Building a Quiet Water Cooled Gaming PC – Part 2: Water Cooling Components

It’s been a long time since I wrote Part 1 of this series, and the system is actually already built and has been running for several months. In Part 2, I will list out the various water cooling components I chose for this system and the rationale behind the choices.

Water Cooling Components

CPU Block: EK-Supremacy Clean CSQ – Acetal

EK Supremacy Clean CSQ Acetal

GPU Block: EK GeForce 780 GTX Ti VGA Liquid Cooling Block – Acetal (EK-FC780 GTX Ti – Acetal)

EK-FC780-GTX-Ti Acetal
The CPU and GPU blocks are from EK. The CPU block was chosen as reviews paint it to be one of the best performers. In particular, this comparison roundup shows that it performs the best on Intel’s Haswell chips. Since I will be using an i7-4770k in this build, The EK Supremacy block should be a good choice. An alternative that is also very good is the Koolance CPU-380I, which is better for the LGA-2011 (Sandy Bridge-E) platform, but certainly no slouch otherwise. I went for the Clean CSQ Acetal version for a clean black look.

The GPU block of course is dictated by the video card. I’ll be using an nVidia GTX 780, which means I’ll need a compatible block. EK has a nice Cooling Configurator which will tell you which block is compatible with your card. I also decided to go with a full cover block for the cleanest look and best performance.

Pump: Swiftech MCP655-PWM-DRIVE

Pump Top: Koolance COV-RP450

Koolance COV-RP450
I wanted to get the quietest pump possible, so the top contenders are the various D5 Vario pumps, which are said to be among the quieter pumps available. The top choice was initially the Koolance PMP-450 with the COV-RP450 top based on this Martin’s Liquid Lab Pump Noise Testing. This pump happens to be the same as the Swiftech MCP655, just with a different model name. However, I found that Swiftech also offered a PWM version of this pump, the Swiftech MCP655-PWM-DRIVE. Martin also reviewed this pump, and found that it could be run at even slower speeds to be even quieter than the PMP-450, giving it the noise crown. Thus, I had to choose it.

Because the Swiftech MCP655 series is the same pump as the Koolance PMP-450, it and the PWM version also fit the Koolance COV-RP450 top.

Reservoir: Koolance Reservoir Body BDY-TK120

Reservoir Top: Koolance Reservoir Top COV-TKTOP

Koolance Reservoir Bodies

Because the COV-RP450 has the capability to integrate a reservoir, I decided to keep things easy and neat by getting the Koolance reservoir and top attachments. I debated the size for a while, but I think the 120mm tall one provides a good balance between water amount, looks, ease of filling the loop, and being able to fit in the case. As far as I have read, the size of the reservoir does not really matter much for cooling performance; a larger one just makes it easier to fill the loop since you can poor more water in between pump start/stops. Of course, some may prefer larger ones for the looks as well.

Radiators: Alphacool NexXxoS ST30 Full Copper 360mm Radiator x 2

Alphacool NexXxoS Full Copper 360mm Radiator

Radiators have to be chosen depending on the balance of performance and noise desired in the system. While thicker radiators provide more heat dissipation potential, they also require faster spinning fans, which of course would make more noise than slower RPM fans. Thus, I decided to go with 2 360mm radiators that are 30mm thick, which work better with the slower fan speeds I will be running for low noise. Martin’s Liquid Lab once again reviewed the Alphacool NexXxoS ST30 (along with the thicker variants) and found it to be the best performer for slower fan speeds.

It turns out that the NZXT H440 case will fit two of them (one at the front and one at the top) as they are only 30mm thick.

Compression Fittings: Monsoon Free Center Compression Fittings

Monsoon Compression Fittings

Angled Fittings: Various Koolance/EK 30/45/60 degree fittings

For the fittings, I got two packages of the Monsoon Free Center Compression Fittings (6 per pack) in white to match my tubing (below). I really like the way these look compared to more traditional style fittings. Each package also comes with two sets of O-rings (you only need to use one) and a handy tool for installation, which can save your hands from getting too red.

I also got some miscellaneous angled fittings in case they were require to make the tubing work in the case (which did come in handy in parts).

