during typing here, air from top part of exhaust fan shows +6C over room temp and air from bottom part (using same temp probe) is only 1.5C over room temp. This being measured with front bays totally open.

Oh. You should have a case where the top can be removed for easy access to the channel I'll have to think about that once I get around to building my own PSU channel since the top of Lian-Li's PC-60 can't be removed

About the placement of the fan, won't the direction of the airflow become somewhat "jiggly" if you put the fan before the PSU? Isn't it so that many PSU fans are placed so they draw air over the heatsinks in the PSU? What I mean is if you push air over the heatsinks it might turn to the sides, hit other parts in the PSU etc, and the airflow path over the heatsinks will be worse, effectively making the PSU run hotter. I'm just guessing here.. I bet there's people here who have tried this and can comment further on it.

I got curious and took temp measurements at the exhaust of my PSU. My temps (Zalman 400B) is 8.5C over ambient at top part of exhaust, and 8.3-8.7 (hard to get stable reading) at bottom part of exhaust, so luckily I'm not experiencing your "problem". These readings are with my case open and the machine practically idling - I don't even want to think about temps with the side on.. that's why I'm gonna need a PSU channel too

But you should try re-positioning the fan. No PSU is like the other, it might work like a charm!

ecto, you can try it now. It's not that difficult. My case is Lian Li PC7 which basically is very similar to yours except that you have a sliding MB tray - mine is fixed. The Lian Li case already has 3 sides of the air channel made for you, you only need to put the bottom part.

I don't think there'll be negative cooling effect for moving exhaust fan inside since the heatsink for my Enermax is put along the same line as air path if heatsink is cutting across air path then there may be some issue. To the contrary, it should help as I read somewhere in this forum that air will flow in a vortex-liked cone shape when moving out of fan but will flow in a straight line on the sucking in side. Anyway, we're talking low rpm here so it doesn't matter much.

Only negative effect I can think of is that I'll be moving the noise source i.e. fan closer to front thus making sound blocking more challenging but we will see. I'll use the 92 mm fan that used to be psu intake fan and put it on fanmate minimum or put it on 5V line if it start reliably, though I doubt it. I'll not have rpm reading with this fan though

The only thing that took me so long in making this channel is to find material for front bay cover that will go along with the rest of case (Lian Li standard brushed aluminium color). Finally, I settled with perforated steel sheet and painted it with anodized silver look alike. I'll add some blue LED inside the channel to make front bay looks less dull. If you case is black, then it's easy just buy some cheap replacement cover for car speakers - and you're ready to go. The grill looks like it would restrict air intake, but surprisingly it doesn't have any effect probably due to the fact that I use 2 top bays for intake.

Edit: Typos, and adding response on psu heatsink.

I'm gonna make some more temp measurements then build a very simple air channel with the help of a piece of cardboard.. shouldn't take more than a couple of minutes once I get to it.

My case isn't black. How did you attach the perforated steel sheet? To the case itself, or did you cut up the bay covers? Any pictures?

Just folded the steel sheet on all four sides and put it in the 2 front bays. Make good measurement though and make sure that once folded the 'steel cage' can pass the front bezel with barely touching the bazel on the side. If you want you can secure the cage with front bay using screws, my cage basically sits on top of my CD Rom with just enough pressure from all sides - no screw at all. Did I mention make good measurement.

Will try to get picture as soon as I have time.

Thanks for the info ultraboy. I'll see what I'll use. I haven't really decided whether to separate the PSU from the rest of the system or not.

I "built" the PSU channel yesterday - I say "built" because, like you say, with the Lian-Li PC60/70 you have three sides "for free". All I needed to do was cut a piece of cardboard. It literally only took a couple of minutes :)

I have my CDROM drive in the second bay from the top, so I removed the top bay cover and slid the cardboard in place and secured it with some tape, so it extends from the back of the CDROM drive to the bottom of the PSU. The cardboard piece is not in a very steep angle, and the openings in the back of my Zalman 400A-APF are pretty big so I can say airflow is pretty much as inunterrupted as it can get from the front to the back.

Some temps (first number is PSU exhaust temp in degrees C over ambient):

Without duct:
idle: +11,0/cpu 46
cpuburn: +14,0/cpu 57/mb 37
cpuburn+doom3: +15,2/cpu 59/mb 41

With duct:
idle: +6,3/cpu 45/mb 34
cpuburn: +8,5/cpu 57/mb 37

As you can see, I got quite a nice temperature drop with the channel, without affecting CPU temperature! This most likely depends on the fact that I also have an 80mm exhaust fan right next to the CPU, running at 12V...

