Single fan design - rad under psu ok?

Som · 10-30-2002, 08:57 AM

For almost fan-free existence, can a rad be mounted under a modded psu with a 120mm fan pushing air through them both?
What sort of air temps are you likely to get in a large case (over ambient) with, for the sake of argument, an XP1900, GF 3 Ti200 and 512mb DDR PC2100.
I've seen a couple of pics of rigs like this, but don't know if they only work with cooler, low spec cpu etc.
Thanks!

myv65 · 10-30-2002, 09:15 AM

There's a wide range of what's acceptable that is entirely dependent on the end user. Are you planning to overclock? How's your tolerance for noise? What reported temperatures are you willing to live with?

Personally, my criteria is stability and silence and I don't get into overclocking on my main machine. As such, I am perfectly content seeing reported chip temperatures in the upper 50s C range. Yeah, you could probably get away with what you propose, but only if you're willing to live with high temperatures.

If you plan to overclock, your proposal down right stinks.

Som · 10-30-2002, 09:19 AM

Reason I said XP1900 is because that's what my XP1700 is running as (143fsb), so it is overclocked, but that's as high as I need to go (could even back it down a bit).
I want silence! At least during surfing etc. Could turn on some fans for gaming, but I'd rather not.

airspirit · 10-30-2002, 09:24 AM

If you have an efficient radiator, you shouldn't have too much of a worry with frying your PSU. You should note that your water temps are going to be higher, unless you also have a fan blowing air into the case (better air flow, since you are going to be blowing case heated air over your radiator). Accordingly, your CPU temps will be higher. With a decent radiator, expect middle to high road air-cooling temps and enjoy the silence.

Som · 10-30-2002, 09:26 AM

Bix (=Black Ice Extreme? Newbie!) is 'decent rad'?

gmat · 10-30-2002, 09:53 AM

Tests and experience (from BillA amonst others) show the BiX is quite restrictive for the airflow.
You'd better have a fan with high static pressure, and pull air from the rad + push it through the PSU. The said fan will make more noise than a low-spinning PAPST or Panaflo, but still it will be less annoying than a 80mm.
The PAPST 4412 NGML (67cfm / 32dBA) seems a good compromise.
Just make sure the PSU heatsinks receive a decent amount of airflow..

Som · 10-30-2002, 10:04 AM

gmat - right, so a fan sandwich, with maybe blowhole/ducting to cool, external air?

I'm thinking of;
Danger Den Maze 3 1/2 inch
Black Ice Extreme (anything better? - has to fit under psu so nothing huge)
Papst 120mm (temp controlled?)
Danger Den GeForce2/3 block (any good?)
Eheim 1048

How hot can psu's get (how long is a piece of string, I know). Is 50 C internal air temp likely to be ok? At the moment my modded Sparkle 300w runs with a 92mm Papst at 7v and one of the super-silent 12db Papst 80mm. Plenty of airflow, I think more than necessary.

MadDogMe · 10-30-2002, 10:24 AM

Som!, have you seen the pic of a case at coolhardware.co.uk?.

'roll out 2' thread

Could be the person to ask questions to

...

Som · 10-30-2002, 10:28 AM

MadDogMe - Thanks! But mine will be well ghetto!

That pic is certainly what I was thinking about...

nexxo · 10-31-2002, 01:40 PM

Rad under PSU? Sure can do, bro. This man's done so:

Easy-peasy.

Visit :his link: for more pics.

P.S. to all you dial-up folks: I apologise for the size of this pic.
Sorry...

gmat · 10-31-2002, 03:51 PM

Wow neat setup !

Som: you are in UK so forget the BiX - buy 'The Deep' from http://www.overclockedpc.co.uk/
It will fit your needs and be cheaper than the BiX.
Try to stick to 1 fan only... 2 fans = twice the noise.

nexxo · 11-02-2002, 03:45 AM

Yeah, I don't know who he is, but he understands the principles of keeping watercooling simple and elegant... Very impressive. Unfortunately the rad used is a BI pro, not a BIX, which is too large for this setup (would get in the way of the mobo). So I can't go that route...

but it sure is a neat solution.

Som · 11-04-2002, 04:51 AM

From the thread on CoolHardware it seems the pictured (fantastic looking) rig is running a duron which won't be kicking out so much heat as my XP1900. This means the airflow cooling the psu is not so warm.
I'm thinking, how about reversing the psu airflow? Instead of pulling heated air through the rad into the psu, why not bring cool air into the psu first and exhaust it (upwards to blowhole in top of case) through the rad? Will the air be cooler having cooled the psu than other way about? Hmmm...

