Jump to content
Corsair Community

Fan Direction and Radiator mounting


Soupladel

Recommended Posts

So my first experience of AIO coolers was the original H100 and whilst it was ok, it was never great, from day 1 i had problems with grinding from the pump and should have returned it but made do by using a fan controller to reduce the voltage which sorted the problem but more than likely led to the pump failing.

 

I have now ordered a H100i v2 because i know it will fit my case etc...

 

So the question is what would be the optimum configuration? I have what is now an ageing system that i have upgraded with a 1060 6Gb gfx card and plan to overclock my 2700k to the maximum i can get away with.

 

I am using a NZXT Phantom Case, which precludes me from front mounting this, so my only option is roof only. The case has 2x 200mm fans in the roof and i will be mounting the cooler with a mount that came with the case so it sits just below these big fans.

 

In my relative inexperience i had the case fans in the roof pulling air into the case and onto the H100, the fans on the H100 were also set to pull air through the radiator into the case in a Push/pull configuration.

 

What i want to know is was this configuration remotely correct, or should i have had it set up so the air went the other way like an exhaust? my understanding is that would have been better overall for the system but not so for the CPU temps?

 

Additionally, when i binned the old h100, i rescued the two fans and all the screws.. Would there be any benefit adding these fans to the AIO cooler so it would be 4x 120mm fans mounted to the radiator in a push/pull config with a further 2x 200m fans sat above, my gut says this would be overkill and wouldn't really improve the airflow by much, if at all.

Link to comment
Share on other sites

Hey there ...

In most configurations, a top-mounted radiator it typically configured as exhaust. This works with physics (heat rises) and also the typical airflow design of a case (cool air in the front and bottom, out the back and top).

 

Looking at just the CPU temperatures is, honestly, a tad myopic. You need to look at the cooling of the entire system and, in your case, very specifically the cooling of that GPU and dealing with the waste heat that it generates. You've not mentioned if you have additional intakes or exhaust fans configured so it's really difficult to get a feel for your overall thermal environment ... but you'll need plenty of intake. Without intake and at least some additional exhaust, the interior of the case will get pretty warm with the waste heat generated from the GPU. If your radiator is configured as exhaust, this will have a negative impact on the coolant temperature which, in turn, will have a negative impact on your CPU temperature. It's not a simple answer because, well, it's not a simple problem. You really need to look at your thermal environment holistically and we don't have enough information here to do that.

 

Configuring push/pull with 200mm fans and the coolers, I've found, doesn't work as well in practice as one would expect. I did have a system that was configured similarly and I found that the 200mm fan on top of the radiator actually "backed up" the exhaust and caused my radiator to be significantly warmer with the larger fans than without. So this is something that I'd recommend that you test thoroughly, with a close eye on the radiator temperature throughout the process.

 

Configuring push/pull with the salvaged fans isn't a bad idea but it's likely overkill for your system. Furthermore, you won't be able to run all of those fans off of the controller on the pump; it just doesn't have enough power (1A) to properly power all of the fans AND power the pump as well. However, if you have a way to configure them and keep them (relatively) balanced, then it may work out for you. If those are the stock fans, just be aware of the noise.

Link to comment
Share on other sites

You are absolutely right about the physics, but there is something a little counter intuiative about warming a radiator that is intended to cool which is why I set it up as I did. However I also accept that an overall cooler system is also important.

 

As for overall cooling and airflow, there are the 2x 200mm fans in the roof, 1x 140mm on the front and 2x 140mm fans on the side panel which are all configured as intake, but only a single 140mm on the rear as exhaust, is which I realise is probably an error. All of these fans are directly controlled by the case’s inbuilt fan controller, therefore if I was to include the salvaged fans, I should be able to power these from the fan controller or even the motherboard as it seems to have a number of fan power headers

Link to comment
Share on other sites

I typically prefer to exhaust waste heat whenever possible. Most of this comes down to how much other heat you have to manage, with the GPU being the obvious other source. If you don't have a lot of steady GPU activity, then it probably does not matter. If you do, the combination of GPU and CPU waste heat in the center of your case becomes a lot for a single rear exhaust to deal with.

