Cool quiet fast PC in hot dusty house - Comments and PSU a..

[Guest]

Archived from groups: uk.comp.homebuilt,alt.comp.hardware.pc-homebuilt (More info?)

My current PC got far too hot last summer, and is due for replacement
anyway, so I'm planning on rebuilding.

I'm looking to achieve a sensibly quiet PC that will perform reliably
in a house that gets dusty (it's being restored), and hot (45 deg C
outside last summer, but rather cooler indoors)

I'll keep my case - it's a Chieftec Scorpio, and I'm happy with it,
but I'm replacing all the fans with Noiseblocker Ultra Silent Fan S4's
with BoogieBug anti-dust filters - two intake in the front, two
exhaust (not including PSU) at the back, and one intake in the side
that blows at the CPU.

The rest of the rig:

Motherboard ABIT AN7
CPU AMD Athlon XP3200+ Barton 400Mhz FSB
RAM Corsair XMS 512 Mo DDR PC3200
GPU Asus Radeon A9800XT-TVD /256
HDD's 2 x Seagate Barracuda 7200.7 - 160G - SAT
Heatsink Thermalright SP97 + Noiseblocker Ultra Silent Fan S4

(plus a LiteOn CDRW, and a Creative SB Live 5.1)

My first problem is the PSU - as has been mentioned here before,
finding good, in dependant reviews that cover noise and power output
for PSUs seems tricky.

So far I've narrowed it down to:

Enermax EG465AX-VE(G) FMA (460w 'Super Low Noise')
Zalman ZM400B-APS (400w)
Q-Technology SIL-Q400 (400 Watts - Double Papst Fan)

....but I need to be sure that there's enough good power for all the
kit above and that the noise level will be satisfyingly low.

Also, how noisy will the Radeon 9800XT be, and is there anything to be
done about that?

Finally, any general advice appreciated

Cheers


--
Charlie

 

[Guest]

Archived from groups: uk.comp.homebuilt,alt.comp.hardware.pc-homebuilt (More info?)

the noiseblocker fans are not quiet, even the slower S2s make more noise
than a panaflo L1A. i'd use panaflo L1As or nexus real silent fans for the
case fans and maybe a panaflo M1BX for the CPU if you really need the extra
cfm.

the seasonic super silencer or enermax "noisetaker" are both good, quiet
PSUs and the most efficient currently available.

those little 40mm video card fans can be really annoying. take a look at the
sapphire 9800XT ultimate.

also, the samsung SP1614Cs are quieter than the seagate hard drives.

"Charlie King" <charlie@removethisitsaspamtrap.stopthatitssilly.com> wrote
in message news:c4h3ja$f0t$1@news-reader5.wanadoo.fr...
> My current PC got far too hot last summer, and is due for replacement
> anyway, so I'm planning on rebuilding.
>
> I'm looking to achieve a sensibly quiet PC that will perform reliably
> in a house that gets dusty (it's being restored), and hot (45 deg C
> outside last summer, but rather cooler indoors)
>
> I'll keep my case - it's a Chieftec Scorpio, and I'm happy with it,
> but I'm replacing all the fans with Noiseblocker Ultra Silent Fan S4's
> with BoogieBug anti-dust filters - two intake in the front, two
> exhaust (not including PSU) at the back, and one intake in the side
> that blows at the CPU.
>
> The rest of the rig:
>
> Motherboard ABIT AN7
> CPU AMD Athlon XP3200+ Barton 400Mhz FSB
> RAM Corsair XMS 512 Mo DDR PC3200
> GPU Asus Radeon A9800XT-TVD /256
> HDD's 2 x Seagate Barracuda 7200.7 - 160G - SAT
> Heatsink Thermalright SP97 + Noiseblocker Ultra Silent Fan S4
>
> (plus a LiteOn CDRW, and a Creative SB Live 5.1)
>
> My first problem is the PSU - as has been mentioned here before,
> finding good, in dependant reviews that cover noise and power output
> for PSUs seems tricky.
>
> So far I've narrowed it down to:
>
> Enermax EG465AX-VE(G) FMA (460w 'Super Low Noise')
> Zalman ZM400B-APS (400w)
> Q-Technology SIL-Q400 (400 Watts - Double Papst Fan)
>
> ...but I need to be sure that there's enough good power for all the
> kit above and that the noise level will be satisfyingly low.
>
> Also, how noisy will the Radeon 9800XT be, and is there anything to be
> done about that?
>
> Finally, any general advice appreciated
>
> Cheers
>
>
> --
> Charlie

 

[nightic]

Archived from groups: uk.comp.homebuilt,alt.comp.hardware.pc-homebuilt (More info?)

