Case fans question...

G

Guest

Guest
Archived from groups: alt.comp.periphs.mainboard.asus (More info?)

I have three questions regarding case fans even though I know that this is
an Asus newsgroup. Should the back case fan blow in air or blow out air?
Should the case fan in the side panel blow in air or blow out air? Should
the case fan on the top blow in or blow out? Help would be appreciated.
Thanks.
 
Archived from groups: alt.comp.periphs.mainboard.asus (More info?)

In article <72HBc.70875$Hg2.61444@attbi_s04>, "Travis King"
<anonymous@none.com> wrote:

> I have three questions regarding case fans even though I know that this is
> an Asus newsgroup. Should the back case fan blow in air or blow out air?
> Should the case fan in the side panel blow in air or blow out air? Should
> the case fan on the top blow in or blow out? Help would be appreciated.
> Thanks.

(Pg.26 has a section on the computer case)
http://www.amd.com/us-en/assets/content_type/white_papers_and_tech_docs/23794.pdf

Case air < 40C
Case air to room air difference less than 7C difference.
Air from lower front to upper back.
Power supply fan doesn't count as a fan (too slow).

Fans not associated with back to front, should do whatever is
best for the whole case. A CPU (side) fan should exhaust, to carry
the CPU air away from the case, and avoid mixing with the rest of the
case air. The assumption is, the CPU fan is responsible for
getting the heat transferred from the CPU heatsink to the air, and
any other fans can be used to carry the hot air away.

The analysis of using fans from multiple directions, blowing in and
out, is really complicated, and you have to be careful not to create
unintentional dead zones in the case, due to spoiling the simple
front to back airflow. For example, too many fans blowing in, from
all directions, might leave the disk drives in a dead zone. If the
back fan is stronger than the front fan, there will be negative
pressure around holes next to the disk drives, and help carry cool air
from front inlet vents, past the disks. If the front fan was much
stronger than the back fan, warm air could end up blowing out the front
of the case, heating the disk drives as it leaves.

The disks deserve the most attention, as they have the most to lose.
Anything else that overheats, will just crash, until it cools
off again.

And I'm still waiting for a credible theory as to what config
doesn't cause dust to build up 🙂

Paul
 
Archived from groups: alt.comp.periphs.mainboard.asus (More info?)

Front and side fans should pull the cooler air IN to the case. Back and top
fans should pull the hot air OUT of the case. If you don't have a front
case fan, then try to have the side panel fan approximately twice the cfm of
the other two combined. You want the input and output to be as close to
equal as possible.
Silvertip
"Travis King" <anonymous@none.com> wrote in message
news:72HBc.70875$Hg2.61444@attbi_s04...
> I have three questions regarding case fans even though I know that this is
> an Asus newsgroup. Should the back case fan blow in air or blow out air?
> Should the case fan in the side panel blow in air or blow out air? Should
> the case fan on the top blow in or blow out? Help would be appreciated.
> Thanks.
>
>
 
Archived from groups: alt.comp.periphs.mainboard.asus (More info?)

Case air flow is dependent on case design, motherboard layout in the case,
position of additional pci/apg cards, type of cooling on the cpu and video
card (fan, heatsink, water cooled), wire location, and wire configuration.
In general you want air to flow in at the bottom front of the case and out
the upper back of the case. Having said that, the blow hole in the top of
the case would move hot air out using natural convection forces (hot air
rises). Seeing that the fans in the back of the case are elevated in
comparison to the front of the case hot air would naturally exit the upper
back of the case, therefore the fans in the back of the case should exhaust
out hot air (blow air out of the case).

The issue of the side case fan blowing air into or out of the case depends
on the location of the fan. If the side case fan is located relatively
close to the cpu then the side case fan should blow air into the case. If
the side case fan is located above the cpu and relatively close to the power
supply it should blow air out of the case. In most of the cases I have seen
the side panel case fan is located relatively close to the cpu and therefore
should blow into the case providing cool fresh air to the cpu fan.

In relationship to a positive or negative pressure in the case, my
experience and testing lead me to believe that a positive case pressure is
better for two reasons. One, the positive pressure will prevent dust from
entering into the CD drives and covering the laser lens. Two, a positive
pressure keeps the heat build up around the power supply from entering into
the case around the cpu. A positive pressure means that you will have
higher cubic feet per minute fans blowing into the case than out of the
case.

