For cooling, which is better - open case or sealed case with fans?

Assuming a tower case, which is going to keep all the hardware cooler,
the case open on both sides or a sealed case with a pusher on one end
and a big puller on the other?

Thanks for all input.

muzician21 wrote:

Assuming a tower case, which is going to keep all the hardware
cooler, the case open on both sides or a sealed case with a pusher
on one end and a big puller on the other?

Neither. There is no more compelling argument IMO for
positive/negative pressure in your case then the argument that you
do not want negative pressure working against your power supply fan.
The other issue, brought up not long ago, pointed out that tunneled
air can do more good than components in an open case with stagnant
air around them. Others might fill you in on the details of that
one. Also, I use a temperature and fan speed monitoring utility.
Knowing what is going on is very useful for getting it right.


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On Tue, 7 Apr 2009 16:26:36 -0700 (PDT), muzician21
wrote:

Assuming a tower case, which is going to keep all the hardware cooler,
the case open on both sides or a sealed case with a pusher on one end
and a big puller on the other?

Thanks for all input.


First I should say it doesn't necessarily matter which is
cooler, only that it is cool enough, at a desirable
compromise of fan noise, dust accumulation (even if it is a
filter cleaning interval), EMI escaping an open case, and
subjecting the parts to potential external stresses with the
case open such as children, pets, spilled drinks, etc. Thus
unless the system is very frequently fiddled with, parts
added or removed for example, keeping the side panels on is
a good goal.

A case with poor design may run cooler with the side panels
off. A case with reasonable design may run some parts
cooler and others warmer with the side panels off. A case
with good design will run some parts significantly cooler
with the side panels on and any that run hotter, do so to a
negligable extent as any part susceptible to overheating
should have heatsinks ample to keep them cool enough in a
properly designed ATX case, closed.

Perhaps a better way to put it would be that different
systems have different issues, one needs look at what the
temperatures are when the case is closed and if they are too
high, what the weak link is that caused the parts to exceed
the desired operationg temp range. Generally speaking if a
case has poor enough airflow that it runs cooler with the
side panels off, a better solution is to add another fan.

Since it can be burdensome to strip an entire system down so
that the parts in it aren't exposed to shards of metal
resulting from cutting a new fan hole, a common solution is
to take off the side panel and put the fan hole in it
instead, situating the fan either across from a particular
part that is running too hot if there is only one, or if the
entire system runs a bit higher than desired then place the
fan in the lower right quadrant of the system (when looking
at the left side) so this intake fan's air flows the
greatest length reasonably possible towards the exhaust
fans, cooling as many parts as possible along the longer air
path.

In other cases this is not necessary, if the front intake
fan is mounted on a grill with ample open area but the
system is still starving for air it tends to be from a front
bezel that lacks ample openings, so the bezel might be
removed and it's open area increased instead of adding a
side panel fan, or by doing both of these things it may
allow lower RPM, quieter fans.

"muzician21" wrote in message
...
Assuming a tower case, which is going to keep all the hardware cooler,
the case open on both sides or a sealed case with a pusher on one end
and a big puller on the other?

Thanks for all input.

Sealed case with fans. Temperature in case will be warmer, but airflow in
sealed case will keep individual components cooler, and THAT is what you
want. -Dave

A closed case with fans will keep the hardware cooler because air is forced through the case instead of relying on convection to keep things cool. My main computer has two exhaust fans and no pusher. I leave the front plastic cover off to reduce restriction of the air flow. My processor is currently running at 32 deg. C and the motherboard is 29 deg. C.

muzician21 wrote:

Assuming a tower case, which is going to keep all the hardware cooler,
the case open on both sides or a sealed case with a pusher on one end
and a big puller on the other?

Thanks for all input.

--
Mike Walsh

It depends on the design of the case, including fans and interior layout...

Old airplane engines were air-cooled by airflow over the cylinders that
simply stuck out in the breeze. Later, cowls were put over them to reduce
air drag. Some intelligent people discovered that a cowled engine also
stayed cooler, and that evolved into today's closely cowled engines in
almost all piston engine designs. However, those designs must be
deliberately designed to ensure cooling air to all the cylinders.

