Ducting PC case - please advise

[sirpico]

I am planning to duct my PC case for more good airflow.
But I'm not modding expert just a new beginner.
Please view my diagram if you may have any suggestion.

Thank you so much

(blue lines are the duct made with 3mm. foam core and cardboard.
Side panel fan duct is for Graphic Card only.)



BTW, I live in Bangkok, Thailand where temp. is very hot all the time.

[qviri]

That side fan an intake?

If so, you'll have a massively positive-pressure case, what with two 120mm intakes and (at most) 80mm case fan and 120mm PSU fan that are outtakes.

[Poodle]

Scrap the 80 mm and build a duct from the cpu tower cooler to the rear case wall. In this way the cpu cooler acts as a case fan aswell. If there's enough free area on the back case you could also make the opening a bit bigger to ease the airflow.

you could build one with plastic like this: http://www.silentpcreview.com/article310-page6.html

So I would do that then instead of a duct from the front in the lower case as in your pic I would do one in the top from the 5 1/4 to the psu and move down the optical drive to the lowest 5 1/4 slot. Like MikeC did with the p150 that he sent to his friend in Thailand. Maybe to someone you know
http://www.silentpcreview.com/article293-page3.html
This way your psu gets fresh air.


Then you could have the two intake fans on as low voltage as possible as long as they can start. Maybe you could have them on lower voltage than 5V even.

I'm a big fetish of seperate airflow ducting....

[sirpico]

Thanks for suggestion.

I've tried many ways to duct my PC with foamcore and cardboard.
I still unsatisfied with the result. Especially, my duct design for VGA card doesn't work. I thought I could cool my VGA card down if I made a room under VGA card and place a 9cm fan to blow cool air from front to the back of case. But I was wrong, nothing happened but temperature increased about 5 degree.

Please view my pic and feel free to comment.



Diagram of ducting design

[IsaacKuo]

Here's my suggestion:

Get rid of the VGA ducting. Open up ALL of the PCI slot backplanes. Remove all case fans except for the front fan and the side fan--both set to blow air into the case.

As it is, it's questionable how much effect your rear case fan is having because there are so many other rear case holes.

If this produces acceptable temperatures, then you can maybe work on reducing noise by removing the CPU fan. This involves creating a partition across the CPU heatsink, with a hole where the CPU heatsink is. (Something like this: Midfan File Server)

With a partition ACROSS the CPU heatsink, all air is forced to pass through the CPU heatsink. Thus, no CPU fan is required.

One good rule of thumb to keep in mind is to balance intake and exhaust areas. As such, your attempt at cooling the VGA card is bottlenecked by the tiny exhaust--just one PCI slot! That's a tiny amount of area compared to the 90mm fan, resulting in backpressure and low airflow.

[ultrachrome]

Your case is more baffled than ducted.

To start I would remove your existing baffles and duct your CPU heatsink as depicted below. Make the duct as tight fitting as possible and covers the entire heatsink. Try different combinations of using just the CPU fan, just the case fan, and both.

The back of your case looks somewhat restricted so you might want to cut out a larger opening where the exhaust fan would go. You might also want to reposition the case fan so it is right behind the CPU heatsink instead of slightly below it.

The PSU fan, in theory should pull air into the case over your HDD and through the open slot next to your VGA card. I think by trying to blow air past your VGA card and out the open slot will be fighting the PSU fan.

Your duct will pull in some warm air created by the motherboard, VGA card, and HDD but it shouldn't be that much. More importantly the hot air created by the CPU will be quickly expelled from the case.

[Trunks]

Open up ALL of the PCI slot backplanes.

I think this is a guaranteed way to make your computer louder. The x1600 has a little fan on it. and lets the HD noise go right out.



The heat from your video card will travel up from convection. The fan blows out the back. That lower fan could be in a better place.

For quietness you should having all the PCI slots closed. Not using the side case fan (seal the hole). Move the hard drive down. So that the fan just blows air across the top. This should let the air move more freely in to the case. lose all of your ducts at first. Remove the rear grill, and get a 120 mm fan for the back.

