MenuWater Cooling Build - Part 4: Putting it all together

This is the fourth episode of my water cooling build which shows the installation of all parts in the new PC-Case. It's pretty tricky to install all the stuff in such a small room. If you didn't read the other parts of this buildlog, I highly recommend doing so.

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The masterplan

If you read the previous episodes of this buildlog you may remember that everything will be placed within the NZXT. H440 case. It is beautifully minimalistic designed and passes on some features like optical drive bays. 

Case OverviewCase Overview Case Overview CloseDownload Right frontRight front Right front CloseDownload

This design approach makes it somewhat difficult to place all the parts in it. The most important factor to me is the right airflow within the case. I want to achieve at least two things:

  1. The radiator should work as intake to get fresh air from outside the case, instead of warmed up air from the inside
  2. Any hot air should be removed from the case as quickly as possible to prevent hot-spots

These two requirements lead me to the following plan:

The Plan - FrontThe Plan - Front The Plan - Front CloseDownload The Plan - BackThe Plan - Back The Plan - Back CloseDownload

Some trade-offs have to be taken to accomplish the requirements. First of all mounting the radiator in the front renders all the drive bays in the front unusable. This means except for the radiator there can nothing else be installed in the front. That being said, I had a bad time figuring out where to install everything:

  • The hard disk: It has to be installed in the bottom of the case because this is the only slot left. This means I can never install another hard disk to extend memory or set up a raid.
  • The pump: Initially I was going to install the pump on one of the drive bays. This way I could have hidden it from the view through the side window. This is not possible with the above configuration and the only available space for the pump costs one of the SSD slots. Due to the fact that I have to SSD's I have to stack them on the one remaining slot.
  • The reservoir: To gain some extra space I decided to install the reservoir outside of the case and use the factory lead throughs for water tubing.

Configuring the PSU

I am happy that I have a modular PSU. Without that I don't even know where to put all these cables if you use the bottom HDD-slot. The following components want some power:

  • System (24-PIN): This one should be self-explanatory
  • CPU (8-PIN): I guess every modern CPU has an extra power cable ...
  • GPU (2x 8-PIN): Yes, ASUS seems to have some serious problems ... All their cards need much more power than the reference design 
  • SSDs/HDD (3x sATA): The SSD's need two power plugs and the HDD needs one. Unfortunately I still need to install 3 cables because powering the two SSD's from one cable would look silly and the HDD is too far from the SSD's to reuse one of the plugs of their cables.
  • Pump and lights (2x 4-PIN Molex): The pump itself has a 4-PIN Molex power connector. So do the red LED-strips I want to install.
  • Radiator and case fans: The fans will all be powered from the fan-headers on the mainboard. This will allow me to control the fans via software (cheaper and easier as an extra fan control system)

Easy going with a SuperFlower PSU:

PSUPSU PSU CloseDownload PSU ConfigPSU Config PSU Config CloseDownload

Hardware and radiator

First thing to install is the hardware (Mainboard, GPU, PSU, HDD), the radiator and case fans.

Installation FrontInstallation Front Installation Front CloseDownload Radiator & FansRadiator & Fans Radiator & Fans CloseDownload Installation BacksideInstallation Backside Installation Backside CloseDownload

One thing I always find important when installing fans is to make sure that the cables are always facing into the right direction so you can easily route them through the case. Other than that the installation is pretty straight forward.

I configured the radiator fans in PULL-configuration. This way, I gain two nice side-effects for future maintainance. The first is the removal of dust. If the fans pull air through the rad, the dust will stick to the open side of the rad where it can be easily removed. Push configurations require you to remove the fans from the radiator. When using the radiator as intake this means you need to uninstall everything from the case to uninstall the fans from the radiator to clean the radiator. The second advantage is cleaning or replacement of the fans. I can easily take them off seperately to clean or replace them. If one fan fails and no replacement is available the system also could run temporarily with that one fan removed. 


Before continuing with the installation, it's best practice to connect all the tubing. This will be much harder if you do wiring or final details before.

Hose Installation 1Hose Installation 1 Hose Installation 1 CloseDownload

Cutting the tubing is pretty easy too. Just install the tubing on one end to the source fitting. Then hold it to the target fitting ensuring that the tubing wont bend too much. In the above picture I connected the tubing between CPU and GPU to the CPU first. Then I took it with my hand at the needed length to reach the graphics card and cut it with a pair of scissors. If you wonder about the big loop I did there: the tubing was bending when I tried to force it into a smaller radius.