The best way to setup case cooling is to use a fan contoller or manually
adjustable high speed variable fans (thermaltake smart fans, evermax fans)
especially at the front intake area of the case and buy a cheap
indoor/outdoor thermometer to monitor the temperature, adjust the fan speed
and watch the case temperature at various spots (esp around the cpu and hard
drives). Remember that more case fans does not lead to better cooling,
proper air flow though the case leads to better cooling. It also helps to
remove those stupid built in hole drilled case grills with a demel or tin
snips and use a wire grill in its place (if necessary).

If you think that this is long, you should see an engineering paper or
article discribing the effects of fan placement within a PC case. It is
very complicated and unpredictable. Try it, monitor it, and see if it works
for you.


"Travis King" <anonymous@none.com> wrote in message
news:72HBc.70875$Hg2.61444@attbi_s04...
> I have three questions regarding case fans even though I know that this is
> an Asus newsgroup. Should the back case fan blow in air or blow out air?
> Should the case fan in the side panel blow in air or blow out air? Should
> the case fan on the top blow in or blow out? Help would be appreciated.
> Thanks.
>
>
 
Archived from groups: alt.comp.periphs.mainboard.asus (More info?)

My computer has a case temperature sensor on the front of although I don't
know how good it is, and is also doesn't to Celsius; it does Fereignheit.
Keep in mind that my room doesn't have air-conditioning - it's running at
84.2. My room is in the basement. (I'm the 16-year old son.) I have the
Aspire X-Dreamer II case.
http://www.newegg.com/app/ViewProductDesc.asp?description=11-144-026&depa=0
FYI: My case came with the side panel fan and the top fan. Both of these
have the holes cut out already with alien grills. I also bought an aluminum
case fan with blue LEDs. I'm a little disappointed in it because it doesn't
have as much air flow as the rest of my fans do. I've also upgraded the PSU
to a 400w PSU with 2 fans. (I know the PSU fans to play much of a role)
I've got an Asus A7V333 motherboard, AMD Athlon XP 2400+ CPU, Kingston
PC-3000 DDR RAM, NVIDIA GeForce3 Ti200 128MB DDR TV Out, 200GB of total disk
space (2 WD's), etc. etc. My system is not water-cooled.
"Rusty" <rlsmith004@hotmail.com> wrote in message
news:9NqCc.124790$Gx4.8121@bgtnsc04-news.ops.worldnet.att.net...
> Case air flow is dependent on case design, motherboard layout in the case,
> position of additional pci/apg cards, type of cooling on the cpu and video
> card (fan, heatsink, water cooled), wire location, and wire configuration.
> In general you want air to flow in at the bottom front of the case and out
> the upper back of the case. Having said that, the blow hole in the top of
> the case would move hot air out using natural convection forces (hot air
> rises). Seeing that the fans in the back of the case are elevated in
> comparison to the front of the case hot air would naturally exit the upper
> back of the case, therefore the fans in the back of the case should
exhaust
> out hot air (blow air out of the case).
>
> The issue of the side case fan blowing air into or out of the case depends
> on the location of the fan. If the side case fan is located relatively
> close to the cpu then the side case fan should blow air into the case. If
> the side case fan is located above the cpu and relatively close to the
power
> supply it should blow air out of the case. In most of the cases I have
seen
> the side panel case fan is located relatively close to the cpu and
therefore
> should blow into the case providing cool fresh air to the cpu fan.
>
> In relationship to a positive or negative pressure in the case, my
> experience and testing lead me to believe that a positive case pressure is
> better for two reasons. One, the positive pressure will prevent dust from
> entering into the CD drives and covering the laser lens. Two, a positive
> pressure keeps the heat build up around the power supply from entering
into
> the case around the cpu. A positive pressure means that you will have
> higher cubic feet per minute fans blowing into the case than out of the
> case.
>
> The best way to setup case cooling is to use a fan contoller or manually
> adjustable high speed variable fans (thermaltake smart fans, evermax fans)
> especially at the front intake area of the case and buy a cheap
> indoor/outdoor thermometer to monitor the temperature, adjust the fan
speed
> and watch the case temperature at various spots (esp around the cpu and
hard
> drives). Remember that more case fans does not lead to better cooling,
> proper air flow though the case leads to better cooling. It also helps to
> remove those stupid built in hole drilled case grills with a demel or tin
> snips and use a wire grill in its place (if necessary).
>
> If you think that this is long, you should see an engineering paper or
> article discribing the effects of fan placement within a PC case. It is
> very complicated and unpredictable. Try it, monitor it, and see if it
works
> for you.
>
>
> "Travis King" <anonymous@none.com> wrote in message
> news:72HBc.70875$Hg2.61444@attbi_s04...
> > I have three questions regarding case fans even though I know that this
is
> > an Asus newsgroup. Should the back case fan blow in air or blow out
air?
> > Should the case fan in the side panel blow in air or blow out air?
Should
> > the case fan on the top blow in or blow out? Help would be appreciated.
> > Thanks.
> >
> >
>
>
 
