Require help with proper fan hub management

doyll said:
Indeed, mount intakes over vents in right panel near front of case.
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thx for the feedback. Just a question that's jargon related I guess. What's the meaning of 'mount intakes over vents' ?
In case I would replace the whole back, how am I supposed to arrange my PCIE devices ? I guess with extenders leaving them dangling inside the case ?
I recall having seen somewhere on YT some test with airflow setup on this case. Will try to find it back and will post the link if I do...
 
Inteke fans mounted on vents. Sorry for the confusion.
I wouldn't replace the back. It's a structural part of case. Pressed metal grills like in bottom and back of most cases is quite restrictive lowering airflow 29-71% compard to open hole. Link below has more info.
https://www.overclock.net/forum/22657923-post15.html

I have cut out vent grills and even cut the strips between PCIe slots out to increase vent area. That way the PCIe slot mounting system is still functional.
 
so if I want to leave the back as it is (only 1 fan), what would be the best intake-exhaust scheme knowing that the play field is a top-bottom-lateral one with the cooled vertical GPU? Logically speaking, cold air is best served from bottom no ? If you'd agree on that, that'd leave either the top or the lateral side for exhaust ? The back side could be either intake or exhaust.
But as you stated, bottom and top plate are partially obstructed by the metal mesh layout (and filters : but those could be taken out ?) so this will hinder air intake. I believe the lat panel is the one with the most clearance (would this be an argument for intake or exhaust?). The same goes of course for the back fan too...
 
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You don't need exhaust fans, same as you don't need pull fans on your radiator or on back of your D14. Good pressure rated fan/s pushing air into case, radiator, cooler move almost as much air as intake & exhasust / push & pull fans will. Using push/pull is 'stacking fans' and while it does not change the combined airflow rating of a single fan it does increase static pressure rating. Also, 2x fans make 3dB more noise than 1x fan at same speed, slow the 2 fans to same noise level and they will be flowing almost exactly the same amount of air as 1 fan at same noise level. This is true on cases, coolers and radiators. Also keep in mind stacking fans does not in mprove anything if both spin the same direction and there is no airflow straightener between them A radiator or cooler acts as airflow straigtener between fans on them. Case intake and exhaust fans are far enough from each other so no airflow straightener is needed.

End point here is using both intake and exhaust fans does not improve case airflow if case has enough exhaust vents. It's the same as push / pull on radiator or cooler. Even your D14 will cool the same with just middle fan as with 2x fans at same noise level. If you have 4x 120mm intake fans on vents and 5x 120mm exhaust vents with not fans case will flow the same amount of air with or without exhaust fans.
 
doyll said:
End point here is using both intake and exhaust fans does not improve case airflow if case has enough exhaust vents
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ok, so I'm not using any kind of radiator or ventilator, just the fans. I did get PWM ones so as not having to have them spin at max speed all the time, so db wise this should be ok.
Sorry if I don't get everything straight here, I'm really doing my first build... In my scenario, I still need to have to install my fans for intake and exhaust right ? So let's say I'm willing to use the 7 fans, would there be a difference in temps if intake were either on the bottom, top or lateral ?
 
ioverclockers said:
ok, so I'm not using any kind of radiator or ventilator, just the fans. I did get PWM ones so as not having to have them spin at max speed all the time, so db wise this should be ok.
Sorry if I don't get everything straight here, I'm really doing my first build... In my scenario, I still need to have to install my fans for intake and exhaust right ? So let's say I'm willing to use the 7 fans, would there be a difference in temps if intake were either on the bottom, top or lateral ?
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If you have at least as many exhaust vents (as much square inch/mm of vent area) as you have fan intake vent area (I like about 20% more empty exhaust vent area than intake vent area if intakes are not filtered vents) than you don't need to use exhaust fans.