Cable management

Before installing the pump and proceeding with the leak testing, I had to ensure that all cables are in position to be connected to the hardware later on. I started doing some basic cable management and installed all cables I could without powering mainboard, CPU or GPU ...

Cable ManagementCable Management Cable Management CloseDownload Hidden HarddiskHidden Harddisk Hidden Harddisk CloseDownload

As you can see the cable management still is a mess in the new case. But fortunately this time the mess will be hidden behind the mainboard!

One other thing I had to install before installing the pump is the IO- and USB-cables. They are hidden behind the pump in the final layout and thus need to be installed first to prevent annoyance.

Mainboard Connector-AdaptorMainboard Connector-Adaptor Mainboard Connector-Adaptor CloseDownload

One of the above things comes in really handy if you don't want to struggle with the installation of all that small IO-connectors. Especially when your board almost touches the bottom of the case, this thing makes the installation a no-brainer.

Filling and leak testing

After completing the setup, the loop can be filled and leak-tested.

Leaktest PreparationLeaktest Preparation Leaktest Preparation CloseDownload Fillport DIYFillport DIY Fillport DIY CloseDownload

Prior to filling and testing it's recommended to put paper towels under all fittings. In case something leaks or a tube pops off the towel will catch a lot of fluid. This way you don't need to dry your hardware to continue. Afterwards filling can be done via the reservoir. Unfortunately I had no other funnel which fits the 1/4 opening of the reservoir, so I had to improvise with an ugly but functional DIY fillport setup.

The fluid I use here is DP-Ultra from Aquacomputer. Not that I think it's something special. But my main intent is long life and low maintainance cost. Using fancy dye will gunk up the system if you do not change fluid every six months. So this premixed uncolored fluid makes it very easy. It contains some anti-microbiotic stuff and prevents galvanic corrosion which happens when different metals are used within the loop. I am pretty sure there are much cheaper fluids which provide the same protection but in this case I do not want to experiment with stuff I am not familiar with.

Powering the PumpPowering the Pump Powering the Pump CloseDownload Leaktest for 2 hoursLeaktest for 2 hours Leaktest for 2 hours CloseDownload

To fill the loop you have to fill up the reservoir to the top and then power up the pump to make room for fresh liquid. Remember to stop the pump before the reservoir runs dry. I always recommend using two things for this:

  • A fake 24-PIN adaptor: In the picture above you can see the adaptor in action. It simply shorts two pins from the power cable to make the PSU think the PC is turned on.
  • Another great thing is a power socket with a power switch. You can plug your PSU to the socket while it is turned off... then install the fake connector and power cycle via the power socket. You could also use the PSUs own power switch in the back, but you do not need to fiddle around behind the PSU if you use the socket.

Here are some tips to fill and leak-test your water loop:

  • Always ensure that the pump does not run dry. It may damage the pump very quickly!
  • Choose a reservoire as big as you can. A bigger reservoir makes it easier to fill and deaerate the loop.
  • Never fill up the reservoir to the top. When the fluid changes temperature it will gain volume and needs some air it can spread into. A little air in the reservoir compensates that effect.
  • If you never built a custom loop before let the leak test run at least two hours! Some leaks can be really sneaky. In this build one of the pumps adaptors (inlet adaptor) was leaking a little. But it was about one drop of fluid per hour. If I had not put the paper underneath it and let the loop run for long enough I would not have noticed it during the testing.

Final setup

Now we have the loop filled and ready to connect the power.

Finished setupFinished setup Finished setup CloseDownload Finished setup BacksideFinished setup Backside Finished setup Backside CloseDownload

I used some cable straps to fix the tubing to the case and make the routing look a little better. Please note that you have to take that into account when you cut the tubing. It's no good idea to change the routing once the tubing is fixed to a certain length. You might squeeze the tubing or even put tension on one of the fittings. This could lead to a leakage which may pop up weeks after assembly.


Now that everything is working and the PC may boot up for the first time, we can close the case, take some nice pictures and compare the newly gained performance with the old air-cooled setup.