As I mentioned in the first paragraph I'm not really sure what to do. One thing that's for certain is that I'm going to remove the exhaust fan next to the CPU - it's simply too loud. If I then decide to use the PSU channel and duct fresh air in from the back to the CPU, there won't be anywhere for the hot air from the CPU to go.

What I'm thinking now is that I'll use the PSU channel, and duct fresh air from the bottom front (there's already two fans there so why not use them) to the CPU, ducting the hot air from the CPU out the back of the case. This means I'm gonna have to turn the fan on my Zalman 7000Cu upside down to blow upwards, or remove it completely and just use a fan attached to the back of the case to suck air through the heatsink a´la SpyderCat's technique.

Any suggestions/comments, anyone?

ecto, I'd like to offer the following comments based on my own experiences

1. Your temp drop on psu air exhaust looked respectable, mine didn't drop that much. But may be because I ran my psu fan at 40%. You may recall my earlier grumble about thermistor in psu, finally I decided to keep psu fan where it was and got myself a pwm fan control which gave me another challenge I posted here. Anyway, what I want to say here is that with the temp sensor now wedged between psu heatsink I can adjust psu fan accordingly (if I can get the fan control unit to work more reliably - i'm getting there I think ).

2. May be other people reading this can give a more authoritative answer, but somehow I think cpuburn will not load psu to the extreme. I normally use the 'Nature scene' in 3dmark to load psu - I learn this by accident since my old UPS always beep like crazy everytime 3dmark come to this scene. That beep never happened when I ran 2 sessions of cpuburn together (since my cpu is a HT so it need 2 session to load cpu to 100%).

3. As for the case exhaust fan - have you already cut out the grill? If not this will be the first thing I recommend. It helps tremendously. I've done even further - I also cut out most of front filter cage leaving just about enough at the rim of the cage to hold filter in place, then took out the 2 front intake fans and installed a 120 mm fan as exhaust fan. This 120 mm is installed outside the case using 80->120 fan adapter since the hole is for 80 mm fan size. Prior to buiding psu air channel, I was able run this 120 mm fan at fanmate minimum (around 900+ rpm) and the system was pretty cool with low noise. This is now becoming my standard case set up for airflow/temp/noise ratio. I just built another system for my son based on this - worked like a charm

4. With psu air channel, while psu temp is stable and lower noise as I have one fan less - I found that my MB temp and Hdd temp (through SMART) increased by about 3-5 C even when I ran my 120 mm fan at fanmate max. I was confused at first but then realized that before psu air channel I was running a negative pressure case with 3 fans pulling air out (case and 2 psu fans) and only 1 fan now doing the job - the amount of airflow in the case is therefore lower -> temp increased. I do not worry about MB temp increase but Hdd temp increase makes me nervous. Btw, the 'higher' Hdd temp I'm talking here is only 39C at normal use (max. temp recommended by Seagate is 60C) so it's nothing serious - just my own peace of mind issue. I'm still working on this one - probably Bluefront's Birdhouse duct

A bit long post, but hopefully will give you some idea on your system.

I thought of running 3DMark at the same time as running CPUBurn, but I didn't have it and since I just moved I'm wating for my ADSL to be installed - right now I'm on 56k.. Impossible do download it on 56k I kicked some Doom 3 butt instead, while running CPUBurn.

But I'm pretty pleased with my PSU temps - I'm sure I can go 10C higher without any problem whatsoever - the highest temp I recorded under load was 33C.

Since all my other fans are so loud I can't judge the loudness of the PSU fan, or if it's thermal sensor works as it should (ramp up with increasing temp). Maybe I should unplug all my other fans and test? I wish I had a PSU loader like MikeC :/

Anyway, that's not very important now. I'll get to the loudness of that fan after I've dealt with all the others Then I'll decide whether to use a PWM control or just set the PSU fan to a static 5 or 7 volts.

I haven't cut anything in this case yet, but I'm about to - just have to decide which silencing/ducting path I will take I visited a friend who works at a company selling stuff for ventilation/building - very handy to have a friend there He gave me a whole bunch of ventilation tubes and adaptors to play around with.