You do not need to use exhaust fans as long as you have at least as much exhaust vent area as you have intake fan vent area. It's simple displacement. ALL AIR FLOWING INTO CASE HAS TO FLOW OUT!! For every 10x10x10cm volume of air flowing into case there has to be a 10x10x10cm volume of air flowing out.

How about this; Think of your case as a box van with side windows on both sides, front and back and it's in a pond 5' below the surface. Van is full of water. You can't flow any more water into van through a window without having same amount of water flowing out of van through another window. What flows in must flow out. The science of airflow is called 'Fluid Dynamics" because air flows like water (and other liquids) flow.
 
In layman's terms you can't 'suck out' heat. Heat moves from component to cooler to air. We move air into and through our case, cooler and then move air that warmed from cooler on out of case. We can only 'suck out' as much air as we have entering case. What is going in must also be coming out and what is coming out must also be going in. Remember, airflow is same principle as water flowing down a river or through a lake, ocean, etc.
 
Ideally we want a little more air entering through fans on filtered intakes than what fans are moving out .. that is if you insist on having your case setup as a push/pull unit. ;D Intake vent grills are almost always more restrictive than exhaust vent grills. Add filters on intakes and they are even more restrictive. We don't want fans pulling more air out of case than we have entering because then dusty air will be entering all other holes in case, even through USB socket, on/off switch, etc. Are you also going to put fans on both sides of your radiator? Because using both intake and exhaust on your case is same principle as fans on both sides of your fan.
 
ok posting an image of suggested setup. As I said, I shan't be using radiators at all, so only problem I'll have will be with intake vent grills on the bottom I guess. 4 fan intake (one on back, three on bottom) and 3 exhaust (lateral pane). The rationale being that :
- bottom gives fresh(er) air
- the back intake goes straight into the CPU cooler (I guess Zalman is fixed on Mobo in such a way that fans are vertical so they can benefit from the direct airstream intake from the back and push it to the lateral exhaust).
- putting the exhaust at the lateral side and not on top helps not blowing the GPU hot air towards the CPU, I hope it kinda swirls underneath the CPU and will be sucked out thru the exhaust before it does).
Does this make sense ?
Here's the pic:
https://ibb.co/nb6LTGc
(unable to embed for some reason...)
 
I would use side as intake like I suggested before. Grab a cheap digital thermometer with remote sensor off of river or bay and set sensor middle front of cooler intake to see what temp of air entering cooler is during high load run of 15-25 minutes. If air temp stays within a few degrees of room ambient you are golden.

ioverclockers said:
what would be the alternative with all the fans I have now ?
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But 3 back in their boxes and same for next build. :D
 
Do you need a back fan on your cooler or radiator? If you don't than you probably don't don't need one on the back of your case.

Best way to know for sure is monitor air temp entering component coolers and if it's more that 3c warmer than room after 20-30 minutes of heavy load than case airflow needs attention.
 
So if I understand correctly, I'll just be having 3 intake fans and that's it ? Won't that just make the air (heat up and) spin in circles inside the case ?
As I said, the Zalman does come with two fans integrated, so I suppose they're necessary..
 
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Re-read post 2, specifically read the link I gave you that explains how airflow works!

Also re-read last part of post #26!!

Now go back to post #2, open link and re-read "How Airflow Works" again! Hopefully that will help you understand fluid dynamics of airflow.
 
ok, this time I really read thru the stuff in detail.
I believe there was first of all a misunderstanding in terminology :

#2
We can't move more water into the van (case) through an open window (vent) unless we have another open window (vent) somewhere else in the van (case) moving the same amount of water (air) out through a window on other side of van (case).
Click to expand...

I had taken the word 'vent' in the technical sense of ventilator (some sort of equivalent to fan, so I wasn't really seeing what you were talking about). So basically, here it's a generic term in the sense of 'aperture', 'opening' (or window in your simile). That explains the meaning in #26...

Ok, so that clears a lot up for me.
The question I still have though (and that you also bring up in #2) is the fact that the 'vents' aren't necessarily of the same quality, i.e. the bottom, rear, and top plates having restrictive grills (and the top and bottom one having dust filters too). I believe the lateral side has less limitations in this regard.