"Charlie King" <charlie@removethisitsaspamtrap.stopthatitssilly.com> wrote
in message news:c4h3ja$f0t$1@news-reader5.wanadoo.fr...
> My current PC got far too hot last summer, and is due for replacement
> anyway, so I'm planning on rebuilding.
>
> I'm looking to achieve a sensibly quiet PC that will perform reliably
> in a house that gets dusty (it's being restored), and hot (45 deg C
> outside last summer, but rather cooler indoors)
>
> I'll keep my case - it's a Chieftec Scorpio, and I'm happy with it,
> but I'm replacing all the fans with Noiseblocker Ultra Silent Fan S4's
> with BoogieBug anti-dust filters - two intake in the front, two
> exhaust (not including PSU) at the back, and one intake in the side
> that blows at the CPU.
>
> The rest of the rig:
>
> Motherboard ABIT AN7
> CPU AMD Athlon XP3200+ Barton 400Mhz FSB
> RAM Corsair XMS 512 Mo DDR PC3200
> GPU Asus Radeon A9800XT-TVD /256
> HDD's 2 x Seagate Barracuda 7200.7 - 160G - SAT
> Heatsink Thermalright SP97 + Noiseblocker Ultra Silent Fan S4



Can't say that I'd recommend the SP-97 for a quiet cooling solution (having
owned one until quite recently).
While it is likely still the finest 'performance cooling' heatsink for
Socket A, it's design (tight fin structure) isn't sympathetic to low CFM
fans with a low output pressure.
IMHO for your needs the Zalman CPNS7000A-Cu would be a better bet.

 

[Guest]

Archived from groups: uk.comp.homebuilt,alt.comp.hardware.pc-homebuilt (More info?)

On Fri, 2 Apr 2004 13:17:24 +0100, in
<c4jlka$2j7uko$1@ID-211415.news.uni-berlin.de>
(alt.comp.hardware.pc-homebuilt) "nightic"
<nighticREMOVECAPS@hotmail.com> wrote:

> > Motherboard ABIT AN7
> > CPU AMD Athlon XP3200+ Barton 400Mhz FSB
> > RAM Corsair XMS 512 Mo DDR PC3200
> > GPU Asus Radeon A9800XT-TVD /256
> > HDD's 2 x Seagate Barracuda 7200.7 - 160G - SAT
> > Heatsink Thermalright SP97 + Noiseblocker Ultra Silent Fan S4
>
>
>
> Can't say that I'd recommend the SP-97 for a quiet cooling solution (having
> owned one until quite recently).
> While it is likely still the finest 'performance cooling' heatsink for
> Socket A, it's design (tight fin structure) isn't sympathetic to low CFM
> fans with a low output pressure.
> IMHO for your needs the Zalman CPNS7000A-Cu would be a better bet.
>

I did think about the Zalman, but Zalman's site lists it as
incompatible with the motherboard.


--
Charlie

 

[Guest]

Archived from groups: uk.comp.homebuilt,alt.comp.hardware.pc-homebuilt (More info?)