MadDogMe · 11-04-2002, 09:01 AM

PSU's can get pretty warm. For silence I'd buy an Enermax or Antec they're quiet, mod them to 7V if you want absolute silence. put the rad where you want (bottom front drawing air in seems best) and have the 120mm on it run at 7V...
Cause Nexxo has a point with the room under the PSU, you would'nt get a good performance rad under there:shrug: ...

Vector86 · 11-04-2002, 10:15 AM

if you have enough space between the psu and cpu, u could put a duct on the rad fan to suck in air from outside the case, which should be cooler

Som · 11-05-2002, 07:26 AM

What about this?! (2 minute pic, sorry.)
Needs a big case, obviously, but could work.
Advantage is only one fan for low heat use, but ability to do anything without burning up. Possibly.

My problem with 'normal' rad/fan at bottom front of case is that it needs an extra fan (at least). My current psu has two Papst fans running about 6v and is virtually silent. But I don't want to add another fan to the system!

This would be an expensive setup if it's no good though - have to butcher the top of big tower case to exhaust the air.

gmat · 11-05-2002, 10:38 AM

Make sure you'll have an aitrap *above* that rad or bubbles will be incredibly hard to get out of it...

nexxo · 11-05-2002, 01:22 PM

PSU's will heat up the air a fair bit... Better have the fans suck the air in through the rad, into the PSU. Sucking fans work slightly better anyway.

By the way, a good, quiet PSU may be the Seasonic or PC Power&Cooling PSU. One fan, but that's all that's needed. Don't be fooled by their mundane looks: they're quality PSU's.

10-30-2002, 08:57 AM	#1
Som Cooling Neophyte Join Date: Oct 2002 Location: UK Posts: 17	Single fan design - rad under psu ok? For almost fan-free existence, can a rad be mounted under a modded psu with a 120mm fan pushing air through them both? What sort of air temps are you likely to get in a large case (over ambient) with, for the sake of argument, an XP1900, GF 3 Ti200 and 512mb DDR PC2100. I've seen a couple of pics of rigs like this, but don't know if they only work with cooler, low spec cpu etc. Thanks!

10-30-2002, 09:24 AM	#4
airspirit Been /.'d... have you? Join Date: Jul 2002 Location: Moscow, ID Posts: 1,986	If you have an efficient radiator, you shouldn't have too much of a worry with frying your PSU. You should note that your water temps are going to be higher, unless you also have a fan blowing air into the case (better air flow, since you are going to be blowing case heated air over your radiator). Accordingly, your CPU temps will be higher. With a decent radiator, expect middle to high road air-cooling temps and enjoy the silence. __________________ #!/bin/sh {who;} {last;} {pause;} {grep;} {touch;} {unzip;} mount /dev/girl -t {wet;} {fsck;} {fsck;} {fsck;} {fsck;} echo yes yes yes {yes;} umount {/dev/girl;zip;} rm -rf {wet.spot;} {sleep;} finger: permission denied

10-31-2002, 01:40 PM	#10
nexxo Cooling Savant Join Date: Jul 2002 Location: Brimingham, UK Posts: 385	Rad under PSU? Sure can do, bro. This man's done so: Easy-peasy. Visit :his link: for more pics. P.S. to all you dial-up folks: I apologise for the size of this pic. Sorry... __________________ "There is a thin line between magic and madness"

11-02-2002, 03:45 AM	#12
nexxo Cooling Savant Join Date: Jul 2002 Location: Brimingham, UK Posts: 385	Yeah, I don't know who he is, but he understands the principles of keeping watercooling simple and elegant... Very impressive. Unfortunately the rad used is a BI pro, not a BIX, which is too large for this setup (would get in the way of the mobo). So I can't go that route... but it sure is a neat solution. __________________ "There is a thin line between magic and madness"

11-05-2002, 01:22 PM	#18
nexxo Cooling Savant Join Date: Jul 2002 Location: Brimingham, UK Posts: 385	PSU's will heat up the air a fair bit... Better have the fans suck the air in through the rad, into the PSU. Sucking fans work slightly better anyway. By the way, a good, quiet PSU may be the Seasonic or PC Power&Cooling PSU. One fan, but that's all that's needed. Don't be fooled by their mundane looks: they're quality PSU's. __________________ "There is a thin line between magic and madness"

10-30-2002, 09:15 AM	#2
myv65 Cooling Savant Join Date: May 2002 Location: home Posts: 365	There's a wide range of what's acceptable that is entirely dependent on the end user. Are you planning to overclock? How's your tolerance for noise? What reported temperatures are you willing to live with? Personally, my criteria is stability and silence and I don't get into overclocking on my main machine. As such, I am perfectly content seeing reported chip temperatures in the upper 50s C range. Yeah, you could probably get away with what you propose, but only if you're willing to live with high temperatures. If you plan to overclock, your proposal down right stinks.

