i didnt want dust coming in my case so i cut some dust filters and taped it on my case thoughts?

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Yep. Have the fans still face the exact direction they are now, but you'd be pulling air through the radiator instead of pushing air through. At lower rpm, it's actually more effective. Then it's easier to clean off just the radiator front instead of removing everything to get between the fans and rad.
It will probably help to some extent, but there are some other things to consider:
Is the airflow restriction worth the dust prevention?
How much dust will that actually prevent, since they arent really proper filters?
What about the other openings on the case?
Is there actually any air going in the case there?

Honestly, the effort and money invested in most dust filter setups is more than if you would just clean the PC.
They are a good idea, to an extent.
 

Dugimodo

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To stop dust you need a positive pressure arrangement with filtered intake fans, then those bits you covered will have air coming out not going in and there will be no need to cover them.

Positive pressure is when you suck more air in than you blow out for example with 2 intake fans and 1 outlet fan.

Negative pressure is where you blow more air out than you suck in, that causes air and dust to find it's way into every possible hole. It cools well but is a nightmare for dust getting everywhere.

So if you want a clean PC filter the intake fans and make sure they move more air than the outlet fans. What you attempted will either make no difference or just make the dust find another way in, no case is air tight.

My 2c
 

Karadjgne

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Close. Much also depends on the fans. There's almost always a 120mm rear exhaust (don't ask me why in most cases) that tends to run high rpm. That creates a significant vacuum in the surrounding area of the case. Which can and will be a fresh air/dust draw from the pci slots and other small gaps directly under the fan. Which of course are not filtered. This'll happen no matter how much the case is supposedly 'positive' pressure.

Also, unless all case fans are run at max speeds consistently, and are identical fans, you'll not get consistent results. Different fans have different cfm curves at different speeds, so even if you have 3x 120mm intakes, and 2x 120mm exhausts, you can still have a negative pressure case if the cfm of the exhausts exceeds the cfm of the intakes. And then you speed up the fans and the cfm curve changes and the case goes from negative to positive.

The only way around most dust accumulation is to seal up the case as best as possible. Fill the cracks, cover unused fan ports, if using top fans, cover when not in use etc. This'll mean that as much as possible, any air intake will be filtered. Then positive/negative really has no affect, a balanced intake/exhaust being preferable for airflow characteristics.

Also, dust isn't all one size, there will always be micro particulate dust that'll work its way through anything but the most expensive HVAC filters. So no matter what you do, you will get dust. Period. The only thing different will be the frequency of required periodic cleanings.
 

Dugimodo

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That's all true but you can still minimise the dust fairly simply by just using the same type of fans all round and having more intake than outlet. Nothing is perfect but it definitely reduces the dust without having to put too much though into it.

Another point to add to all that information is that filtered fans move less air than unfiltered ones and you don't filter outlet fans so it's not a straight 1-1 calculation, you could have 3 inlet and 2 outlet fans of the same design and end up with very balanced air flow due to the restriction on the intake fans.

The reason there's almost always a 120mm rear exhaust is from a cooling point of view that's the single most effective fan - well except it would be better on top of a lot of cases but the rear near the top is very good also. If you were only going to have one fan and expect it to help that's where it should be.

Intake fans help target an area for cool air, and control where it comes from so you can filter it, but exhausting the hot air from where it is most likely to accumulate in hot spots is better for cooling in most situations.

It is of course totally possible to only have intake fans if the case is designed well and still have great cooling, but the exhaust fan is still the safest universal option.
 

chensonnyy

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well I have 2 exhaust fans, one in the rear and one on top, and I have 2 intake fans, but the in front of the intake fans is a dust filter and behind the fans is a radiator, which restricts air. because of this more air leaves the case that comes in. which causes negative air pressure. Should I slow down the exhaust fans to compensate for the intake fans?

 

Karadjgne

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Yes and no. The only time a rear exhaust is of any benefit is with tower style aircoolers which put their exhaust directly at the case rear exhaust. For aios mounted topside, radial air coolers, downdraft aircoolers, the rear exhaust is nothing but in competition with any top mounted fan. Heat rises, and in the old, solid top AT type cases and many prebuilts, the heat will accumulate at the top, so rear exhaust made sense. With top clear exhausts, it's better by far to allow the heat to go straight up and out, than physically trying to force it 90° sideways. With aios top mount, a rear exhaust vacuum will steal air from the aio fan vacuum, mitigating part of its ability to put air through the rad, not a good idea.
 

Karadjgne

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That setup is fine. You really won't have to worry too much about dust, the case is pretty tight as is. The only thing I'd change is the location of the intake fans. I'd put them inside in a pull configuration. That way when you pop the front off the case, you'll have access to the radiator for dust removal (I use the brush attachment on my vac, makes quick work for that specifically) instead of having to pull the radiator off to get the dust accumulated between the fans and rad.
 

chensonnyy

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so basically you're saying to put the fans behind the radiator, and the radiator in front? Essentially switching their places?
 

Karadjgne

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Yep. Have the fans still face the exact direction they are now, but you'd be pulling air through the radiator instead of pushing air through. At lower rpm, it's actually more effective. Then it's easier to clean off just the radiator front instead of removing everything to get between the fans and rad.
 
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chensonnyy

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one last question. Will changing it make a big difference? Like noticeable ones?
 

Karadjgne

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In some aspects, yes. You'll have unrestricted airflow right to the gpu coming from the intake fans. They'll not be obstructed by the radiator. Cleaning will be far easier. At lower intake rpm, the fans are more productive and efficient, basically good for 1000rpm or less. At @1500 rpm, push is better because of cfm. Most times the fans won't need to be maxed out. What most ppl fail to realize is temps below @70°C on a cpu are all the same, so it's pointless to max out fans rpm just to go from 57 at loads to 53. Only makes things louder for no gain. Internal fans have lower audible noise, it's lost inside the case. With the fans towards the outside, you'll hear them more at higher rpm.

In some aspects no. You have a radiator at front intake. Cpu temps will be slightly lower due to outside air directly affecting the radiator, instead of case exhaust air. Case temps, gpu temps etc will be slightly (by @2-3°C higher, but this might be offset by a more rigorous amount of air from the intake fans at pull.) So at load temps, gpu will be pretty much unaffected.

By far, the biggest issue with pull at intake is with lrd/RGB fans. Unfortunately the side you'll get to see is the uglier backside, not the pretty lighted side.