On Fri, 2 Apr 2004 13:17:24 +0100, in
<c4jlka$2j7uko$1@ID-211415.news.uni-berlin.de> (uk.comp.homebuilt)
"nightic" <nighticREMOVECAPS@hotmail.com> wrote:

> > Motherboard ABIT AN7
> > CPU AMD Athlon XP3200+ Barton 400Mhz FSB
> > RAM Corsair XMS 512 Mo DDR PC3200
> > GPU Asus Radeon A9800XT-TVD /256
> > HDD's 2 x Seagate Barracuda 7200.7 - 160G - SAT
> > Heatsink Thermalright SP97 + Noiseblocker Ultra Silent Fan S4
>
>
>
> Can't say that I'd recommend the SP-97 for a quiet cooling solution (having
> owned one until quite recently).
> While it is likely still the finest 'performance cooling' heatsink for
> Socket A, it's design (tight fin structure) isn't sympathetic to low CFM
> fans with a low output pressure.
> IMHO for your needs the Zalman CPNS7000A-Cu would be a better bet.

Following your, and a couple of other folks', comments, I've started
thinking that I'd be better off with an Asus A7N8X-E Deluxe
motherboard, which would allow me to go with the Zalman CPNS7000A-Cu
fan, and save about 4 euros into the bargain

Any comments on the Asus A7N8X-E Deluxe?
--
Charlie

 

[nightic]

Archived from groups: uk.comp.homebuilt,alt.comp.hardware.pc-homebuilt (More info?)

"Charlie King" <charlie@removethisitsaspamtrap.stopthatitssilly.com> wrote
in message news:c4pbge$29v$1@news-reader2.wanadoo.fr...
> On Fri, 2 Apr 2004 13:17:24 +0100, in
> <c4jlka$2j7uko$1@ID-211415.news.uni-berlin.de> (uk.comp.homebuilt)
> "nightic" <nighticREMOVECAPS@hotmail.com> wrote:
>
> > > Motherboard ABIT AN7
> > > CPU AMD Athlon XP3200+ Barton 400Mhz FSB
> > > RAM Corsair XMS 512 Mo DDR PC3200
> > > GPU Asus Radeon A9800XT-TVD /256
> > > HDD's 2 x Seagate Barracuda 7200.7 - 160G - SAT
> > > Heatsink Thermalright SP97 + Noiseblocker Ultra Silent Fan S4
> >
> >
> >
> > Can't say that I'd recommend the SP-97 for a quiet cooling solution
(having
> > owned one until quite recently).
> > While it is likely still the finest 'performance cooling' heatsink for
> > Socket A, it's design (tight fin structure) isn't sympathetic to low CFM
> > fans with a low output pressure.
> > IMHO for your needs the Zalman CPNS7000A-Cu would be a better bet.
>
> Following your, and a couple of other folks', comments, I've started
> thinking that I'd be better off with an Asus A7N8X-E Deluxe
> motherboard, which would allow me to go with the Zalman CPNS7000A-Cu
> fan, and save about 4 euros into the bargain
>
> Any comments on the Asus A7N8X-E Deluxe?
> --
> Charlie



It's a good board, owned one myself a while back - fully featured though
really not for the overclocker.
My money would be on the DFI Ultra Infinity, especially if you plan on
overclocking.
This would still allow use of the Zalman and would save even more money.

 

[Guest]

Archived from groups: uk.comp.homebuilt,alt.comp.hardware.pc-homebuilt (More info?)

"Isaac Kuo" <mechdan@yahoo.com> wrote in message
news:acc26c07.0404011429.4a7b5033@posting.google.com...
> Charlie King <charlie@removethisitsaspamtrap.stopthatitssilly.com> wrote
in message news:<c4h3ja$f0t$1@news-reader5.wanadoo.fr>...
>
> >I'm looking to achieve a sensibly quiet PC that will perform reliably
> >in a house that gets dusty (it's being restored), and hot (45 deg C
> >outside last summer, but rather cooler indoors)
>
> For an example of a serious homebrew case mod which combines
> air filters with muffling, see:
>
> http://www.silentpcreview.com/article103-page1.html

Umm, you lost me there. That filters the air LEAVING the PC. I don't get
it.

 

[Guest]

Archived from groups: uk.comp.homebuilt,alt.comp.hardware.pc-homebuilt (More info?)

> in a house that gets dusty (it's being restored)

So industrial environment - continual brick/wood/cement dust

> (45 deg C outside last summer, but rather cooler indoors)

Ambient of 45oC is not fun to design for re lower delta-T between
the ambient air & the object to be cooled by air velocity over it.

