new AIO - fans pull out or push in air?

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philb2

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I don't know the best way to set up the fans in my new Corsair H150i Elite AIO cooler, push air into the case or blow air out of my new Phanteks Enthoo Pro case. https://phanteks.com/Enthoo-Pro.html

The case front fan is 200 mm and the rear fan is 140 mm. The front, back, and bottom are all honeycombed with vent holes. The top is also honeycombed, but that's where I will be placing the Elite cooler. The bottom 4 3.5" drive bays will be filled for now, and I may add 3.5" drives to the remaining 2 free drive bays.

The AIO cooler is a new one for me. Until now I have always used air coolers for my CPU. If it matters, I also have an EVGA 3060 Ti and an ASUS ROG Strix-EA motherboard, with 1 NVMe drive installed. The Seasonic power supply blows hot air downward out of the case.
 
Monitor your CPU, mb and GPU temps while benching or gaming. The latter is what I personally go with when testing (usually for an hour or two)but benching is quicker.
 
Typically, you're going to use the front and bottom as intakes, and the top/back as exhausts. You'd already know if you were using some weird setup where an intake there would make sense. Just use it as exhaust on the top and be done with it :).
 
hititnquitit said:
Monitor your CPU, mb and GPU temps while benching or gaming. The latter is what I personally go with when testing (usually for an hour or two)but benching is quicker.
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I am not a gamer. That said I should do some benchmarks so I can monitor changes over time, like every few months. For now I'm going to follow GoldenTiger 's post and use the fans as exhausts.
 
Having the radiator on the front can make the CPU run cooler since outside ambient air is coming in over the radiator, but that puts a more heat into the case.
IMG_2159.JPEG

Having it on the top blowing out has all the heat from the gpu blowing through the radiator, so the GPU can be cooler and the CPU a bit warmer,
IMG_2204.JPEG

There was some tests done and it wasn't a significant change in temps for the GPU and CPU for either mounting location, so you can try both and see what works better for you.
All 3 of my AIO systems have the radiator on the top as exhaust.

IMG_3406.JPEGIMG_3443.JPEG
 
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Most cases have filters for the top so you can run a top intake as well.
 
philb2 said:
The top is also honeycombed, but that's where I will be placing the Elite cooler.
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Heat rises, so from a common sense perspective, it would seem to make sense to have the top as an exhaust. In practice however, any significant amount of airflow will more than overcome the effects of heat rising.

What is much more important is to maintain positive air pressure inside your case. That is, more intake vs exhaust. That has tremendous benefits, such as increased airflow into the components that exhaust air on their own, such as your PSU and potentially your GPU. Positive air pressure inside your case also makes sure that all of the holes in your case are exhausting air, rather than sucking in air. It makes it possible to control exactly where air is entering your case (the intake fans), which allows you to put dust filters in front of those fans. With negative case pressure, your case would be sucking in dusty and potentially hot air from every random hole, and working against your PSU and GPU fans that are trying to exhaust air.

I have a 360mm AIO at the top of my case, with 6 fans in push-pull, and acting as an intake for my case. It's not an issue in any way because I have lots of airflow and maintain positive air pressure inside my case.
 
your call. having them as intake will decrease cpu temp but up case temp and visa versa. ^^ that is all true but you can also clean your case...
 
GotNoRice said:
Heat rises, so from a common sense perspective, it would seem to make sense to have the top as an exhaust. In practice however, any significant amount of airflow will more than overcome the effects of heat rising.

What is much more important is to maintain positive air pressure inside your case. That is, more intake vs exhaust. That has tremendous benefits, such as increased airflow into the components that exhaust air on their own, such as your PSU and potentially your GPU. Positive air pressure inside your case also makes sure that all of the holes in your case are exhausting air, rather than sucking in air. It makes it possible to control exactly where air is entering your case (the intake fans), which allows you to put dust filters in front of those fans. With negative case pressure, your case would be sucking in dusty and potentially hot air from every random hole, and working against your PSU and GPU fans that are trying to exhaust air.

I have a 360mm AIO at the top of my case, with 6 fans in push-pull, and acting as an intake for my case. It's not an issue in any way because I have lots of airflow and maintain positive air pressure inside my case.
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How do you maintain positive air pressure inside your case?

So I guess I will have to do the "candle test" at the rear of my case, and then adjust the fans accordingly.
 
philb2 said:
How do you maintain positive air pressure inside your case?

