corsair obsidian 750 Corsair Obsidian 750D - Airflow Edition Fan Setup?

[RoKa]

Hey guys,

Im planning on buying the  Corsair Obsidian 750D airflow edition. And I was wondering what setup is best to use. I was thinking about 2 intakes on the top and front and 1 in the back. To create possitive pressure and force more dust out.

But on every setup ive seen it was 2 intakes at the front and 2 outtakes at the top and 1 at the back.

Example of the 2nd case: 

Spoiler

So can someone please tell me the pros and cons of what im thinking?

Thanks in advance!

Kind Regards,

Roman

[Goodman2265]

That forces more dust in.

[Goodman2265]

Use the one in picture thats a balanced setup

[RoKa]

Just now, Goodman2265 said:

That forces more dust in.

The one on the picture or what Im talking of? I mean the case has an awesome magnetic filter ontop.

[Goodman2265]

Just now, RoKa said:

The one on the picture or what Im talking of? I mean the case has an awesome magnetic filter ontop.

What your talking about. Use the setup in the picture

[RoKa]

1 minute ago, Goodman2265 said:

What your talking about. Use the setup in the picture

I thought positive air pressure forced more dust out of the case.

[Goodman2265]

Just now, RoKa said:

I thought positive air pressure forced more dust out of the case.

The more intake the more dust. Its simple your bringing more air in. Hot air also expands so you wanna get rid of the hot air more effectively so you can bring new cool air in.

[RoKa]

2 minutes ago, Goodman2265 said:

The more intake the more dust. Its simple your bringing more air in. Hot air also expands so you wanna get rid of the hot air more effectively so you can bring new cool air in.

But bringing in air from the top and front both goes through a filter and that fresh new air pushes out the existing hot air which also gets pulled out by one fan at the back.

[afyeung]

2 minutes ago, Goodman2265 said:

The more intake the more dust. Its simple your bringing more air in. Hot air also expands so you wanna get rid of the hot air more effectively so you can bring new cool air in.

You're actually wrong for the most part except for your comment about hot air http://forums.anandtech.com/showthread.php?t=705389 negative pressure creates a vacuum affect so you bring in more unfiltered air. 

[ThatCarlosGuy]

More air coming in takes in more dust, yes. However, if you have your intakes filtered it will filter the dust out. So if you have positive pressure by have more airflow through filters on the intakes and less airflow as exhaust, you will keep dust down because the 'excess' air that the exhaust fans can't move will go out of any gaps.

But back on topic. For that case, I would just have the two intake fans on the front and one rear.

If you wanted to stay true to the image you posted, the two on the front should be made to run at a slightly higher rpm than the exaust. This will maintain positive pressure in your case

[Goodman2265]

Just now, RoKa said:

But bringing in air from the top and front both goes through a filter and that fresh new air pushes out the existing hot air which also gets pulled out by one fan at the back.

You asked for our opinions and you're not taking them in. I'm trying to help you. Negative air flow remove hot pockets in you're system. There is going to be dust anyway. Its impossible to not have dust. I recommend you read this http://www.tomshardware.com/forum/238184-31-case-airflow-positive-negative-pressure

[RoKa]

1 minute ago, ThatCarlosGuy said:

More air coming in takes in more dust, yes. However, if you have your intakes filtered it will filter the dust out. So if you have positive pressure by have more airflow through filters on the intakes and less airflow as exhaust, you will keep dust down because the 'excess' air that the exhaust fans can't move will go out of any gaps.

But back on topic. For that case, I would just have the two intake fans on the front and one rear.

If you wanted to stay true to the image you posted, the two on the front should be made to run at a slightly higher rpm than the exaust. This will maintain positive pressure in your case

Yeah I was trying to explain that I wanted to change what's in the picture. To make the top exhaust into a intake, because this case has a sexy magnetic filter there.

Im really doubting my English atm because I don't have the feeling people understand my initial post.

 

PS: I'm Dutch.

[ThatCarlosGuy]

1 minute ago, Goodman2265 said:

There is going to be dust anyway. Its impossible to not have dust.

There will always be dust, but there will be considerably LESS dust.

[RoKa]

2 minutes ago, Goodman2265 said:

You asked for our opinions and you're not taking them in. I'm trying to help you. Negative air flow remove hot pockets in you're system. There is going to be dust anyway. Its impossible to not have dust. I recommend you read this http://www.tomshardware.com/forum/238184-31-case-airflow-positive-negative-pressure

Im trying to create positive pressure by turning around the fans in the picture at the top of the case.

Quote

Yeah I was trying to explain that I wanted to change what's in the picture. To make the top exhaust into a intake, because this case has a sexy magnetic filter there.

Im really doubting my English atm because I don't have the feeling people understand my initial post. 

 

PS: I'm Dutch.

 

[ThatCarlosGuy]

1 minute ago, RoKa said:

Yeah I was trying to explain that I wanted to change what's in the picture. To make the top exhaust into a intake, because this case has a sexy magnetic filter there.

Im really doubting my English atm because I don't have the feeling people understand my initial post.

 

PS: I'm Dutch.

Oh i see. Well, gerenally hot air rises and cool air moves in its place. If you put intakes on the top, any heat that rises will get forced back down to your components. The dust filter at the top is mainly for stopping dust falling into your system. Generally, intakes on top is a big 'no-no'

[RoKa]

8 minutes ago, ThatCarlosGuy said:

Oh i see. Well, gerenally hot air rises and cool air moves in its place. If you put intakes on the top, any heat that rises will get forced back down to your components. The dust filter at the top is mainly for stopping dust falling into your system. Generally, intakes on top is a big 'no-no'

Ah ok, just one more thing to take into consideration.

