Better Air Flow?

Sorry to but in - i'm having a little cooling problem myself and to read that a roof blowhole should suck air into case rather than blow air out suprises me; i have 2x80mm at front, 70mm side fan sucking air in, 2x80mm sucking air out at back and a 120mm roof fan sucking air out.

Everyone has always said that roof blowhole should suck air out - are you all really saying that it should suck air into case?
 
I agree, more in than out. I have currently set up:
2 80MM - Lower Front - Sucking in
1 80MM - Side (around Ram and Chipset) - sucking in
1 80MM - Upper Rear - Blowing out
1 80MM - on heatsink, blowing Air toward upper Rear Fan
120 MM - PSU fan

This is the best configuration I have ever had and my case temps are around 28C, wheras ive had them at 35C when i've had more exaust than intakes.
 
malccy said:
Sorry to but in - i'm having a little cooling problem myself and to read that a roof blowhole should suck air into case rather than blow air out suprises me; i have 2x80mm at front, 70mm side fan sucking air in, 2x80mm sucking air out at back and a 120mm roof fan sucking air out.

Everyone has always said that roof blowhole should suck air out - are you all really saying that it should suck air into case?
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No worries, read again:

"I think that a hole pulling air in the top of the case may be a little counter productive to the airflow"

followed by:

"A slow blowhole fan on the top is great for getting the hot air out (as hot air rises) and could well aid in the cooling quite a bit just as long as it doesn't remove that postive bias."

Top Blowhole should 'gently' move the air out of the case.
 
SteveOBHave said:
No worries, read again:

"I think that a hole pulling air in the top of the case may be a little counter productive to the airflow"

followed by:

"A slow blowhole fan on the top is great for getting the hot air out (as hot air rises) and could well aid in the cooling quite a bit just as long as it doesn't remove that postive bias."

Top Blowhole should 'gently' move the air out of the case.
Click to expand...
Like i said earlier, i spent a week running thru every possible configeration and at the end of the day the fans running as mentioned worked best.
I know its strange that i have a 120mm blowing air down but cos of the positive air pressure, the warm air is forced out of the nearest gap via the easiest route, surely that is good airflow.
The top mounted 120mm blows air down over my Memory and mobo.
The missus has my digi camera at the mo but once i get it back i'l post a pic of my fan setup with a few arrows added in to show airflow etc.

images461New2 (Large).JPG


This one shows the front, side and roof 120mm fans as well as the vents and rear 2x80mm blowing out.
 
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Vegeta said:
I realise the PSU is pushing air out - but i've checked and it barely pushes anything out, so will it still be ok?
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Yeah, should be fine. Might be worth checking to make sure all the fans are running.

In the long run, it all comes down to the internal temps, ie - CPU GPU and if relevant Northbridge/NF chipsets. You're only going to run into issues if you are overclocking and/or if you are exceeding component operating temps.
 
pegasus1 said:
Like i said earlier, i spent a week running thru every possible configeration and at the end of the day the fans running as mentioned worked best.
I know its strange that i have a 120mm blowing air down but cos of the positive air pressure, the warm air is forced out of the nearest gap via the easiest route, surely that is good airflow.
The top mounted 120mm blows air down over my Memory and mobo.
The missus has my digi camera at the mo but once i get it back i'l post a pic of my fan setup with a few arrows added in to show airflow etc.

This one shows the front, side and roof 120mm fans as well as the vents and rear 2x80mm blowing out.
Click to expand...

WOW, nice looking Rig Pegasus. It's not strange at all to have a fan blowing down. Infact I am sure you will find most rigs that have a top blowhole are set up in that manner. It is that it could be counter productive to airflow in a case. The done thing seems to be to have a top blowhole sucking air in even if it may not be best.

End of the day tho, you can't argue with the numbers and if that works best for you, I'm not going to argue with you! Memory, contrary to popular belief doesn't actually get hot enough to warrant heatsinks, but if it is mounted close to hot components it may well be worth having decent airflow over that area.
 
I ment for the fan to blow air out of the top, however would it be ok just to have a grill at the top to allow the hot air out of the top of the case.

Since I have 3 fans blowing in and only the PSU and 1 fan blowing out. If I make a hole in the top wouldn't the positive air pressure inside the case push the hot air out of the top of the case even without the fan?

Jim
 
JimJones said:
I ment for the fan to blow air out of the top, however would it be ok just to have a grill at the top to allow the hot air out of the top of the case.