So I guess I will have to do the "candle test" at the rear of my case, and then adjust the fans accordingly.
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More intake fans vs exhaust fans. Or, have your powerful fans as intake fans, and your weaker fan(s) as exhaust. If you use smart fan control, you can simply setup more aggressive fan curves on your intake fans, and very conservative curves on your exhaust fan(s). If your case has a lot of holes in it, then technically you don't even need exhaust fans as the air will find it's way out of your case one way or another, via the PSU, possibly the GPU, and the holes in the case; but I usually keep one exhaust fan in the back anyway.

Just take a piece of tissue paper and hold it up to some of the holes in your case. Does the tissue paper get blown away from the holes or sucked up against the holes?
 
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Intake or Exhaust is only 1/2 the equation. To push or to pull is the other half. I prefer push. For push, if the AIO is in the front of your case the fans should pull in and push through the radiator. If in the top then the fans would push air from case interior through the rad and exhaust out the top. There are numerous studies done on which is better (push/pull) and opinions are like A-holes we all have one but after many years and reading most of them I'm firmly in the push camp but only when push & pull is not an option. There are equally as many studies on positive and negitive case pressure. I prefer positive, but I'll spare you the details. Bottom line both questions should be asked push or pull and intake or exhaust.GL
 
owcraftsman said:
If in the top then the fans would push air from case interior through the rad and exhaust out the top.
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In no way does the radiator being on the top of the case automatically mean that it has to exhaust air outside of the case. It's fine to use the top of the case as an intake (air from outside the case going into the radiator), regardless of which side of the radiator the fans are installed on.
 
GotNoRice said:
In no way does the radiator being on the top of the case automatically mean that it has to exhaust air outside of the case. It's fine to use the top of the case as an intake (air from outside the case going into the radiator), regardless of which side of the radiator the fans are installed on.
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You can do what ever you want. I think the best advice would be to exhaust heat out the top of the case and not fight physics ie: heat rises. Why fight physics? Plus, if someone were to do as you suggest it would normally be filtered for dust control which would lower effective CFM and performance as well. That's two good reasons to set a top mounted rad to exhaust, for that matter even just fans in the top would be best orientated this way. I can think of only one good reason to set top fans to intake that being positive case pressure where all fans are set to intake. As for your last comment IMHO I prefer push for best performance and I'm not alone in that regard. If you want to push and set a top rad to exhaust there is only one side to do that.
 
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owcraftsman said:
heat rises. Why fight physics?
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Heat rises... slowly. Any significant amount of airflow will essentially make that irrelevant.

owcraftsman said:
Plus, if someone were to do as you suggest it would normally be filtered for dust control which would lower effective CFM and performance as well.
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Yes, any intake should have a dust filter on it; no different than if the radiator was installed in the front of the case. But you're also pulling in cold air from the outside through the radiator as opposed to hot air from the inside of the case through the radiator. That should more than make up for any lost CFM, and you always have the option of using more powerful fans or doing a push-pull setup to counter any reduced CFM from the dust filter.
 
Intake or exhaust is generally going to be up to the user depending on the results they want and usually needs to be tried both ways. Cases, hardware, cable routing and overall setups are different for everyone so what works great for one person may not work great for someone else.

I personally have my AIO mounted at the top as an intake with a push/pull setup. That's the way I wanted it because I wanted cooler air coming in to the top. I wanted more air blowing over the VRMs and all the other hot components at the top of the motherboard. In my opinion the single exhaust fan at the top/back of the case wasn't going to be enough for my piece of mind. The setup works the best for me.

The last time I cleaned out my case I decided to flip the fans on the AIO to see what happened when I set it up for exhaust. It didn't take me more than 10 minutes to decide that the next time I opened up my case I was going back to intake for the AIO. Under load the CPU was at least 7C higher and probably lost around 100mhz in boost. It's not a massive difference but it was a noticeable difference I didn't like as I run a lot of CPU heavy workloads. The NVME drive was also running 3C-5C warmer than before and that was at idle. This wasn't going to make any difference in the long run and generally I didn't care. However, both of these issues of higher temps showed that it's very likely everything on the top half of the motherboard was running hotter and there was absolutely no reason for that. The only advantage of setting the AIO fans to intake was a maybe 2C drop in temp under load for the Radeon RX570. 58C instead of the normal 60C wasn't going to make any difference there. For my setup it's obvious that intake for the top mounted AIO is the only way to go.

As soon as the new 6750xt came in (the next time I opened up the case) the AIO fans were flipped again for intake. CPU and NVME temps dropped back down to normal and likely everything at the top of the motherboard was also down to normal temps. The 6750xt has had no issues keeping cool and case temp doesn't seem to be an issue even with the new video card dumping an extra 60w-80w worth of heat into the case.

The moral of the story: the only way to know which is better is to try both out for yourself. It's annoying and can be time consuming but you only need to do this test once.
 
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