Personally, I'd do the following:
o Wooden box to enclose any PC case
o Door with simple rebate & draught excluder
o A/C filter panel inset into door, 2" thick, cardboard frame, 5 Euros
---- ask for the resistance (Pa) v velocity (m/sec) at Free / 50% clogged
---- since resistance (Pa) rises with air velocity, you use a big filter
o Rear exhaust fan 150/172mm 12/24V rear fan run at 12/24V
---- want a Pa figure high enough to retain ok cfm at filter 50% clogged
o Foam airflow-bypass-preventer around the PC in the box
---- forcing exhaust fan to pull air out thro the case vs bypassing it

Static resistance v airflow v ambient is the problem here.
So perhaps use an entire side as filter area - eg, 18"x18", so you are
minimising static resistance, boosting airflow & allowing 1x 172mm fan.
Just requires a change in the location of the foam to prevent bypass.

You can't use normal low-profile tubeaxial fans in this application:
o You are using a filter + dusty environment
---- Filter resistance is in the 10s of Pa + clogging relatively quick
o Your ambient temperature is very high
---- so high airflow is required despite losses due to filtration
o Small 38mm-depth tubeaxial do a few 10's Pa at 0cfm
---- your filter will offer a few 10's Pa whilst maintaining 100cfm

Papst & Comair Rotron do 150/172mm fans that will suit, and
you can often find them at good prices on Ebay. You would have
quite a struggle - or noise - using 120x38mm fans to achieve same.

The bigger you can make the filtered intake, the longer it will take
to clog in a such a very dusty environment & easier to get high cfm.
--
Dorothy Bradbury
http://homepage.ntlworld.com/dorothy.bradbury/panaflo.htm (Direct)

 

[Guest]

Archived from groups: uk.comp.homebuilt,alt.comp.hardware.pc-homebuilt (More info?)

In article <rMhcc.9352$4N3.7306@newsfe1-win>,
Dorothy Bradbury <dorothy.bradbury@ntlworld.com> wrote:
>> in a house that gets dusty (it's being restored)
>
>So industrial environment - continual brick/wood/cement dust
>
>> (45 deg C outside last summer, but rather cooler indoors)
>
>Ambient of 45oC is not fun to design for re lower delta-T between
>the ambient air & the object to be cooled by air velocity over it.
>
>Personally, I'd do the following:
>o Wooden box to enclose any PC case
>o Door with simple rebate & draught excluder
>o A/C filter panel inset into door, 2" thick, cardboard frame, 5 Euros
>---- ask for the resistance (Pa) v velocity (m/sec) at Free / 50% clogged
>---- since resistance (Pa) rises with air velocity, you use a big filter
>o Rear exhaust fan 150/172mm 12/24V rear fan run at 12/24V
>---- want a Pa figure high enough to retain ok cfm at filter 50% clogged
>o Foam airflow-bypass-preventer around the PC in the box
>---- forcing exhaust fan to pull air out thro the case vs bypassing it
>
>Static resistance v airflow v ambient is the problem here.
>So perhaps use an entire side as filter area - eg, 18"x18", so you are
>minimising static resistance, boosting airflow & allowing 1x 172mm fan.
>Just requires a change in the location of the foam to prevent bypass.
>
>You can't use normal low-profile tubeaxial fans in this application:
>o You are using a filter + dusty environment
>---- Filter resistance is in the 10s of Pa + clogging relatively quick
>o Your ambient temperature is very high
>---- so high airflow is required despite losses due to filtration
>o Small 38mm-depth tubeaxial do a few 10's Pa at 0cfm
>---- your filter will offer a few 10's Pa whilst maintaining 100cfm
>
>Papst & Comair Rotron do 150/172mm fans that will suit, and
>you can often find them at good prices on Ebay. You would have
>quite a struggle - or noise - using 120x38mm fans to achieve same.
>
>The bigger you can make the filtered intake, the longer it will take
>to clog in a such a very dusty environment & easier to get high cfm.
>--
>Dorothy Bradbury
>http://homepage.ntlworld.com/dorothy.bradbury/panaflo.htm (Direct)
>

Dorothy sounds like she knows what she's talking about. All I can add
is that you should set up overtemp alarms. Your ambient (45C) is so
close to the conservative MAX that you might fry the system as soon as
a fan fails.