Since I have 3 fans blowing in and only the PSU and 1 fan blowing out. If I make a hole in the top wouldn't the positive air pressure inside the case push the hot air out of the top of the case even without the fan?

Jim
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I don't see why not. "Suck it and see"

Try it out and run some temp tests. Put a book over the hole and run them again. See if there is a difference.

The important thing is to have enough airflow over the vital components. ie. CPU, GPU and chipset heatsinks/fans.
 
A good point just have to dig out the old dreml maybe best to get a circler drill bit. Anyone have any tips for drilling holes in my case. After a little more thinking (twice in one life time, when your hot your hot :D) I was thinking about putting a 120mm fan on the bottom of my case to blow air up towards athe hole at the top of the case. I'd need to find a 120mm fillter grill thing as my floor isn't the cleanest thing :) Good or bad idea?

Jim
 
Lol - fan maniac :)

Prolly a bad idea - sucking up lots of dust I'd imagine. Generally the best airflow is up and diagonally across the Mobo. Altho with the size of the VGA cards these days it is getting harder to maintain clean airflow.

A large number of cases have front to back airflow, which is what I am going to be aiming for with my next case.

Good luck :)
 
JimJones said:
Anyone have any tips for drilling holes in my case.
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1. Mark the area where you want to drill the holes with a pencil or a perm marker.

2. Using a hammer and a large nail, tap a small indent into the point you want to drill. (helps guide the centre of the drill bit)

3. Drill!

4. Use a larger drill bit or something like the dremel cone shaped bit to clean the swarf off both sides of the hole.

The basic thing to get a tidy job, spend the time on the prep and don't rush it, and kiddies, ask for your parents help :)

NB: if it is cutting a blowhole you want to do, check out this link...


Hope this helps!
http://www.overclockersclub.com/guides/blowhole.php
 
Thanks for the guide.

I did think of having all the fans as intakes and giving it a skirt at the bottom for a hover case look :) or maybe getting some tubing and putting it over the CPU to make a wind tunnel with a fan at the top and the bottom of the tube. This would, I hope, make the case cooler since the CPU heat is taken out of the case. Only problem with this is the crappy lloking tube and the disruption of the air flow across the rest of the case.

Jim
 
I was thinking of putting in an "air tube". I have 4 optical drive bays on my case but only use one so i was thinking of mounting a 120mm fan in the space of the bottom 3 bays and making an acrylic tunnel with the fan sealed at the front and the tunnel leading to the CPU.

What im not sure of is whether it would be best to to have the tube end at the heatsink or to have the tube cover the heatsink and continue to an extraction fan mounted on the top or back of the case. In theory a tube running all the way through with 2 fans sounds better but i dont know if the heat could get traped near the heatsink (dont think it would with two 120mm fans push/pulling as long as i keep the tubing smooth with no sharp angles).
 
Yeah, it's a sticky one and I can't speak from experience on the tubing thing. My guess would be that it is more desirable to pipe the cool air to the fan on the heatsink or to the heatsink itself.

Personally I don't think that I'd remove the heatsink fan as they are generally designed to pass the air over the component heatsink in a specific way. Removing the heatsink fan and just attaching a piece of ducting to it may actually produce less efficient cooling results.

As for having an extraction tube, maybe. Personally I'd let the case evacuate the air itself as every little bit of extra air in the case helps. I think you are getting into a grey area as far as airflow and efficiency goes. Have a go and do some testing!

I found this example of a CPU ducting set up that seems to have a positive effect.

http://www.overclockers.com.au/article.php?id=147356

In my opinion, the aim should be to supply the attached cooling system with cooler air so that it can do it's job more efficiently.

After doing a bit of a google search, it seem Thermaltake do a slightly sketchy looking ducting mod, and I also found this one... looks ugly as sin tho... http://www.xpcgear.com/ockit.html
 
Another good find. I don't think I'm that adventurous to make a duct out of plastic I was just going to get some of that white tubing. I might get a small bit and attach it to my side case fan that migh help. Then I could just direct the air.

Jim
 
Will check out the links in a second. I was going to go for a scyth ninja HS which doesnt have a fan attached to it and is designed to have air blown onto it from the side. I guess putting an 8cm in the ducting just before the the HS wouldnt hurt.
 
Kind of what i had in mind (but i would do the job properly :) ) would have mine going from the front of the case to the HS. Thinking about it (and looking at the space in there) i dont think a tube going all the way through would be needed as the 12cm fan pulling the hot air out is right near the HS anyway. Think i will make a mock up one with cardboard tubing and see what the airflow is like.
 
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