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Airflow vs pressure balance (dust reduction)

Hi.

 

I have a H700i with a 360 rad (ekwb PE) at the front  cooling the cpu. The gpu is air cooled (for now).

 

I have 3 silent wings on the rad as the vardars have a clicky noise. Intake of course.

At the rear i have a 140mm noctua fan as exhaust and at the top i have 2 120mm nzxt fans exhasuting air on the 2 most rearwards positions. Reason being i didnt want the air to be exhausted too early by installing the top-front fan.

 

This works well for temps but because theres not much intake so I get a lot of dust inside the case. I was thinking about adding intakes to have better control of the airflow and increase presure.

This would allow me to add filters and also there would be less dust being pulled in as the pressure is higher.

 

But I'm not sure where to add the intakes. I'm afraid of disturbing the airflow and increase temps.

 

Something I'm considering is to add an intake on the top-front. Which would push air downwards behind the rad (also decreasing pressure in front of the rad and potentially improving cpu cooling).

Also I'd make a divider and keep the top-rear fan as exhaust. Blocking the middle fan.

 

Do you think this would work?

 

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8 hours ago, Pawer8 said:

Hi.

 

I have a H700i with a 360 rad (ekwb PE) at the front  cooling the cpu. The gpu is air cooled (for now).

 

I have 3 silent wings on the rad as the vardars have a clicky noise. Intake of course.

At the rear i have a 140mm noctua fan as exhaust and at the top i have 2 120mm nzxt fans exhasuting air on the 2 most rearwards positions. Reason being i didnt want the air to be exhausted too early by installing the top-front fan.

 

This works well for temps but because theres not much intake so I get a lot of dust inside the case. I was thinking about adding intakes to have better control of the airflow and increase presure.

This would allow me to add filters and also there would be less dust being pulled in as the pressure is higher.

 

But I'm not sure where to add the intakes. I'm afraid of disturbing the airflow and increase temps.

 

Something I'm considering is to add an intake on the top-front. Which would push air downwards behind the rad (also decreasing pressure in front of the rad and potentially improving cpu cooling).

Also I'd make a divider and keep the top-rear fan as exhaust. Blocking the middle fan.

 

Do you think this would work?

 

If temps are okay and dust reduction is your only goal, I'd start by just removing the 2 top fans and seeing what happens.  Then the front rad will still act as an intake, but you'll only have one exhaust.  Theoretically positive case pressure.

 

In general, people seem to way overthink the case airflow and fan placement thing.  Most any standard mid-tower case with one or two intake fans and one rear exhaust will cool just fine.  This is of course excluding cases with wild designs (air restriction) or especially hot components.  But most cases a ton of intakes and exhausts are just not necessary (just more noise).

 

If the above doesn't work you might look at putting the rad up top (if it fits) and use it plus one rear fan as exhaust.  Add two intake fans up front and should be good.  This would trade slightly higher GPU temps with a front rad for slightly higher CPU temps for top rad, but the difference might not be that large.

Be sure to QUOTE or TAG me in your reply so I see it!

 

CPU Ryzen 7 5800X3D GPU EVGA 3080 Ti FTW3 Ultra MOBO Asus ROG Strix B550-F Gaming RAM Crucial Ballistix 3600 MHz CL16 32 GB PSU Corsair RM1000x COOLING Noctua NH-D15

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Yes my goal is to reduce dust without affecting temps. Or improving them. My cpu will go up to 60c (its not the best chip) although it's usually at 40 when gaming, and my gpu 72c so I'm happy with temps. 

 

I forgot to mention the fan curve on the top exhaust is dependant on gpu temps and actually help with cooling the gpu. The rest is based on cpu temps.

 

The rad does fit on the top but the fans need to go on the outside. Under the top panel. And have little room to breathe.

 

Maybe I could try what you suggested and change the rear exhaust to be dependant on gpu temp. The main reason it's based on the cpu at the moment is because I wanted to increase airflow as the intake was getting hotter as the intake is the cpu rad

 

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As you can see for your self from LTTs dust test:

 

Least dust comes in where there are no fans. So in the end best way to reduce dust is to use dust filters which you clean, and keep PC in room which is generally kept clean.

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4 hours ago, LogicalDrm said:

As you can see for your self from LTTs dust test:

 

Least dust comes in where there are no fans. So in the end best way to reduce dust is to use dust filters which you clean, and keep PC in room which is generally kept clean.

All my intakes are filtered. The intake fans look like new so the dust probably doesn't come from there. It settles on the gpu backplate and I noticed dust build up on the pcie slots.

 

It's not like super bad but I'm a bit of a perfectionist. Honestly most people wouldn't even be bothered by the amount of dust I'm talking about.

 

Also in the vid if I remember correctly (yes i watched it before posting this thread) they concluded the most dust comes from below. 

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4 hours ago, Pawer8 said:

All my intakes are filtered. The intake fans look like new so the dust probably doesn't come from there. It settles on the gpu backplate and I noticed dust build up on the pcie slots.

 

It's not like super bad but I'm a bit of a perfectionist. Honestly most people wouldn't even be bothered by the amount of dust I'm talking about.

 

It probably then falls through top vents when PC isn't running.

 

4 hours ago, Pawer8 said:

Also in the vid if I remember correctly (yes i watched it before posting this thread) they concluded the most dust comes from below. 

... Because there was fan there. The main conclusion was that dust comes in mostly where the intake fans are.

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Maintaining positive pressure is just a matter of running your intakes at higher rpm than the exhausts. 

If you ever need help with a build, read the following before posting: http://linustechtips.com/main/topic/3061-build-plan-thread-recommendations-please-read-before-posting/
Also, make sure to quote a post or tag a member when replying or else they won't get a notification that you replied to them.

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