I use these audio alarms that screem when heated to 110DegF;

http://www.pcpowercooling.com/products/cooling/alert/index.htm

45C is 113F. On the first hot day, with a clogged filter the alarm
might save your machine. I like to put these gadgets next to my disk
drives. Most of the spec sheets for disk drives I've looked
at say disks like to be kept below 115F.

45C is hot enough that I'd consider running the CPU at a lower clock
speed, which make it run cooler. Maybe the same thing for the video
card and the bridge chips, if your mobo allows it.




--
Al Dykes
-----------
adykes at p a n i x . c o m

 

[Guest]

Archived from groups: uk.comp.homebuilt,alt.comp.hardware.pc-homebuilt (More info?)

Dorothy Bradbury wrote:
>
> > in a house that gets dusty (it's being restored)
>
> So industrial environment - continual brick/wood/cement dust

Perhaps an ionizer in your PC room would help? I have one, and they
clean the air silently. It's not just good for the PC, it's good for
you.

 

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Archived from groups: uk.comp.homebuilt,alt.comp.hardware.pc-homebuilt (More info?)

"jeffc" <nobody@nowhere.com> wrote in message news:<4071782f_1@news1.prserv.net>...
> "Isaac Kuo" <mechdan@yahoo.com> wrote in message
> news:acc26c07.0404011429.4a7b5033@posting.google.com...
> > Charlie King <charlie@removethisitsaspamtrap.stopthatitssilly.com> wrote
> in message news:<c4h3ja$f0t$1@news-reader5.wanadoo.fr>...

> > >I'm looking to achieve a sensibly quiet PC that will perform reliably
> > >in a house that gets dusty (it's being restored), and hot (45 deg C
> > >outside last summer, but rather cooler indoors)

> > For an example of a serious homebrew case mod which combines
> > air filters with muffling, see:

> > http://www.silentpcreview.com/article103-page1.html

> Umm, you lost me there. That filters the air LEAVING the PC. I don't get
> it.

Umm, you lost yourself there. It filters the air ENTERING the PC.
You don't get it.

That article explains in good detail how the mod works and
how he constructed it.

Isaac Kuo

 

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"jeffc" <nobody@nowhere.com> wrote in message news:<4072c549_4@news1.prserv.net>...
> "Isaac Kuo" <mechdan@yahoo.com> wrote in message
> news:acc26c07.0404052030.15563e4d@posting.google.com...

> > > > For an example of a serious homebrew case mod which combines
> > > > air filters with muffling, see:

> > > > http://www.silentpcreview.com/article103-page1.html

> > > Umm, you lost me there. That filters the air LEAVING the PC. I don't
> get
> > > it.

> > Umm, you lost yourself there. It filters the air ENTERING the PC.
> > You don't get it.

> Isn't that what I just said? I don't get it?

If you don't get it, then please try reading the article
linked above. It explains everything, with plenty of
pictures.

Sorry, I just didn't see the need to explain how bluefront's
case works seeing as he's already done an excellent job of
it in the above link. Unlike my usenet posting, his web
site article can include helpful explanatory pictures (and
it does).

> Alright, on closer inspection
> I see the intake and exhaust are right next to each other. This doesn't
> look like a very good design to me.

They aren't next to each other.

The intake is at the top rear. The exhaust is at the front
bottom. This exhaust goes downward into the big huge
muffler that the case sits on top of. The exhaust isn't
anywhere near the intake.

> You've got air blowing
> into the computer, and right at the same spot you've got air blowing right
> back out. Most of that air simply goes in and then back out the power
> supply, not generating nearly the same amount of airflow over the
> motherboard as if the intake were in the front bottom of the computer case.

Well, that might be true except that it's not.

The main airflow of the case goes from the top rear intake
to the front bottom exhaust.

Just curious, you did see the huge wooden box with a tailpipe
that the case is sitting on top of in the pictures, right?
What did you think it was?

