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TonyM16
01-23-07, 05:42 AM
.. Hi my question is which orienatation would create more dust inside a PC, an intake fan or an outake(exhaust) fan. Not as straightforward as it seems.

Also if you could have two fans over your dual gpu setup and very hot running mcp chip would you have them as exhaust or in take. I think intake is more important here, but all I ever see is exhaust. I think intake becasue back in the day I used to put a house fan on the inside of my pc'c sometime and temps would drop by a huge amount.

Same time i don't want dust all over them , which is why I wanted to know who creates more dust. Cheers.

Capt. Picard
01-23-07, 05:44 AM
Good question. I haven't figured it out yet. I wanted to start a thread about this very question for some time now.

Xion X2
01-23-07, 06:07 AM
.. Hi my question is which orienatation would create more dust inside a PC, an intake fan or an outake(exhaust) fan. Not as straightforward as it seems.

Also if you could have two fans over your dual gpu setup and very hot running mcp chip would you have them as exhaust or in take. I think intake is more important here, but all I ever see is exhaust. I think intake becasue back in the day I used to put a house fan on the inside of my pc'c sometime and temps would drop by a huge amount.

Same time i don't want dust all over them , which is why I wanted to know who creates more dust. Cheers.

Intake creates far more dust inside your case. I had an 84cfm Sunon mounted on the front of my last one and it sucked in a ton of dust.

And the best way to cool your graphics cards and that hot MCP is with intake air.

TonyM16
01-23-07, 06:29 AM
Intake creates far more dust inside your case. I had an 84cfm Sunon mounted on the front of my last one and it sucked in a ton of dust.

And the best way to cool your graphics cards and that hot MCP is with intake air.

HI. So basically a choice between superior cooling or lots of dust?

However, if you have two intake fans directly on top of two gpus and mobo, in this situation , can we assume that the fans will actually keep the rig clean, by blowing away dust? Hmm, so what would be the better choice, if you wanted the least dust, but as much cooling as possible?
Cheers.

nekrosoft13
01-23-07, 07:43 AM
use a fan filter

Capt. Picard
01-23-07, 08:06 AM
For me the most important question is whether there is a difference in temperature between inblowing and outblowing.

Amuro
01-23-07, 08:38 AM
For me the most important question is whether there is a difference in temperature between inblowing and outblowing.
There is a difference for cooling videocards. The fans on video cards like the 8800 suck in air to cool the heatsink, so you'd better provide cool intake air by inblowing. Also inblowing helps cool your chipset.

Xion X2
01-23-07, 08:58 AM
If you're aircooling, you're going to get dust inside your case no matter what. I even get a little dust in mine from my RAM cooler, although it's the only intake fan I have installed.

But if you use filters like slawter suggested it'll cut down on a lot of it. What kind of case do you have, Tony?

Roadhog
01-23-07, 10:27 AM
negative pressure inside your case will create less dust. so more exhaust cfm.

TonyM16
01-23-07, 10:49 AM
If you're aircooling, you're going to get dust inside your case no matter what. I even get a little dust in mine from my RAM cooler, although it's the only intake fan I have installed.

But if you use filters like slawter suggested it'll cut down on a lot of it. What kind of case do you have, Tony?

I used to have a Temjin, but it got old and knackered and the screw holes became the size of the gap in the ozone layer and so screws would no longer work lol. This meant my gpu's would have nothing to hold them in place.

So I have now just bought a CM Stacker 830 (black GP revision). As you already know it has plenty of places to put fans. The ones on the side panel intrigue me the most. Looking at it, it does have soem kind of a plastic mesh, but I don't know if that would be a dust filter or not. I think thats what it's for. SO I should be okay with two intakes on the bottom right? I am gonna be using those 120mm Akasa Amber fans as they are quiet but efficient (don't know why since they are so average looking?) > I am also gonn place an exhaust fan on the top of the stacker.

The stacker already comes with two fans an inatke and exhaust. I am not sure if it's worth replacing them. I do have enough Akasa to replace them all, but I don't know if it's worth it. The front one alos has a blue led. I may just hook them up to my fan controller using a 3pin to 4 pin lead, so I can keep their noise down.