So no I have two meters of bendable aluminium tubes, 80 and 100 mm in diameter, and 12 meters of plastic tubes (metal circles with plastic around, oftens used in kitchen ventilation) which are 82 and 102 mm in diameter. I also got some adaptors which attach at the end of the tubes - this will hopefully make attaching them to the case easy. One of them should also fit over my Zalman 7000Cu. I'll see which ones I'll be using - the aluminium tubes are good because when you bend them, they stay that way. The plastic ones are good also as they are extremely easy to work with.

With all this tubing I got an idea. At first my plan was to suspend my two hard drives in the cage behind the front fans, but now I'm thinking I'll put both drives in a vertical position right next to each other, at the side of the cage closest to the opening side panel. This would leave space in the cage for uninterrupted airflow from one of the front fans, and with a tube from there and all the way up to the RAM/NB/CPU area - voilá - fresh air directly from the outside to the hottest parts in the computer. This would then be exhausted with an exhaust duct from the CPU to the back of the case.

I think this idea could work out pretty well since the CPU/NB/RAM area won't have to deal with hot air from the graphics card - especially if I use a VGA silencer with an intake duct from the PCI back cover beneath the Silencer exhaust.

Another thing in common, mine is version A though.



Sounds very complicate to me. May be I do not fully understand your plan, but wouldn't this set up somewhat block intake air from cooling your Hdds.

Heh, mine is version A too - I just don't point it out as the only difference (if I recall correctly) between the A and non-A versions are that the A version is compatible with both Intel and AMD. Never mind. =)

It seems I've steered this thread a bit out of topic - I'll start a new thread in The Silent Front about my ducting plans.

Back to the PSU ducting.. I've taken a couple of pictures for the interested:

From below:


From front:


It's quite ghetto, I know. I'll fix it more nicely once I decide how to set up the rest of the system. I also need to cut a hole towards the right side in the last picture, as there is nowhere to stuff away excess PSU cables (behind PSU/mb) in a PC-60. This is because of the slidable motherboard tray.

My PSU air duct is now finished. You can see 10 photos here.

The photos aren't visible to me - I think the world doesn't have permissions to see them.

As noted somewhere else, http://www.imageshack.us/ is great, and free, for image hosting, and will even do thumbnails so you could insert just the thumbnails in the post.

Same here - no pics

Terribly sorry. All pics should be viewable now.

Nice work ultraboy. I _really_ like the front bay grill you've made. Looks professional and classy!

ecto,

Thanks for the compliment.

Add 2 cheapo thermometers on a new front grill of psu duct.

Each is connected to a NTC thermistor salvaged from my Zephyrus pwm automatic fan control that I've been trying for the last few weeks to make it work - and finally decided that enough is enough

Thermistor on the left is attached to the back of R9800SE@Pro underneath ZM80D, another thermistor is in between psu heatsink. So now I can adjust fan speed based on these temp info.

The manual fan control in picture is Noise Isolator which happen to be a pwm too.

ultraboy.....I've followed your little duct project with intrest, since I've spent the last three years trying all sorts of duct-setups. Your final photo of the front of the computer looks really nice (although you might get some harassment for the lights). I do like the visible full-time digital temp readouts. Makes judgements of what's happening easier.

Ok here's the negatives.

You've constructed a somewhat complicated intake duct setup that serves only to bring ambient air to the PSU. It cost you the upper two bays and at the same time opened up the front of the computer for noise leaks, despite your dampening foam. Wouldn't there have been an easier way to keep the PSU fan noise down? Like maybe a different PSU, maybe a PSU fan mod?

You are now faced with another problem...namely getting the rest of the computer quiet, and finding a quiet way to exhaust internal case heat now that the PSU is out of the picture for that duty.

IMHO...get rid of that HSF. Almost impossible to duct properly, while serving to just blow hot air around in the case. Looks like you'll need at least four fans in your setup, if you want cool hard drives. Don't take offence....this is just constructive critism.

Very interesting, I think this would work very well for cooling suspended hard drives, or at least that's the only decent way of cooling drives in the 5" bays I can think of; an 8 to 12cm fan adapter on the PSU would work well for that, weird coincidence that you're using one for your case fan.

Bluefront, no offense taken whatsoever - in fact I'm grateful for criticism, otherwise there would be no improvement

I agree that taking 2 front bays for air duct is a waste, and in fact I was in the process to reduce it to 1 bay (btw, I've already tested it by covering up 2/3 of the intake, that increases psu temp by only 1c) - then I thought why not adding the 2 temp reading instead since I have no plan to use the bay anyway. Agree also with the blue light - but without it the intake would look very boring and kind of out of place. At one point I even planned to put in a UV light, and put some UV sensitive toys in it - but my 5 year old son did not agree to let me 'borrow' it.