10-30-2002, 09:19 AM	#3
Som Cooling Neophyte Join Date: Oct 2002 Location: UK Posts: 17	Reason I said XP1900 is because that's what my XP1700 is running as (143fsb), so it is overclocked, but that's as high as I need to go (could even back it down a bit). I want silence! At least during surfing etc. Could turn on some fans for gaming, but I'd rather not.

10-30-2002, 09:26 AM	#5
Som Cooling Neophyte Join Date: Oct 2002 Location: UK Posts: 17	Bix (=Black Ice Extreme? Newbie!) is 'decent rad'?

10-30-2002, 09:53 AM	#6
gmat Thermophile Join Date: Mar 2001 Location: France Posts: 1,221	Tests and experience (from BillA amonst others) show the BiX is quite restrictive for the airflow. You'd better have a fan with high static pressure, and pull air from the rad + push it through the PSU. The said fan will make more noise than a low-spinning PAPST or Panaflo, but still it will be less annoying than a 80mm. The PAPST 4412 NGML (67cfm / 32dBA) seems a good compromise. Just make sure the PSU heatsinks receive a decent amount of airflow..

10-30-2002, 10:04 AM	#7
Som Cooling Neophyte Join Date: Oct 2002 Location: UK Posts: 17	gmat - right, so a fan sandwich, with maybe blowhole/ducting to cool, external air? I'm thinking of; Danger Den Maze 3 1/2 inch Black Ice Extreme (anything better? - has to fit under psu so nothing huge) Papst 120mm (temp controlled?) Danger Den GeForce2/3 block (any good?) Eheim 1048 How hot can psu's get (how long is a piece of string, I know). Is 50 C internal air temp likely to be ok? At the moment my modded Sparkle 300w runs with a 92mm Papst at 7v and one of the super-silent 12db Papst 80mm. Plenty of airflow, I think more than necessary.

10-30-2002, 10:24 AM	#8
MadDogMe Thermophile Join Date: Aug 2002 Location: Just shut up ;) ... Posts: 1,068	Som!, have you seen the pic of a case at coolhardware.co.uk?. 'roll out 2' thread Could be the person to ask questions to ...

10-30-2002, 10:28 AM	#9
Som Cooling Neophyte Join Date: Oct 2002 Location: UK Posts: 17	MadDogMe - Thanks! But mine will be well ghetto! That pic is certainly what I was thinking about...

10-31-2002, 03:51 PM	#11
gmat Thermophile Join Date: Mar 2001 Location: France Posts: 1,221	Wow neat setup ! Som: you are in UK so forget the BiX - buy 'The Deep' from http://www.overclockedpc.co.uk/ It will fit your needs and be cheaper than the BiX. Try to stick to 1 fan only... 2 fans = twice the noise.

11-04-2002, 04:51 AM	#13
Som Cooling Neophyte Join Date: Oct 2002 Location: UK Posts: 17	From the thread on CoolHardware it seems the pictured (fantastic looking) rig is running a duron which won't be kicking out so much heat as my XP1900. This means the airflow cooling the psu is not so warm. I'm thinking, how about reversing the psu airflow? Instead of pulling heated air through the rad into the psu, why not bring cool air into the psu first and exhaust it (upwards to blowhole in top of case) through the rad? Will the air be cooler having cooled the psu than other way about? Hmmm...

11-04-2002, 09:01 AM	#14
MadDogMe Thermophile Join Date: Aug 2002 Location: Just shut up ;) ... Posts: 1,068	PSU's can get pretty warm. For silence I'd buy an Enermax or Antec they're quiet, mod them to 7V if you want absolute silence. put the rad where you want (bottom front drawing air in seems best) and have the 120mm on it run at 7V... Cause Nexxo has a point with the room under the PSU, you would'nt get a good performance rad under there:shrug: ...

11-04-2002, 10:15 AM	#15
Vector86 Cooling Savant Join Date: Jun 2002 Location: KANSAS "it's not just cows"! Posts: 211	if you have enough space between the psu and cpu, u could put a duct on the rad fan to suck in air from outside the case, which should be cooler

11-05-2002, 10:38 AM	#17
gmat Thermophile Join Date: Mar 2001 Location: France Posts: 1,221	Make sure you'll have an aitrap above that rad or bubbles will be incredibly hard to get out of it...

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)