Cpu coolers and side vents?

[Davej]

Well, I've never messed with aftermarket cpu coolers, but I've been
looking at them recently and it seems that there are two varieties --
the ones that blow across and the ones that blow down on the cpu.
Currently the "across" style seems to be ahead in the ratings -- but
to me the "blow down" scheme seems to make more sense for a tower case
with a side vent. Does anyone here have a case with a side vent which
couples directly up with the cpu cooler?

 

[Mike Easter]

Well, I've never messed with aftermarket cpu coolers, but I've been
looking at them recently and it seems that there are two varieties --
the ones that blow across and the ones that blow down on the cpu.
Currently the "across" style seems to be ahead in the ratings -- but
to me the "blow down" scheme seems to make more sense for a tower case
with a side vent. Does anyone here have a case with a side vent which
couples directly up with the cpu cooler?

I have a coolermaster case which is designed to have a shroud to direct
the cpu hotair out the side of the case (or coolair into the cpu fan),
but my case didn't include the shroud. I wrote CM about it, but they
never answered.

Here's the case open showing the shroud http://snipr.com/q7yc1 You
can't see the mobo/cpu location as the case is empty.

Here's the case closed showing the shroud's perforated side port
http://snipr.com/q802t

If you had a cpu fan directed down on/ toward/ the cpu, then coolair
would be coming into it from outside the case; if you had a cpu fan
directed away from the cpu, then cpuair would be going outside the case
via the shroud and sidepanel perforations.

 

[Davej]

[...]
I have a coolermaster case which is designed to have a shroud to direct
the cpu hotair out the side of the case (or coolair into the cpu fan),
but my case didn't include the shroud. I wrote CM about it, but they
never answered.

Here's the case open showing the shroudhttp://snipr.com/q7yc1 You
can't see the mobo/cpu location as the case is empty.

Yes, that is just what I was thinking of. I'm going to try to do that.

 

[Davej]

[...]
So when someone tells me they "have seven fans and it still
runs hot", then I have to ask whether those fans are working
against one another. Maybe only one of the fans has a good
net airflow, and all the other ones do is make a noise.

I used the "kleenex" test on a lower intake fan on one of my
cases, and found air was blowing through that fan backwards!

Well, I agree with that. Sounds like a good check.

Generally, you want a front to back airflow on an ATX case.
The idea there, is the hard drives get the coolest of the
airflow. Other components in the computer, can take a bit
more heat. But once you add additional fans, then unexpected
things can happen.

Yes, but just to confuse things my ATX power supply pulls air in the
back rather than exhausting it out the back. I understand that was the
ATX standard. I may open the supply up and reverse that fan. I like
the idea of room temperature air blowing on the cpu from a dedicated
side vent and I also like the front intake blowing air on the HD's.
The problem with rear exhaust is that so much of the back of the case
is restricted by the card slot area. Maybe mesh card slot fillers are
available?

In the case of hard drives, you can use SMART to read out the
hard drive temperature. For example, using HDTune 2.55, my two drives
are at 33C and 32C.

I may try that. Thanks.

 

[SteveH]

[...]
So when someone tells me they "have seven fans and it still
runs hot", then I have to ask whether those fans are working
against one another. Maybe only one of the fans has a good
net airflow, and all the other ones do is make a noise.

I used the "kleenex" test on a lower intake fan on one of my
cases, and found air was blowing through that fan backwards!

Well, I agree with that. Sounds like a good check.

Generally, you want a front to back airflow on an ATX case.
The idea there, is the hard drives get the coolest of the
airflow. Other components in the computer, can take a bit
more heat. But once you add additional fans, then unexpected
things can happen.

Yes, but just to confuse things my ATX power supply pulls air in the
back rather than exhausting it out the back. I understand that was the
ATX standard.

New one on me. I've lost count of the amount of PC's I've built and ATX
PSU's I've fitted and I've never come across a standard ATX PSU that sucks
air in from the back.

 

[Bob]

[...]
I have a coolermaster case which is designed to have a shroud to direct
the cpu hotair out the side of the case (or coolair into the cpu fan),
but my case didn't include the shroud. I wrote CM about it, but they
never answered.

Here's the case open showing the shroudhttp://snipr.com/q7yc1 You
can't see the mobo/cpu location as the case is empty.

Yes, that is just what I was thinking of. I'm going to try to do that.

I got that on a new computer I just bought and I had it on the old one that
just blew up Power supply took out almost everything.

You can, and I am, going to put a 3" fan in there (between the case and the
shroud, so it sucks air into the case and into the chip fan. I never had a
problem with that and I like the set-up.

Thanks,
Bob