For internal case heat - you are right that heat has increased with psu duct due to less airflow. That's why I have to add the 2nd 120 mm fan behind hdds as you can see here. Both 120 mm fans plus Z7000A are all run at minimum setting - while not quiet but low enough to be overwhelmed by ambient noises. I would hear these fans late at night (about 11 p.m.) though. I was thinking about copying your birdhouse duct, but not too sure about my lousy workmanship

My main problem in trying to achieve quietness is due to the fact that I have no easy access to good quiet fan here. The 'best' is Stealth (and only 80 mm size) - so you can imagine what kind of fan I have to centend with. Same applied to good/quiet psu. Probably will have to mail order Globe fan from MNPCTech.

So...the challenge continue...

What an excellent idea mathias I should think about that seriously, may be put one of hdd in the airduct, it's SATA so cable wouldn't be too much of the hassle. The only issue is higher temp for psu though..umm..

That's partly what the 12cm fan would be for. I think the main issue would be the hard drive noise escaping through the open 5" bays, definitly a non-option for whiny samsung spinpoints.

Well, mine are Seagate 7200.7 (made in China ) so may be I'll try it once I return home. I'm at the airport on the way out for a week now.

Decided to build Bluefront's Birdhouse instead.3 photos here. Hdds temp drop 3-5 C. Upper drive drops more than the lower one.

The whole thing is made of rubber mat (cheap kind of safety mat for kid). All sides are pressed fit together - no glue, no duct tape. The silvery thing is alu tape to cover up cartoon printed on the mat (don't tell my son ).

Good thinking about those cartoons! The only type of safety mat I've been able to find came with the alphabet printed on so I haven't bought it yet... how did you attach the harddisks? What fan size are you using? 92mm?

The whole thing is very much a faithful copy of Bluefront's Birdhouse only different in material used and size. The 2 Hdds just 'sloted in' on both sides of duct. Here're 3 more photos showing material and one side of cut(and cartoon ). If I were to do it again I might cut the slot for lower Hdd in such a way that it moves closer to the fan (2 hdds line up in paralel with fan) - I think this may help improve cooling of lower hdd a bit more).

Last pic was taken on the 'connectors' side of Hdds. Still messy wiring, I hope to rearrange these wires once my new sata cables with angled connectors arrive. You may notice the 90 degree sata power line for the 2 Hdds in the pic. This helps reduce lines clutter.

Fan is a 120mm Globe S1202512L-3M connected through fan control unit.

So far I'm quite happy with this birdhouse. Not only it makes Hdds temp drop, seek noise is now reduced to barely audible.

Just done that. Now 2 Hdds look like a staircase in paralel with 120mm fan. Both Hdds now most of the time have same temp or within 1C of each other - instead of 2-4 C different as in the past.

Having been idled for 20 min. both Hdds show 33C with room temp of 26.5C, and 120 mm Globe fan run at approx 50% duty cycle.

Final modification made to PSU by putting this 80 mm. Enermax Adjustable Speed fan to replace original fan. Both turn out to have same code i.e. B01138812-H-3M, made by Globe .

Since this Enermax fan has a variable resistor of its own. I tune it down a bit more than half of the way (to 1900 rpm at 12v), then connect the fan to my pwm fan control and reduce duty cycle to minimum (about 50%) which make the fan much more quiet than the stock one and with a lot of headroom for cooling potential e.g. when gaming.

3 more photos. In the 1st photo you can also see thermistor lead wedged between grooves of top heatsink. On the left of 2nd photo is where I kept the psu fan variable resistor at the back of case - make it easy for further adjustment when needed.

This should conclude my PSU project. It should have been much easier if I were to put in a Panaflo M as Mike and many other members suggested in various form threads, unfortunately I've earlier chosen on pwm control which is not very friendly with panaflo. Nevertheless, I've learned a lot by doing it and making few mistakes along the way - and having fun too.

EDIT:
Well..said it too early.

I've later put in T-Balancer fan control, which allow its value to be displayed on LCD screen. So I installed a 4x20 character LCD in the middle of air intake. This installation still allows enough cool air to PSU - so no negative temp effect on PSU. 3 more pics here.