Archived from groups: alt.comp.periphs.mainboard.asus (More info?)

After looking at the case, I would recommend that you place the highest air
flow fans in the lower front of the case you will have to remove the front
plastic covering. From the pictures it looks as if it has three plastic
hole snaps. If they are snaps, just slightly squeeze and push on the snaps
at the same time. You may have to use a screw driver to pry on it a little.
If it has screws just use a screw driver and remove the three screws from
each side.

Look at the amperage or wattage printed on the circular center of the fan
the highest amperage or wattage fan usually has the highest air flow. If
you look on the side of the fan there are general arrows which show the air
flow direction. If they don't have arrows the fan will move air from the
open side to the cage or fan support side.

Place the two front fans to move air into the case.
Place the side panel fan to move air into the case.
Have the two back fans move air out of the case.
Place the top blow hole fan to move air out of the case.

I believe that the temperature monitor on the front of the case can be set
to read °C by changing the jumpers on the LED from the back side of the
case. Check your case manual to see if this can be done. If not, the
formula to convert to °C is
(°F-32)/1.8 = ­°C

I live in the south and this time of year with AC on the temperature inside
the house runs about 80°F. I have found that for ever 1°C (2°F) increase in
the room temperature there is generally a 2°C (4°F) increase in the cpu
temperature. Check it out for your self, you can use the ASUS probe
software to monitor the cpu temperature and the built in case thermal senor
and compare the two at different room temperatures. Makes for a interesting
experment.

I believe that this will be the best air flow for your case. A good heat
sink (copper) would help lower the cpu temperature along with some artic 5
paste. Thermalright, Swiftech, and Thermaltake make some excellent cpu heat
sink products. (SLK900, MCX462, Volcano 12) Excellent case and system. Had
a GF3 Ti200 and recently bought a Evga GF 5900 SE made a big difference.
Excellent setup.

Abit NF7-S v2.0
AMD 1700+ at 1700Mhz from the default of 1467Mhz (core 680 version A)
FSB 170 Muliplier 10.0 default of FSB 133 Muliplier 11.0
Micron DDR 2100 at 170Mhz 3 3 3 11
Seagate 40 ATA100 (29°C)
cpu voltage 1.675v 31° C idle / 41°C load thermaltake slient boost with a
vantec volcano fan and reostat (4500rpm)
room temp 24.6°C (77°F)
room temp = 27°C (80°F) 34°C idle / 44°C load

I have two thermaltake smart fans and 2 sunon 0.14 amp fans on the front
intake.
One side case led intake fan 30cfm.
One top blow led exhaust fan 32cfm fan
Two back pctoys led exhaust fans both adjustable at approximately 42cfm.
Use a thermaltake 420w power supply with temperature controled fans.
The thermaltake power supply unit (PSU) fans gererally operate at 1300 -
1500 rpm.
The measured case temperature is generally about 1 - 1.5 °C above room temp.
My case is a modified design from an older power max case.
I used a old power max case because of the slotted vent across the top of
the case (hard to find).

hope this helps.