Block the extra holes right above the rear fan.

[IsaacKuo]

Open up ALL of the PCI slot backplanes.

I think this is a guaranteed way to make your computer louder.

With all due respect, this is flat out wrong. I've used open PCI slots to great effect in producing SILENT computers. I'm increasingly of the opinion that the PCI slots are the IDEAL place to get intake air from, from a silencing perspective.

No matter what, you need to get air into the computer. That means you need to have some openings. If you open up the PCI backplanes, then that means the openings are to the rear. If you don't open up the PCI backplanes, then that means that either you don't have enough intake area or you've got openings to the front. Openings in the front generally mean more noise than openings in the rear.

For quietness you should having all the PCI slots closed.

If you want a quiet computer, close up all of the front intakes with noise-blocking material and get all your intake air from the rear--the PCI slots. However, this requires some amount of customization to force air to travel forward to the typical hard drive location.

[Shobai]

on a harmless [slightly off topic] note, OP you have some mad paint skillz! larfs, what did oyu use to make your pictures?

also, i realise the top partitions are to guide air through the heatsink, but do you have an air intake in the 5 1/4" bays to give your PSU some air? i suspect you do, but just in case..it seems like that'd make some form of PSU duct anyway, without having to worry about moving drives. you'd definately have cables ruining smooth airflow, but the extra volume should help, i spose.

[cmthomson]

Thanks for suggestion.

I've tried many ways to duct my PC with foamcore and cardboard.
I still unsatisfied with the result. Especially, my duct design for VGA card doesn't work. I thought I could cool my VGA card down if I made a room under VGA card and place a 9cm fan to blow cool air from front to the back of case. But I was wrong, nothing happened but temperature increased about 5 degree.

This result is not surprising. The problem is that there is nowhere for the hot air to go, so it just swirls around inside the case heating up everything.

I suggest you reverse your thinking. Instead of concentrating on how to get cool air to the CPU and VGA, think about how to get the hot air away from them.

This will certainly lead you to creating more exhaust openings or larger exhaust fans. As was pointed out above, the outlets have to be at least as large as the intakes for good airflow, especially if you use intake fans, and this is definitely not true as you've drawn your system.

Also, does your PSU draw air from the front, the bottom or both. If it is from the front, your CPU baffle is making things worse, because the PSU is not able to exhaust any hot air from the case.

In my system, I doubled the cross section of the intakes, so they would roughly match the cross section of the outlets, with good success. See the section "OPENING UP THE UNUSED 5.25" BAYS FOR BETTER AIR FLOW" in my DIY article for some pictures. http://www.silentpcreview.com/article595-page2.html

[Le_Gritche]

I think sirpico is more interested in better airflow than better silencing, at least that's what I understand by reading his first sentence : "I am planning to duct my PC case for more good airflow."
So I will try to answer with that in mind, even though we should quiet his computer at the same time because he probably came specifically to SPCR for a reason.

To begin I have some questions :
- what do you want to cool better, and what are the noise emitters you want to reduce ?
- where is located the fan of your PSU ? (right over the CPU heatsink, or on the back of the case)
- where are the intake openings of the PSU ? (only over the CPU heatsink, mainly towards the DVD, ...)

I've tried many ways to duct my PC with foamcore and cardboard.
I still unsatisfied with the result. Especially, my duct design for VGA card doesn't work. I thought I could cool my VGA card down if I made a room under VGA card and place a 9cm fan to blow cool air from front to the back of case. But I was wrong, nothing happened but temperature increased about 5 degree.

I think there isn't enough openings in the PCI slots to exhaust air comming from the 90mm fan. But I will first advise you to move that 90mm fan upward or turn it so that it blows air directly on the VGA card (and not under it as is currently the situation).
After that, if improvements are still needed you can open one more PCI slot to give enough room for the airflow from the 90mm fan to go out.
These two points have already been mentionned so I will add one : duct the space between the VGA and the side panel so that airflow can't go upward toward the 80mm case fan.

