Case airflow / cooling suggestions (NZXT H500i + Ryzen 3700X stock cooler + Watercooled GPU)

[holyprof]

Hi all, my current setup is like this:

• CPU: Ryzen 3700x cooled by stock Wraith RGB cooler. Using manual fan profile with lowered idle RPM and 100% fan power above 70ºC to avoid overheat. Nevertheless, it's noisy and hot.
• GPU: EVGA 1080 Hybrid, AIO watercooled. The radiator and pump are overpowered, probably same as the 1080Ti so idle and load temps are pretty low, even with fixed fan speed of 800 RPM.
• Case is NZXT H500i, which i love for its awesome cable management and attention to details to make the build process easier and good-looking.

In my old case, i had the GPU radiator on the top (it had 2x120mm windows), pulling air from inside the case. Using hot air from inside the case wasn't a big problem because the GPU cooling system is probably sized for a much hotter card (1080Ti Hybrid). It barely hit 65ºC under combined CPU+GPU torture tests.

The new case only has a single 140mm top window, aligned with the CPU socket (see attached picture). That is fully logical (except for my awkward setup), if one wanted to put the CPU radiator there. But with CPU air cooler, i can't mount my GPU radiator on the top window.
So I put it on the front instead, following advice I found on the forums, with the radiator higher than the GPU. This way, it blows hot air directly to the CPU area (and the CPU cooler is not great already).

I'm asking for advice, did I took the right decision, and how can I upgrade / modify my setup to get better results?
Editing fan profiles and putting the CPU on "Ryzen power save mode" in Windows, I managed to lower fan noise to "acceptable", but I'm occasionally using my PC for sound and video editing and noise is not low enough for that.

My options might be:

• Live with it;
• Buy ultra low noise air CPU cooler like the Scythe Ninja (I heard it's really good);
• Buy AIO CPU watercooler with 140 mm radiator (I don't like watercooling much and don't have any experience or knowledge in this area)
• Anything else you guys could suggest would be welcome

 

[sneekypeet]

Any reason why the GPU rad is not hanging on the back? That way it dumps the GPU heat out of the chassis. If it fits, that is what I would do, and put a fan or two in the front of the chassis.

 

[DeathtoGnomes]

try to mount the radiator to the rear exhaust port. Ideally, the top exhaust is best but only if it reaches.

 

[holyprof]

Any reason why the GPU rad is not hanging on the back? That way it dumps the GPU heat out of the chassis. If it fits, that is what I would do, and put a fan or two in the front of the chassis.

It won't fit, for two reasons. It would touch the CPU cooler and block its airflow, and the motherboard VRM heatsink won't let me install any radiator here (it's visible in the picture).

 

[FreedomEclipse]

It won't fit, for two reasons. It would touch the CPU cooler and block its airflow, and the motherboard VRM heatsink won't let me install any radiator here (it's visible in the picture).

Upgrade the CPU cooler to a 240mm AIO - 240 AIO radiator goes on the front and the GPU one goes at the back. no clearence issues problem solved.


Or get a better case

 

[holyprof]

try to mount the radiator to the rear exhaust port. Ideally, the top exhaust is best but only if it reaches.

Sadly, both top and rear positions are blocked by CPU cooler and the rear is also blocked by the motherboard VRM heatsink. I guess i'd have to live with it unil I jump the gun and buy a CPU watercooler.
Maybe if i can get my hands on a low-profile 120mm fan for the GPU radiator, it might be able to fit in the rear position.

Upgrade the CPU cooler to a 240mm AIO - 240 AIO radiator goes on the front and the GPU one goes at the back. no clearence issues problem solved.


Or get a better case

Any specific brand / model you can suggest? I would prefer single 140mm radiator in the top position but I'm not sure those exist.

Just discovered that 140mm AIOs really exist. A quick search returned those:

• NZXT Kraken X42 Rev 2
• Corsair H90
• Cooler Master MasterLiquid Pro 140
• Cooler Master Nepton 140XL
• NZXT Kraken X40

As already mentioned, I don't have any experience or knowledge with watercooling. Can you recommend any of those for my case? RGB light and looks aren't important. It's low noise (both pump and fan) and performance that matter to me.

 

[Dinnercore]

Sadly, both top and rear positions are blocked by CPU cooler and the rear is also blocked by the motherboard VRM heatsink. I guess i'd have to live with it unil I jump the gun and buy a CPU watercooler.
Maybe if i can get my hands on a low-profile 120mm fan for the GPU radiator, it might be able to fit in the rear position.


Any specific brand / model you can suggest? I would prefer single 140mm radiator in the top position but I'm not sure those exist.

Just discovered that 140mm AIOs really exist. A quick search returned those:

• NZXT Kraken X42 Rev 2
• Corsair H90
• Cooler Master MasterLiquid Pro 140
• Cooler Master Nepton 140XL
• NZXT Kraken X40

As already mentioned, I don't have any experience or knowledge with watercooling. Can you recommend any of those for my case? RGB light and looks aren't important. It's low noise (both pump and fan) and performance that matter to me.

A single fan radiator has limited heat exchange and I would not really recommend them. If possible go 240mm or 280mm, as the price/performance is drastically better.