Isaac Kuo

 

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Archived from groups: uk.comp.homebuilt,alt.comp.hardware.pc-homebuilt (More info?)

"Isaac Kuo" <mechdan@yahoo.com> wrote in message
news:acc26c07.0404061146.78dc82e8@posting.google.com...
>
> If you don't get it, then please try reading the article
> linked above. It explains everything, with plenty of
> pictures.
>
> Sorry, I just didn't see the need to explain how bluefront's
> case works seeing as he's already done an excellent job of
> it in the above link.

If it does what you say it does, then no, he hasn't. Look at the link
again. In the rear of the case, there is a filter over one of the fans
(what do you think that foam piece is covering?) Now are you going to tell
me he's filtering the air LEAVING the computer? If so, that is WEIRD, and
even so what is the point of that bizarre filter design? That leads me to
believe that filter is filtering INPUT air. If so, then are you saying the
PSU blows air IN? I doubt it. Therefor, you've got a fan blowing in
directly below the PSU fan blowing out. That's not a very good design. If
this is not the case, then please explain, because if I'm wrong then that
diagram is way too confusing.

 

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Archived from groups: uk.comp.homebuilt,alt.comp.hardware.pc-homebuilt (More info?)

jeffc wrote:
> "Isaac Kuo" <mechdan@yahoo.com> wrote in message
> news:acc26c07.0404061146.78dc82e8@posting.google.com...
>>
>> If you don't get it, then please try reading the article
>> linked above. It explains everything, with plenty of
>> pictures.
>>
>> Sorry, I just didn't see the need to explain how bluefront's
>> case works seeing as he's already done an excellent job of
>> it in the above link.
>
> If it does what you say it does, then no, he hasn't. Look at the link
> again. In the rear of the case, there is a filter over one of the fans
> (what do you think that foam piece is covering?) Now are you going to tell
> me he's filtering the air LEAVING the computer? If so, that is WEIRD, and
> even so what is the point of that bizarre filter design? That leads me to
> believe that filter is filtering INPUT air. If so, then are you saying the
> PSU blows air IN? I doubt it. Therefor, you've got a fan blowing in
> directly below the PSU fan blowing out. That's not a very good design. If
> this is not the case, then please explain, because if I'm wrong then that
> diagram is way too confusing.
>
>

Look at the third picture down where he's holding a cardboard template.
See the line drawn on the card that goes from between the two fans up?
That's a divider. The area below that is the intake for the bottom fan;
the area above is the exhaust for the PSU fan, the divider deflecting
the airflow upwards.

Now look at the next page, second picture, you can see the divider (the
photo is looking from underneath the duct), but it's not too clear as
he's covered it inside and out with soundproofing felt.

------+ |
| /|
| / |
PSU | / |
| / |
| / |
|/ |
| /|
| / |
IN FAN| / |
| / |
| / |
|/^ |
|
|
FILTER

Parish

 

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"Parish" <me@privacy.net> wrote in message
news:c51arm$2ofq7s$1@ID-206197.news.uni-berlin.de...
>
> Look at the third picture down where he's holding a cardboard template.
> See the line drawn on the card that goes from between the two fans up?
> That's a divider. The area below that is the intake for the bottom fan;
> the area above is the exhaust for the PSU fan, the divider deflecting
> the airflow upwards.

That's exactly what I said. I got flamed by Isaac Kuo who said I didn't get
it, and "They aren't next to each other. The intake is at the top rear. The
exhaust is at the front bottom." I don't know what Isaac is looking at, but
it doesn't seem to be what we're looking at. So I repeat what I said - it's
not a very good design. Just like you need a baffle for a loudspeaker
(don't set woofers sitting bare on your rear car deck), likewise you should
not be intake and exhaust fans right next to each other. They have a
tendency to cancel each other out and you get much reduced airflow over your
motherboard.

 

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Archived from groups: uk.comp.homebuilt,alt.comp.hardware.pc-homebuilt (More info?)