 

Specifically with your case, the question of whether the additional 200mm fans have any benefit has come up before. Frankly, I doubt it does anything for moving air through the radiator and there used to be a rather laughable picture on the case page of a 240mm sitting below them. 200mm fans are very diffuse in their flow and not optimized for that purpose at all. That would not be the way to do it. All that said, as exhaust the 200mm might be helpful for getting passively collected heat out that half vented top. Waste heat collecting up there and not exiting might cost you a few degrees in coolant temp because that is where the radiator resides. This is a very specific case question and the only way to solve it it to run it both ways and measure coolant temp differences. Either way, I don't see any needed special measures.

Link to comment
Share on other sites

So ... with all of that intake, I would:

1) Take out the top 200mm fans. You can give it a shot but from what I've seen they don't help the radiator temps.

2) Install the radiator as exhaust. Overloading with intake can cause turbulence and dead spots. You want a balance of intake vs exhaust with a slight to moderate bias towards intake. You currently have an extreme bias towards intake.

3) If you choose to salvage the old fans, you'll need a PWM controller from them. That's not likely to be the controller in the case. You'll also want to keep them balanced with the other set of fans. That's more difficult.

Link to comment
Share on other sites

Ok, I am going to hold my hand up here and say that fan controllers and PWM is a bit of an alien concept for me, certainly one I have done any research into yet, but is this something I am likely able to control from my motherboard or would it require a dedicated PWM controller?
Link to comment
Share on other sites

Ok, I am going to hold my hand up here and say that fan controllers and PWM is a bit of an alien concept for me, certainly one I have done any research into yet, but is this something I am likely able to control from my motherboard or would it require a dedicated PWM controller?

 

Hey ... no worries about raising your hand; that's what the forums are for.

 

There are two ways to control fan speed:

1) DC Voltage Control: Alters fan speed by altering the voltage supplied to the fan. These fans will have 3 pin headers.

2) Pulse-Width Modulation (PWM) Control: Alters the fan speed using a Pulse-Width Modulated signal to represent the duty cycle (percentage) of the fan while supplying a constant 12V. These will have 4 pins. Typically, the fans will also have a wider control range.

 

Do you need a separate controller? It depends on your motherboard. For most newer motherboards, it's easy ... they all support PWM. However, yours is a bit older and it may or may not ... or it may support PWM on a limited number of headers. You'll need to check your manual and board. 3-pin connectors will ALWAYS be DC-controlled. 4-pin will USUALLY be PWM or DC controllable but I have seen cases where the connector had 4 pins but only supported DC control.

Link to comment
Share on other sites

That’s curious because these Fans off the old H100 are actually three pin, the headers on the motherboard are technically 4 pin but slightly offset in the sense the plastic guide is in the centre of the first three pins then there is an extra fourth pin.

 

I am not at home to do further checking but I will later on tonight

Link to comment
Share on other sites

The offset is normal and expected; a 4-pin header will support both 3 and 4 pin fans.

 

It's unusual that the cooler fans would be 3-pin ... but that is an older cooler so that could be the case. All of the newer coolers are definitely 4-pin.

Link to comment
Share on other sites

The original H100 fans were three pin DC controlled and it was handled a different way than nearly all AIO coolers now. As mentioned, the new one will be PWM 4pin and you will need to use those to connect to the pump controller on the H100i v2.

 

There was a phase where motherboard manufacturers were putting "fake" PWM headers on their boards. It had pins thus suggesting PWM control, but it was not. You don't see this any more but your board is from that era when this was done. It was a cost saving measure and there is no way to know without really digging into the manual or probably better, a detailed online search. Usually the suspect models get their name in the papers. Most headers now are referred to as 3/4 pin AUTO, meaning they can handle 3 or pin fans in either DC or PWM.

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

×
×
  • Create New...