In the meantime, on the setup you have right now you can go reverse airflow to stop the GPU dumping heat in the system. Make the top and rear fan intake and the GPU radiator on the front exhaust. This would work best if there is an additional fan on the front that you can switch around too, as the fan on the radiator may not be able to completly push the air out the front by itself.

 

[FreedomEclipse]

Sadly, both top and rear positions are blocked by CPU cooler and the rear is also blocked by the motherboard VRM heatsink. I guess i'd have to live with it unil I jump the gun and buy a CPU watercooler.
Maybe if i can get my hands on a low-profile 120mm fan for the GPU radiator, it might be able to fit in the rear position.


Any specific brand / model you can suggest? I would prefer single 140mm radiator in the top position but I'm not sure those exist.

Just discovered that 140mm AIOs really exist. A quick search returned those:

• NZXT Kraken X42 Rev 2
• Corsair H90
• Cooler Master MasterLiquid Pro 140
• Cooler Master Nepton 140XL
• NZXT Kraken X40

As already mentioned, I don't have any experience or knowledge with watercooling. Can you recommend any of those for my case? RGB light and looks aren't important. It's low noise (both pump and fan) and performance that matter to me.

Kracken X52 or X62

 

[oxrufiioxo]

A 140mm is a waste of money.... Just grab something like this.

EVGA CLC 240mm All-In-One RGB LED CPU Liquid Cooler, 2x FX12 120mm PWM Fans, Intel, AMD, 400-HY-CL24-V1 LGA 1700 Compatible - Newegg.com

Buy EVGA CLC 240mm All-In-One RGB LED CPU Liquid Cooler, 2x FX12 120mm PWM Fans, Intel, AMD, 400-HY-CL24-V1 LGA 1700 Compatible with fast shipping and top-rated customer service. Once you know, you Newegg!

www.newegg.com

 

[DeathtoGnomes]

I Have to agree, the CPU cooler should be a 240 or 280, not a single.

a slightly large case would be better as well.

 

[ne6togadno]

Sadly, both top and rear positions are blocked by CPU cooler and the rear is also blocked by the motherboard VRM heatsink. I guess i'd have to live with it unil I jump the gun and buy a CPU watercooler.
Maybe if i can get my hands on a low-profile 120mm fan for the GPU radiator, it might be able to fit in the rear position.

mount rad inside the case and fan on the outside. rad looks like 25-30mm thick so if you replace the fan at the back with the rad and mount fan outside of the case it should fit.
later when you get new cpu cooler you can mount it properly.

 

[holyprof]

mount rad inside the case and fan on the outside. rad looks like 25-30mm thick so if you replace the fan at the back with the rad and mount fan outside of the case it should fit.
later when you get new cpu cooler you can mount it properly.

Thanks, I will definitely do that the next time I'm changing something inside or when I open it for cleaning.

 

[ne6togadno]

Thanks, I will definitely do that the next time I'm changing something inside or when I open it for cleaning.

make sure you set the fan in the direction to pull air out of the case.
cause if you will flip it other direction you will have same case as now but with time wasted for rearrangement

 

[John Naylor]

There are rules to water cooling that people jut refuse to comply with cause they heard their science teacher say hot air rises. If manufacturers wanted you to exhaust air out of your case, they wouldn't be telling you to do the exact opposite in the written instructions they supply with their products.

Radiator fans always blow in ... no exceptions ever unless you want whatever you are cooling to run hotter. Let's 'do the math.

Ambient Air = 23C
Inside Case Air = 28C
Coolant Temp = 33C

Coolant is proportional to Delta T, so ....

Delta T (Intakes) = 33 - 23 = 10C
Delta T (Exhaust) = 33 - 28 = 5C

Intake air provides TWICE the cooling to the water block than exhaust

The 500i is an attractive case, great cable routing too ... it is a bit weak on the cooling design

So yes you did the right thing with that case.

Now if you put a top fan in blowing out, which is a goiod thing in and of itself, it's not in this case. Yes hot air rises , but it's an extremely weak action ... especially in the face of a spinning fan. Remember that your intake fan have filters which can restrict air flow by as much as 33%. When designing building and especially kitchen ventialtion we do whas is called air balancing. let's do the math using 25% restriction for your filter and radiator when filter is moderately dusty and the ventialtion provided by the fan = V ... which will be about 50% of what it actually says in the specs:

Intake = V x 1 x 75% = 0.75
Exhaust = V x 2 x 100% = 2.00

As ypu can see, the exhaust is almost 3 times the intake which means we have a negative pressure situation, not a bad thing (other than dust) in and of itself but how will that make up air get in ?
Well one place would be that unused fan mount in the front ... it's filtered so that would be one potential source. But air will follow the path of least resistance and it's will meet less resistance coming in thru all those vented slot covers and rear grille.

Now howid your PC positioned ? is it under your desk ? is it pushed back on your desk against the wall ? With 3 times the air going out then in, air is going to come in thru those svented slot cover sand rear grille. What's the air like back there ? Isn't your warm case air being exhausted back there ? Isn't your PSU throwing all it's exhaust heat back there ? So what do ya thing the air is like back there ? It's air that has been preheated by your PSU and all your interior components ... you aren't exhausting hot air, you are recycling it.