I think your duct from the front intake fan all the way to the CPU is too long to be efficient, there will be escape holes in too many place for you to seal everything off. You should concentrate your efforts on the rear of the case.
Ultrachrome has a good idea about ducting your CPU heatsink to the rear opening and removing the 80mm exhaust fan. It's obvious that 2 fans so close and blowing in the same direction are one too many.
But your PSU is very close, that's why I asked you if there's is a PSU fan right there. Because ducting the CPU heatsink to the rear opening would seriously hinder the airflow of the PSU fan.
Anyway that duct would allow to get rid of the hot air from the CPU more efficiently, hopefully reducing the inside temperature somewhat.

If your PSU intake is mainly toward the DVD you could do a so-called "fresh air duct" with an open 5"1/4 bay as the intake (poodle already told you about that). But that would reduce the exhaust openings, and you could be left with too much of a positive pressure. Besides, the PSU exhaust is probably usefull to cool your case and hot CPU. Without knowing your temperatures nor the setup and noise of your PSU it's hard to decide if that is worth the trouble.

BTW have you tried the different methods to reduce the heat produced by your computer (undervolting and underclocking the CPU and VGA mainly) ? Because your P630 has probably a TDP of 90W or more, easily cooking the VGA card under. Thus, you should first concentrate on cooling and ducting the CPU.

[IsaacKuo]

Also, does your PSU draw air from the front, the bottom or both. If it is from the front, your CPU baffle is making things worse, because the PSU is not able to exhaust any hot air from the case.

I've been working under the assumption that the PSU is a straight-thru type. The sort of partition he has ducting the 5.25" bays to the PSU is pretty common here on SPCR. The goal is to PREVENT hot air from reaching the PSU. Thus, the PSU fan doesn't need to ramp up in order to keep PSU temps low. This is the principle behind the P180's lower PSU chamber. Whether this is a good thing to do or not is a matter of debate and depends on one's components and goals.

[ultrachrome]

Le Gritche has a good point. I should have looked more carefully. If your PSU draws air from the bottom, there isn't really enough room for duct.

Another option is possible if there is any room between the top of the PSU and the top of the case. If you have about a half inch, you could flip the PSU over and it could draw air from the top of the case.

Since the duct would be removing the bulk of the hot air from the case, the PSU won't have to move a lot of air.

Is a new case a possibility for you? With a little more room you would have some more options.

[sirpico]

thank you all for many interesting ideas.
I think I will try the way of ducting from your suggestions one by one.

About my PSU, it draws air from front.

My PC temp.
CPU = 56-59 C
MB = 51-54 C
VGA = 60 C (if playing HL2 >= 70 C)
HDD = 41 C

I think another reason that make my PC heating up is the ambience temperature. It's summer in Bangkok right now, temp is around 36-38 C.

[Trunks]

Open up ALL of the PCI slot backplanes.

I think this is a guaranteed way to make your computer louder.

With all due respect, this is flat out wrong. I've used open PCI slots to great effect in producing SILENT computers. ...

It is not my goal to disagree with you for sake of general philosophy…
This will not be a silent case with out replacing the video card HSF.
The OP wanted advice on ducting.

In this specific case…a video card with a little zippy fan on it that is next to an open PCI slot (like the x1600 on 100%) will be heard more than if that slot is covered. The open slot is simply a direct path for sound to escape.

...Openings in the front generally mean more noise than openings in the rear...

If you are measuring sound from the front of the case sure. I guess openings near the hard drive potentially let that noise escape, and hard drives are generally in the front.

[Tephras]

...Openings in the front generally mean more noise than openings in the rear...

If you are measuring sound from the front of the case sure. I guess openings near the hard drive potentially let that noise escape, and hard drives are generally in the front.

Most often a computer is positioned with the front towards the user, that's why it's more likely that the perceived noise level will be higher with openings in the front of the case compared to openings in the back.