In article <40742917_1@news1.prserv.net>, "jeffc" nobody@nowhere.com
says...
>
> "Isaac Kuo" <mechdan@yahoo.com> wrote in message
> news:acc26c07.0404061146.78dc82e8@posting.google.com...
> >
> > If you don't get it, then please try reading the article
> > linked above. It explains everything, with plenty of
> > pictures.
> >
> > Sorry, I just didn't see the need to explain how bluefront's
> > case works seeing as he's already done an excellent job of
> > it in the above link.
>
> If it does what you say it does, then no, he hasn't. Look at the link
> again. In the rear of the case, there is a filter over one of the fans
> (what do you think that foam piece is covering?) Now are you going to tell
> me he's filtering the air LEAVING the computer? If so, that is WEIRD, and
> even so what is the point of that bizarre filter design? That leads me to
> believe that filter is filtering INPUT air. If so, then are you saying the
> PSU blows air IN? I doubt it. Therefor, you've got a fan blowing in
> directly below the PSU fan blowing out. That's not a very good design. If
> this is not the case, then please explain, because if I'm wrong then that
> diagram is way too confusing.
>
Air intake is via the aperture at the rear below the PSU - it is ducted
over the CPU heatsink, and then leaves the case either through the PSU
or through the filter box underneath. This is a departure from standard
practice because the inside of the case is at reduced pressure, and some
of the exhaust is via the bottom front of the case. So it goes against
convection within the case, and the air box and PSU are fighting each
other for air. I reckon it's an ill-conceived design, but it's quite
possible that it keeps everything cool and quiet. I wouldn't do it that
way though.

 

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Archived from groups: uk.comp.homebuilt,alt.comp.hardware.pc-homebuilt (More info?)

Rob Morley <nospam@ntlworld.com> wrote in message news:<MPG.1ade48318475a6b4989853@news.individual.net>...

> Air intake is via the aperture at the rear below the PSU - it is ducted
> over the CPU heatsink, and then leaves the case either through the PSU
> or through the filter box underneath. This is a departure from standard
> practice because the inside of the case is at reduced pressure, and some
> of the exhaust is via the bottom front of the case. So it goes against
> convection within the case, and the air box and PSU are fighting each
> other for air.

Another way to look at it is that the air box and the PSU are
working with each other to pull air through the CPU heatsink.
Thus, the CPU receives the maximum amount of airflow, as well
as the freshest, coolest, air. In modern computers, this
makes sense since the CPU generates so much more heat and
require so much more cooling, while PSU cooling requirements
haven't really changed.

> I reckon it's an ill-conceived design, but it's quite
> possible that it keeps everything cool and quiet. I wouldn't do it that
> way though.

Bluefront's latest design is a less extreme mod featuring
the bottom filter as air intake rather than exhaust.

Still, the importance of upward convection force is vastly
overrated, IMHO. Any fan, even a very slow turning
silent 120mm, will overwhelm the miniscule convection force
unless the case is running VERY hot.

My HTPC relies entirely on one slow moving thermistor
controlled PSU fan, pulling air downward from the only
intake at the top to the only exhaust at the bottom.
This machine runs pretty cool, so convection force is
negligible.

Isaac Kuo

 

[Guest]

Archived from groups: uk.comp.homebuilt,alt.comp.hardware.pc-homebuilt (More info?)

jeffc wrote:

> "Parish" <me@privacy.net> wrote in message
> news:c51arm$2ofq7s$1@ID-206197.news.uni-berlin.de...
>>
>> Look at the third picture down where he's holding a cardboard template.
>> See the line drawn on the card that goes from between the two fans up?
>> That's a divider. The area below that is the intake for the bottom fan;
>> the area above is the exhaust for the PSU fan, the divider deflecting
>> the airflow upwards.
>
> That's exactly what I said. I got flamed by Isaac Kuo who said I didn't get
> it, and "They aren't next to each other. The intake is at the top rear. The
> exhaust is at the front bottom." I don't know what Isaac is looking at, but
> it doesn't seem to be what we're looking at. So I repeat what I said - it's
> not a very good design. Just like you need a baffle for a loudspeaker
> (don't set woofers sitting bare on your rear car deck), likewise you should
> not be intake and exhaust fans right next to each other. They have a
> tendency to cancel each other out and you get much reduced airflow over your
> motherboard.
>
>

Ah right, I went back and re-read Isaac's post and I see what you mean.
There _is_ an exhaust in the bottom of the case (in the wooden plinth
it's sat on) _as well as_ the PSU exhaust. This is what Rob Morley meant
when he said they (the base and the PSU exhausts) were fighting each other.