By the way, if anyone thinks that 50% isn't real, read this:

Why Static Pressure & Max Flow Specs Are Poor Measures of Fan Performance

This is just a quick graphing demonstration of why fan box specs using static pressure and max air flow are generally poor tools in comparing fan performance. Very much like pumps, fans have a pre…

martinsliquidlab.wordpress.com

best bet would be to take that rear exhaust fan and put it at the front under the GFX rad ,,, assuming it fits. Now the math chnages

Intake = V x 2 x 75% = 1.5
Exhaust = V x 1 x 100% = 2.00

Positive pressure sityain and now no air coming in thru slot covers and rear grille .... we use some very high end technology to test air flow in these situations. When my son moved out and bought his own house, he left his fog machine from his garage band days here. It works great for testing

Amazon.com : Chauvet Lighting DJ 700 Hurricane Fog Machine, Black (H700) Premium : Musical Instruments

Amazon.com : Chauvet Lighting DJ 700 Hurricane Fog Machine, Black (H700) Premium : Musical Instruments

www.amazon.com

In the original setup that you have now, pointong the discharge between the wall and the case rear will have the case fill quickly with fog. Switch it as described and fog is blown away. You can even have all 3 fans blowing in and just the rear blowing out ... we often have all top, bottom, front and side fans blowing in and just rear fans blowing out on builds with lots of rads.

next time you do this I would ....

1. Buy a case with multiple front, bottom and top fan mounts. Phanteks has very similar cases as NZXT with as good or better cable routing and much more fan mounts, AIOs are easy to install up top. The Luxe modesl even puts the top fans in an "attic"

2. Avoid hybrid cooling ...
a) Ever wonder why a 95 watt CPU warrants a 2 or 3 x 120mm AIO and a 200 - 300 watt GFX card ony has one ?
b) Hybrids don't help with the VRMS and memory.

3. Avoid CLCs ....
a) They rarely do better than the better air coolers and when they do, the downside is extreme noise.
b) Each provides you with the opportunity to conduct a science experiment in galvanic corrosion
https:// martinsliquidlab.wordpress.com/2012/01/24/corrosion-explored/
https:// www.youtube.com/watch?reload=9&v=a_r4tWpMHHI&feature=youtu.be&t=8
https:/ /www.youtube.com/watch?v=HC1kzO_gIp4
c) Corrosion inhibitors have a useful life of 18-24 months ... you have no means to add fresh stuff
d) weak-ass 0.11 gpm pumps .... 1.0 gpm recommended as a minimum
e) You can expand the loop.

4. EK and Swiftech (also Aerocool sorta) actially have products that suffern from none of the above constrictions. Other than EK, they are cheaper than Krakens Corsairs CLC alternatives.

5. The Swiftech model comes in 2 x 120mm ($135) and 3 x 120mm ($165) verisons. It's quieter than CLCs, RGB is much more sedate, has a reservoir, allows beleeding, allows changing coolant, adding corrosion inhibitors, 1.0 + gpm pump, you can add more blocks more rads. In a typical $150 case, you could put a 3 x 120mm AIO with quiet fans to start, than add a 2 x 120 radiator and GFX water block at a later date.

$165 - 3 x 120mm Swiftech for CPU w/ reservoir
$40 MSI GTX 2080 Seahawk EK X w/ EK Full cover water Block $675 w/ water block preinstalled - $635 for MSI Gaming X Trio = $4-0 for block
$50 2 x 120mm radiator

Add some coolant, tube and a few fittings and you have an system equivalent to a custom loop for $300 ... the 3 x 120mm system however will cool a lot better than any CLC + hybrid combo and be much quieter.... all for $165

 

[holyprof]

@John Naylor
Well, that was the advice I was looking for when I opened this thread. Thorough, science + real life based, respecting my current configuration.

The idea of reversing the top fan might work, I noticed that most of the hot air is exhausted from the back, even though the top fan is 140mm vs 120 on the back. Breathing fresh air directly on top of CPU cooler seems like a good idea. My rear fan is a high-airflow model, opposed to the top one, which is low-airflow / low noise one, so I guess it will be able to pull all the hot air and let the front and top fans supply fresh air from outside the case.

I spent some time digging AM4 coolers and noticed that cheap, well-built air coolers are almost as good as a water cooler, while costing less than half, and in many cases producing less noise.
Too bad Arctic haven't built a new version of the excellent i30 I have on my i5-4690K. The Arctic 33 which is supposed to replace it is somehow weak and not so silent.
Living in a small periferic country makes things even worse, not all fans that exist are available for purchase here.
If I forget about the colours, the Noctua NH-U12S seems perfect for my system - to cite a review I found last night

The NH-U12S from Noctua brought me back to the days of my past. It just goes to show that you don't have to go and spend $80 to $100 to get something that can hold its own in our charts, and still be dead silent while doing it.

Read more: https://www.tweaktown.com/reviews/5417/noctua-nh-u12s-cpu-cooler-review/index10.html