If you force air from the top and the front. Doesnt the front intakes push the hot air out?

Epic drawn picture explaining what Im thinking:

Spoiler

Edit: Omfg the forum makes the picture appearing 10x cooler

[RoKa]

13 minutes ago, ThatCarlosGuy said:

Oh i see. Well, gerenally hot air rises and cool air moves in its place. If you put intakes on the top, any heat that rises will get forced back down to your components. The dust filter at the top is mainly for stopping dust falling into your system. Generally, intakes on top is a big 'no-no'

 

Just told me that what you say about heat isnt relevant.

[ThatCarlosGuy]

9 minutes ago, RoKa said:

Ah ok, just one more thing to take into consideration.

If you force air from the top and the front. Doesnt the front intakes push the hot air out?

It WILL work having intakes on the top, but it's just not done very often. it'll probably be slightly less efficient at dispersing the heat out of your case, that's why people don't do it. Front/bottom intake and top/rear exhaust is the tried and true method of air cooling. People prefer it for a reason I guess.

[RoKa]

3 minutes ago, ThatCarlosGuy said:

It WILL work having intakes on the top, but it's just not done very often. it'll probably be slightly less efficient at dispersing the heat out of your case, that's why people don't do it. Front/bottom intake and top/rear exhaust is the tried and true method of air cooling. People prefer it for a reason I guess.

Ah ok, I guess it just boils down to how my PC performs/looks like after a while. I just find it a waste not to use the top as a intake because it has a awesome filter which is hyped up everywhere. Otherwise I might as well buy the Graphite Series 760T from Corsair, which I wanted in the first place. But decided to change it to the case mentioned above because of the proper top intake/outtake with filter. Im planning on adding watercooling for the processor so I will have a radiator at the top. Im just not really 100% what to do at this point.

 

[ThatCarlosGuy]

2 minutes ago, RoKa said:

Ah ok, I guess it just boils down to how my PC performs/looks like after a while. I just find it a waste not to use the top as a intake because it has a awesome filter which is hyped up everywhere. Otherwise I might as well buy the Graphite Series 760T from Corsair, which I wanted in the first place. But decided to change it to the case mentioned above because of the proper top intake/outtake with filter. Im planning on adding watercooling for the processor so I will have a radiator at the top. Im just not really 100% what to do at this point.

 

Well buy it and just try it and monitor your temps. The worst thing that will happen is your temperatures will creep up slowly. If it does get a bit too hot, take the fans out or just flip them for exhaust and monitor your temps again. If it's better, keep it like that. If you're having a radiator on top eventually, you should be having that as exhaust anyway.

[RoKa]

3 minutes ago, ThatCarlosGuy said:

Well buy it and just try it and monitor your temps. The worst thing that will happen is your temperatures will creep up slowly. If it does get a bit too hot, take the fans out or just flip them for exhaust and monitor your temps again. If it's better, keep it like that. If you're having a radiator on top eventually, you should be having that as exhaust anyway.

http://www.corsair.com/en/hydro-series-h115i-280mm-extreme-performance-liquid-cpu-cooler

Im planning on buying this one.

What's the reason I must use it as an exhaust? Instead of an intake. I mean, the air from the radiator gets pushed and pulled out of the case really quickly.

[ThatCarlosGuy]

Just now, RoKa said:

http://www.corsair.com/en/hydro-series-h115i-280mm-extreme-performance-liquid-cpu-cooler

Im planning on buying this one.

What's the reason I must use it as an exhaust? Instead of an intake. I mean, the air from the radiator gets pushed and pulled out of the case really quickly.

Again, it's not that you "MUST" use it as an exhaust, but as well as hot air rising, you will also be throwing the heat from your radiator back into your case. It's all theory so take it with a grain of salt.

I've attached a picture I've found online and added airflow arrows. I've seen this method with watercooling setups. I know it's not an AIO, but you get the idea.

 

[not my image, google images]

REMEMBER, it's not neccessarily the amount of fans that dictates air pressure. It's airflow and RPM you need to consider. So if you have larger fans at the front running at a higher rpm than the smaller ones as exhaust, you can still maintain positive air pressure even if you have 1 or 2 more exhaust fans than intake.

[RoKa]

1 minute ago, ThatCarlosGuy said:

Again, it's not that you "MUST" use it as an exhaust, but as well as hot air rising, you will also be throwing the heat from your radiator back into your case. It's all theory so take it with a grain of salt.

I've attached a picture I've found online and added airflow arrows. I've seen this method with watercooling setups. I know it's not an AIO, but you get the idea.

[picture]
REMEMBER, it's not neccessarily the amount of fans that dictates air pressure. It's airflow and RPM you need to consider. So if you have larger fans at the front running at a higher rpm than the smaller ones as exhaust, you can still maintain positive air pressure even if you have 1 or 2 more exhaust fans than intake.

Ah ok, thanks for your time.

This has answered my question better than the videos I have watched. (gosh darnit Linus)

Ill be taking all this in consideration when building my pc.

Thanks again,

Roman

[ThatCarlosGuy]

 

Give this a watch, it does explain it very well