The base exhaust is detailed in part three of the article,
http://www.silentpcreview.com/article108-page1.html

Regards,

Parish

 

[Guest]

Archived from groups: uk.comp.homebuilt,alt.comp.hardware.pc-homebuilt (More info?)

"Parish" <me@privacy.net> wrote in message
news:c51nfj$2neb6c$1@ID-206197.news.uni-berlin.de...
>
> Ah right, I went back and re-read Isaac's post and I see what you mean.
> There _is_ an exhaust in the bottom of the case (in the wooden plinth
> it's sat on) _as well as_ the PSU exhaust. This is what Rob Morley meant
> when he said they (the base and the PSU exhausts) were fighting each
other.
>
> The base exhaust is detailed in part three of the article,
> http://www.silentpcreview.com/article108-page1.html

Ah, I see. Well, that does make it more interesting. Hmmm....

 

[Guest]

Archived from groups: uk.comp.homebuilt,alt.comp.hardware.pc-homebuilt (More info?)

In article <acc26c07.0404071310.59f9a4b1@posting.google.com>, "Isaac
Kuo" mechdan@yahoo.com says...
> Rob Morley <nospam@ntlworld.com> wrote in message news:<MPG.1ade48318475a6b4989853@news.individual.net>...
>
> > Air intake is via the aperture at the rear below the PSU - it is ducted
> > over the CPU heatsink, and then leaves the case either through the PSU
> > or through the filter box underneath. This is a departure from standard
> > practice because the inside of the case is at reduced pressure, and some
> > of the exhaust is via the bottom front of the case. So it goes against
> > convection within the case, and the air box and PSU are fighting each
> > other for air.
>
> Another way to look at it is that the air box and the PSU are
> working with each other to pull air through the CPU heatsink.
> Thus, the CPU receives the maximum amount of airflow, as well
> as the freshest, coolest, air. In modern computers, this
> makes sense since the CPU generates so much more heat and
> require so much more cooling, while PSU cooling requirements
> haven't really changed.

I don't have a problem with giving the CPU fresh air, but I'm not keen
on the negative pressure setup.

> > I reckon it's an ill-conceived design, but it's quite
> > possible that it keeps everything cool and quiet. I wouldn't do it that
> > way though.
>
> Bluefront's latest design is a less extreme mod featuring
> the bottom filter as air intake rather than exhaust.
>
Why do it any other way? Filtration and muffling combined, no need for
bits sticking out the back, intake at floor level where it's likely
cooler. So you need to do a bit more engineering to duct the CPU, but I
still reckon it's the obvious way to do it.

> Still, the importance of upward convection force is vastly
> overrated, IMHO. Any fan, even a very slow turning
> silent 120mm, will overwhelm the miniscule convection force
> unless the case is running VERY hot.
>
> My HTPC relies entirely on one slow moving thermistor
> controlled PSU fan, pulling air downward from the only
> intake at the top to the only exhaust at the bottom.
> This machine runs pretty cool, so convection force is
> negligible.
>
It just seems odd to me to go against the flow, even though it's
relatively small.

 

[louise]

Archived from groups: uk.comp.homebuilt,alt.comp.hardware.pc-homebuilt (More info?)

In article <4071CD4C.508786FE@lauragoodwin.org>, laura@lauragoodwin.org
says...
> Dorothy Bradbury wrote:
> >
> > > in a house that gets dusty (it's being restored)
> >
> > So industrial environment - continual brick/wood/cement dust
>
> Perhaps an ionizer in your PC room would help? I have one, and they
> clean the air silently. It's not just good for the PC, it's good for
> you.
>

What kind do you use?

Louise