Likewise, an open case will likely adequately cool a low-power system.
However, in a higher power system, airflow through the case has to be
engineered to cool the motherboard chips ("Northbridge" and "Southbridge"),
graphics processor (GPU), and hard drives as well as the CPU. If you look
in a higher power system these days, you will find large finned heat sinks
on all these components. Good airflow over all these components is crucial,
and may be enhanced by a closed case with well-placed fans.


"Mike Walsh" wrote...

A closed case with fans will keep the hardware cooler because air is
forced through the case instead of relying on convection to keep things
cool. My main computer has two exhaust fans and no pusher. I leave the
front plastic cover off to reduce restriction of the air flow. My
processor is currently running at 32 deg. C and the motherboard is 29 deg.
C.

muzician21 wrote:

Assuming a tower case, which is going to keep all the hardware cooler,
the case open on both sides or a sealed case with a pusher on one end
and a big puller on the other?

JR Weiss wrote:

It depends on the design of the case, including fans and interior
layout...

Old airplane engines were air-cooled by airflow over the cylinders
that simply stuck out in the breeze. Later, cowls were put over
them to reduce air drag. Some intelligent people discovered that
a cowled engine also stayed cooler, and that evolved into today's
closely cowled engines in almost all piston engine designs.
However, those designs must be deliberately designed to ensure
cooling air to all the cylinders.

Likewise, an open case will likely adequately cool a low-power
system. However, in a higher power system, airflow through the
case has to be engineered to cool the motherboard chips
("Northbridge" and "Southbridge"), graphics processor (GPU), and
hard drives as well as the CPU. If you look in a higher power
system these days, you will find large finned heat sinks on all
these components. Good airflow over all these components is
crucial, and may be enhanced by a closed case with well-placed
fans.

Please do not top-post. Your answer belongs after (or intermixed
with) the quoted material to which you reply, after snipping all
irrelevant material. See the following links:

http://www.catb.org/~esr/faqs/smart-questions.html
http://www.caliburn.nl/topposting.html
http://www.netmeister.org/news/learn2quote.html
http://cfaj.freeshell.org/google/ (taming google)
http://members.fortunecity.com/nnqweb/ (newusers)

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[page]: http://cbfalconer.home.att.net
Try the download section.

"CBFalconer" wrote...

Please do not top-post. Your answer belongs after (or intermixed
with) the quoted material to which you reply, after snipping all
irrelevant material. See the following links:

Please do not tell me how to post. If someone top-posts, I will continue to
respond in the same way so there is less confusion in the thread.

Please do not try to play "net cop." If you don't like the way I post, then
killfile me.

blank nym wrote...

Please do not top-post. Your answer belongs after (or intermixed
with) the quoted material to which you reply, after snipping all
irrelevant material. See the following links:

Please do not tell me how to post. If someone top-posts, I will continue
to
respond in the same way so there is less confusion in the thread.

Please do not try to play "net cop." If you don't like the way I post,
then
killfile me.

So long-established Usenet convention is irrelevant to you?

Quit being so easily offended and calling people names because someone
took the time to point you in the right direction.

I'm not offended. I am fully aware that top-posting is as long-established
a convention as is bottom-posting. Both conventions predate the public
Internet by several years. Neither one has been officially established as
"proper" or "improper," except in the minds of a few self-appointed net
cops.

I started my first BBS in 1989, in a Desqview window with a 9600 bps modem.
Didn't find Windoze until '92 or the Internet 'til '93...

On-topic part: Didn't need any fancy cooling for the Z80 machine with dual
5" SSSD floppies, or the 286 machine with EMS expansion board. Desqview
"rocked" with 2 MB RAM (but installing all those DIPP chips was a pain)!


"John" wrote...
I agree . . . I've been using Usenet for 13 years and top posting use to be
the norm. Before that I used the BBS with DOS based mail readers and you had
to wait till the next day to get a reply. Then Netscape Navigator came out
and the
Internet killed the BBS's


On Thu, 9 Apr 2009 14:15:22 -0000, "JR Weiss" wrote:

I'm not offended. I am fully aware that top-posting is as long-established
a convention as is bottom-posting. Both conventions predate the public
Internet by several years. . .