I haven't tested the stock fans yet, does anyone know if they are good and quiet?

Thank you to everybody here, for answering my question. Really cool :afro:

Ohh by the way, RoadHog, can you explain about this negative pressure thing please? Are you saying that if all fans are intake I can create negative pressure? And so have loads less dust?

Xion X2
01-23-07, 10:59 AM
Well, you have the perfect case for air cooling, then. And yeah, the mesh will act as a dust filter. That's what it's there for.

Stock case fans usually suck, so you may want to look into replacing them. Either that or look the model fan up on newegg or some such site and get the specs on it first.

And roadhog was saying use more exhaust fans than intake fans so that you're exhausting more dust out of the case than you're sucking in. That's kind of hard to do with the stacker because of those side fans but he has a good point. Put you a strong exhaust fan on the back to shoot a lot of the dust out. You may also want to invest in one of those air dusters.. you know, the cold compressed air can thingy. I use that to spray all the dust out of my case often.

hirantha
01-23-07, 11:05 AM
no one can beat my air cooling temp. check it out in my sig :p

TonyM16
01-23-07, 11:18 AM
no one can beat my air cooling temp. check it out in my sig :p

You have the snail case don't you lol. That was a very nice looking case. So what's you secret other than the case and Zalman (didn't know the 9700 was that good, although I assume it's more to do with your case aswell)? Are you using those Delta fans or something. Is your PC really really loud or something, with loads of crazy fast fans?

Thanks Xion X2. Great advice, I am gonna have to test my stock fans , hopefully they will be able to push out more air than the Akasa so that I can create the correct pressure. Although it may work with All the Akasa's if somehow stop the hard drive fan from interfering with the rest of teh case, or maybe put one more exhaust on the side panel , on top of my heat sink, but I don't think that will be a good idea (I think that would create an air short circuit).

hirantha
01-23-07, 11:23 AM
You have the snail case don't you lol. That was a very nice looking case. So what's you secret other than the case and Zalman (didn't know the 9700 was that good, although I assume it's more to do with your case aswell)? Are you using those Delta fans or something. Is your PC really really loud or something, with loads of crazy fast fans?

hahah i never thought anyone would ask what the secret is, i have only 1 in and 1 out fan

tell you the truth my comp is right near the window hahaha dont laugh so i keep the window open and winter air sure cools it off. :D . in the summer it will be a total diff story.:p

nekrosoft13
01-23-07, 11:57 AM
hahah i never thought anyone would ask what the secret is, i have only 1 in and 1 out fan

tell you the truth my comp is right near the window hahaha dont laugh so i keep the window open and winter air sure cools it off. :D . in the summer it will be a total diff story.:p

thats cheating, leave the window open in summer too,

hirantha
01-23-07, 12:09 PM
thats cheating, leave the window open in summer too,
haha yeah i feel like cheating sorry yall... in the summer hopefully my AC would still work :D

Camp0rz
01-23-07, 07:02 PM
At night.. I bet I could get mine temps into the low twenties. God, I hate northern IL weather.


I'd try to set up a little intake from outside if I wasn't so lazy.

Amuro
01-23-07, 10:57 PM
Go ahead and take advantage of that side fan bracket of yours. I have 4 120mm fans installed on the side of my 830, blowing in, and they dropped my chipset/system temp by 10C, was idling at 40-41C without the fans. The 680i is just too hot with Asus' passive cooling. CPU idling at 18-19C stock speed /w the Freezer 7. Aslo helps cooling the memory so I don't even have to use the Corsair airflow fan, which might interfere with one of the video cards if installed.

Slammin
01-24-07, 02:44 AM
The direction of the fans depend a lot on where the fan is too. Top fans are usually better exhausting since heat rises and bottom fans are usually better sucking air into the case.

This doesn't always equal the best temps though because your gpu and/or cooler could come into play and then the best thing to do is experiment and see which direction gives you the best temps and airflow.