"Travis King" <anonymous@none.com> wrote in message
news😀GrCc.82034$Hg2.44819@attbi_s04...
> My computer has a case temperature sensor on the front of although I don't
> know how good it is, and is also doesn't to Celsius; it does Fereignheit.
> Keep in mind that my room doesn't have air-conditioning - it's running at
> 84.2. My room is in the basement. (I'm the 16-year old son.) I have the
> Aspire X-Dreamer II case.
>
http://www.newegg.com/app/ViewProductDesc.asp?description=11-144-026&depa=0
> FYI: My case came with the side panel fan and the top fan. Both of these
> have the holes cut out already with alien grills. I also bought an
aluminum
> case fan with blue LEDs. I'm a little disappointed in it because it
doesn't
> have as much air flow as the rest of my fans do. I've also upgraded the
PSU
> to a 400w PSU with 2 fans. (I know the PSU fans to play much of a role)
> I've got an Asus A7V333 motherboard, AMD Athlon XP 2400+ CPU, Kingston
> PC-3000 DDR RAM, NVIDIA GeForce3 Ti200 128MB DDR TV Out, 200GB of total
disk
> space (2 WD's), etc. etc. My system is not water-cooled.
> "Rusty" <rlsmith004@hotmail.com> wrote in message
> news:9NqCc.124790$Gx4.8121@bgtnsc04-news.ops.worldnet.att.net...
> > Case air flow is dependent on case design, motherboard layout in the
case,
> > position of additional pci/apg cards, type of cooling on the cpu and
video
> > card (fan, heatsink, water cooled), wire location, and wire
configuration.
> > In general you want air to flow in at the bottom front of the case and
out
> > the upper back of the case. Having said that, the blow hole in the top
of
> > the case would move hot air out using natural convection forces (hot air
> > rises). Seeing that the fans in the back of the case are elevated in
> > comparison to the front of the case hot air would naturally exit the
upper
> > back of the case, therefore the fans in the back of the case should
> exhaust
> > out hot air (blow air out of the case).
> >
> > The issue of the side case fan blowing air into or out of the case
depends
> > on the location of the fan. If the side case fan is located relatively
> > close to the cpu then the side case fan should blow air into the case.
If
> > the side case fan is located above the cpu and relatively close to the
> power
> > supply it should blow air out of the case. In most of the cases I have
> seen
> > the side panel case fan is located relatively close to the cpu and
> therefore
> > should blow into the case providing cool fresh air to the cpu fan.
> >
> > In relationship to a positive or negative pressure in the case, my
> > experience and testing lead me to believe that a positive case pressure
is
> > better for two reasons. One, the positive pressure will prevent dust
from
> > entering into the CD drives and covering the laser lens. Two, a
positive
> > pressure keeps the heat build up around the power supply from entering
> into
> > the case around the cpu. A positive pressure means that you will have
> > higher cubic feet per minute fans blowing into the case than out of the
> > case.
> >
> > The best way to setup case cooling is to use a fan contoller or manually
> > adjustable high speed variable fans (thermaltake smart fans, evermax
fans)
> > especially at the front intake area of the case and buy a cheap
> > indoor/outdoor thermometer to monitor the temperature, adjust the fan
> speed
> > and watch the case temperature at various spots (esp around the cpu and
> hard
> > drives). Remember that more case fans does not lead to better cooling,
> > proper air flow though the case leads to better cooling. It also helps
to
> > remove those stupid built in hole drilled case grills with a demel or
tin
> > snips and use a wire grill in its place (if necessary).
> >
> > If you think that this is long, you should see an engineering paper or
> > article discribing the effects of fan placement within a PC case. It is
> > very complicated and unpredictable. Try it, monitor it, and see if it
> works
> > for you.
> >
> >
> > "Travis King" <anonymous@none.com> wrote in message
> > news:72HBc.70875$Hg2.61444@attbi_s04...
> > > I have three questions regarding case fans even though I know that
this
> is
> > > an Asus newsgroup. Should the back case fan blow in air or blow out
> air?
> > > Should the case fan in the side panel blow in air or blow out air?
> Should
> > > the case fan on the top blow in or blow out? Help would be
appreciated.
> > > Thanks.
> > >
> > >
> >
> >
>
>
 
Archived from groups: alt.comp.periphs.mainboard.asus (More info?)

"Travis King" <anonymous@none.com> wrote in message news:<72HBc.70875$Hg2.61444@attbi_s04>...
> I have three questions regarding case fans even though I know that this is
> an Asus newsgroup. Should the back case fan blow in air or blow out air?
> Should the case fan in the side panel blow in air or blow out air? Should
> the case fan on the top blow in or blow out? Help would be appreciated.
> Thanks.

I have a Lian Li case with 2 multi-speed intake fans on the front of
the case near the bottom. 1 exhaust fan on the back and 1 exhaust fan
on the top. And since my computer is under a large desk, I have a
desktop fan behind my computer to stop any build up of hot air from
the power unit.

By the way, don't be tempted to put your finger in to a Pentium
3.06Ghz cooling fan to see if it is spinning. It'll take your finger
off.