So basically, what you're proposing is not a push-pull config, but rather a push-evaporate scheme, i.e. letting the air passively evaporate, exit the case thru the available apertures (I guess the grids). Is that correct ?

In my scenario, I would agree then to have 3 lateral intakes. But I do wonder whether the passive evaporating will be sufficient precisely because of the grid-dust filter obstacles.
I would incline to adding 'some' active exhaust in the form of a single 120 mm fan at the rear and to orientate the blow of the CPU fans in that direction. That would take out the major source of heat production in an active manner, letting the rest evaporate passively thru the other case apertures.

Hope I'm being a better student this time !
https://ibb.co/3hnzvhP
 
ioverclockers said:
ok, this time I really read thru the stuff in detail.
I believe there was first of all a misunderstanding in terminology :

#2


I had taken the word 'vent' in the technical sense of ventilator (some sort of equivalent to fan, so I wasn't really seeing what you were talking about). So basically, here it's a generic term in the sense of 'aperture', 'opening' (or window in your simile). That explains the meaning in #26...

Ok, so that clears a lot up for me.
The question I still have though (and that you also bring up in #2) is the fact that the 'vents' aren't necessarily of the same quality, i.e. the bottom, rear, and top plates having restrictive grills (and the top and bottom one having dust filters too). I believe the lateral side has less limitations in this regard.

So basically, what you're proposing is not a push-pull config, but rather a , exit the case thru the available apertures (I guess the grids). Is that correct ?

In my scenario, I would agree then to have 3 lateral intakes. But I do wonder whether the passive evaporating will be sufficient precisely because of the grid-dust filter obstacles.
I would incline to adding 'some' active exhaust in the form of a single 120 mm fan at the rear and to orientate the blow of the CPU fans in that direction. That would take out the major source of heat production in an active manner, letting the rest evaporate passively thru the other case apertures.

Hope I'm being a better student this time !
https://ibb.co/3hnzvhP
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'Vent' is a opening in our cases that air flows through.

Oxford dictionary definition of 'vent' : An opening that allows air, gas, or liquid to pass out of or into a confined space.

Which is exactly what I was using the word 'vent' to mean.

You are correct, in fact all in our cases flow differnt amounts of air. Link in post #22 is to info showing airflow differences and area blcoked by different kinds of vents.

Indeed, use intake fans to create a flow of air through the case. Sorry, I don't understand "push-evaporate scheme, i.e. letting the air passively evaporate". air volume is not changing but extremely little. When I compare air flow to water flow there is almost no change in volume. There is only movement. Sometiime an exhaust fan behind CPU cooler will change case airflow, but most of the time it doesn't make enough difference to be worth doing. As I say is optimizing case airflow link, sometimes exhaust fans help make air flow where we want, but that is the exception. Generally no exhaust fans is best.

I often block all vents in front half of case so the air front intake fans push into case has to flow more than half way through the case before there are any openings/vents it can use to leave case.

Sorry I jumped at you. It's just that how airflow works is as plain to me as the nose on my face, and sometimes I loose patients with people who have no understanding of how airflow works. And yes, my nose is very plain. :D
 
doyll said:
Sorry, I don't understand "push-evaporate scheme, i.e. letting the air passively evaporate"
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Was just my way of saying to simply let out the air that had been pushed in actively by the fans.
In my case, wouldn't it be beneficial to have a single exhaust fan at the back just opposite to the CPU cooler ? That way the Zalman would blow the hot air directly to the outlet, instead of having the hot air being "let out" by itself (probably by the top where it could still heat up the CPU a bit before it gets thru the grill and dust filter) ?

No problems with your nose :D. But I'm coming from OOB Macintosh land, where all the technical thinking and tinkering has been done for us ! As I said, this really is a first time build, so it's a journey full of discoveries ;)
 
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