As mentioned, positive case pressure setups tend to create less dust in the case, but they also tend to create more hotspots in the case. You can create positive case pressure by say, having two intake and only one exhaust fan. The reason this creates less dust than negative case pressure setup is because the primary path air/dust gets into the case in positive pressure is the two fans. In negative pressure where you have more exhaust than intake, the case will 'leak' air/dust via whatever opening that isn't sealed (usb ports, mic ports, etc) into the case, but if you could somehow seal everything so that the only path in would be the fan, it would be excellent because you could just filter that, but good luck sealing a case that well!

Filters and canned air. There is no substitute :D

Roadhog
01-24-07, 10:28 AM
The direction of the fans depend a lot on where the fan is too. Top fans are usually better exhausting since heat rises and bottom fans are usually better sucking air into the case.

This doesn't always equal the best temps though because your gpu and/or cooler could come into play and then the best thing to do is experiment and see which direction gives you the best temps and airflow.

As mentioned, positive case pressure setups tend to create less dust in the case, but they also tend to create more hotspots in the case. You can create positive case pressure by say, having two intake and only one exhaust fan. The reason this creates less dust than negative case pressure setup is because the primary path air/dust gets into the case in positive pressure is the two fans. In negative pressure where you have more exhaust than intake, the case will 'leak' air/dust via whatever opening that isn't sealed (usb ports, mic ports, etc) into the case, but if you could somehow seal everything so that the only path in would be the fan, it would be excellent because you could just filter that, but good luck sealing a case that well!

Filters and canned air. There is no substitute :D

negative will have less dust...

Slammin
01-24-07, 11:31 PM
negative will have less dust...


Technically, you are correct, but cleaning an Antec P-160 that's been running 24/7 for weeks in a carpetted room, under negative case pressure....

Well, trust me, it is pretty difficult to clean because it has a series of vent holes all around the front bezel and it aint easy keeping those holes clear.

I finally just reversed a couple of fans and added filters and don't have that problem anymore.

Roadhog
01-24-07, 11:48 PM
Technically, you are correct, but cleaning an Antec P-160 that's been running 24/7 for weeks in a carpetted room, under negative case pressure....

Well, trust me, it is pretty difficult to clean because it has a series of vent holes all around the front bezel and it aint easy keeping those holes clear.

I finally just reversed a couple of fans and added filters and don't have that problem anymore.


Never said anything about cleaning. But I bet that is a pain to clean lol. :headexplode:

Rytr
01-24-07, 11:51 PM
negative pressure inside your case will create less dust. so more exhaust cfm.

Don't you mean positive pressure?
Positive pressure (more air coming in) inside the case tends to keep air from coming in every crack/opening in your case as the pressure will tend to blow air out these cracks/openings. Negative pressure tends to pull air in from everywhere. With a slight imbalance toward a positive pressure you can filter your intake fans and cut down the dust considerably.
Use to have to do this back in the days of overclocking the T-Birds to keep good airflow supplied to the 60mm Delta screamers cooling the sink on the CPU. Good air flow through the case was imperative to getting a 1GHz T'Bird to run 1.6-1.7GHz on air...or a 600/650 Duron to run 1GHz.
Not always an exact science because I did have one Enlight case that cooled better with negative pressure in favor of 15-20CFM to the exhaust fans. :)

Roadhog
01-24-07, 11:53 PM
Don't you mean positive pressure?
Positive pressure (more air coming in) inside the case tends to keep air from coming in every crack/opening in your case as the pressure will tend to blow air out these cracks/openings. Negative pressure tends to pull air in from everywhere. With a slight imbalance toward a positive pressure you can filter your intake fans and cut down the dust considerably.
Use to have to do this back in the days of overclocking the T-Birds to keep good airflow supplied to the 60mm Delta screamers cooling the sink on the CPU. Good air flow through the case was imperative to getting a 1GHz T'Bird to run 1.6-1.7GHz on air...or a 600/650 Duron to run 1GHz.
Not always an exact science because I did have one Enlight case that cooled better with negative pressure in favor of 15-20CFM to the exhaust fans. :)

Dust wont settle as easy if you have more exhaust (negative pressure) than intake.

Amuro
01-25-07, 04:04 AM
Dust wont settle as easy if you have more exhaust (negative pressure) than intake.
Oh really? I had a Dell Dimension with one exhaust and zero intake, and that thing was dust collector.