Quick Disconnects: Koolance QD3 Male/Female Quick Disconnects

Because a water cooling setup is a pain to take apart and upgrade components later, I wanted to get some quick disconnects to allow easy removal of a portion of the loop for easier upgrades. In particular, I got 2 sets (2 male and 2 female) and put them around the GPU block connections so it will be easier to upgrade the video card in the future without having to drain the whole system. The QD3 system from Koolance seems to work well, and is the right size for the tubing I selected (3/8″). They also have ones for larger sizes.

Tubing: PrimoChill PrimoFlex Advanced LRT 3/8in ID x 5/8in OD

I chose 3/8″ inner diameter (ID) tubing as it seems the performance difference is not that great between this size and the slightly larger 1/2″ ID. For the outer diameter (OD), I went with 5/8″ so it would be rigid enough and not easily kink on tight bends. Having a difference of 2/8″ between the ID and OD is recommended; it actually means there is 1/8″ thickness of the wall of the tubing, since diameter measures the wall twice from one side to the other. Tubing with only 1/8″ difference between ID and OD means the wall is only 1/16″ thick, which is quite thin and is more susceptible to kinking/bending.

The PrimoChill PrimoFlex Advanced LRT seems to be well regarded and isn’t too expensive. I got 10 feet in white to contrast from the darkness of the other components and to match the fittings.

Biocide: IandH Dead-Water Copper Sulfate Biocidal PC Coolant Additive – 15 mL

Water: Distilled Water

In order to keep bacteria and other things from building up in the warm water loop, people either use a silver kill coil or some biocide. I opted for the latter as I think a clear tank looks a bit better. Plus, it seems simple enough to add a drop of biocide into the loop every 6 months or so to keep things running well. After running constantly for about 3-4 months, the water is as clear as the first day I put everything together.

I also used distilled water for the loop rather than any pre-made coolant, which can be very expensive.

Fans: Scythe KAMA FLOW 2 120mm Case Fan – 900rpm x 6

When deciding which fans to get for this build, a big determinant was price. The Noiseblocker NB-Multiframe M12 series of fans are highly regarded by SPCR, but they are also really expensive at around $23 each. Since 2 360mm radiators can use 6 fans, that adds up quickly.

Instead, I opted for the most inexpensive fans I could find that are also pretty good quality. I had wanted to get some Scythe Gentle Typhoon 12, but they are almost impossible to find in the US now. The faster AP14 and AP15 variants are still around, but they are too high in RPM for me. I noticed that the Scythe Kama Flow 2 fans were relatively cheap (around $10 each), and although they didn’t seem to be too popular on review sites (Xbitlabs included them in this roundup), I took a chance on them. They are indeed fairly quite, and when undervolted down to between 5-7volts, nearly inaudible, which is how I run them.

Fan Control: ZALMAN Fanmate 2

Speaking of undervolting, I am using a very basic fan controller that I got a long time ago. The Zalman Fan Mate 2 is cheap but it allows you to control all the 3pin fans easily when paired with the built-in fan hub on the NZXT H440. The H440’s fan hub connects many 3-pin fans, but does not provide voltage control by itself.

Fender Washers: M3 ID 3.2mm, OD 9mm Fender Washers

It is important to note that the NZXT H440 fan screw holes are rather large, and thus the screws that come with the Alphacool NexXxoS radiators, which allow you to attach the fans to the radiator and then to the case, won’t be able to be screw into the front and top of the case properly. To solve this issue, I bought some M3 size fender washers off eBay with an outer diameter of 9mm. I also tried some washers with an OD of 7mm, but they ended up being too small and could easily slip through the screw holes. Thus, I recommend an OD of 9mm for this case.

Conclusion and What’s Next

All of the components above should allow water cooling a single CPU and GPU system in the NZXT H440 case. In Part 3 (whenever that arrives), I’ll take a look at the system components that I used for this build.

UPDATE 2014-07-01: So I decided that there won’t be a part 3 of this series for a number of reasons (sorry Andrew in the comments!). Firstly, the most important part of the guides is already complete: the cooling system. The rest of the components is really up to individual choice for the most part. The main thing to be aware of is to find a matching GPU block for your video card of choice. Other than that, things like choosing a quiet PSU and using SSDs instead of HDDs are all part of the normal procedure for building any quiet computer system, not one specific to water cooling.

You will also want to choose a motherboard that will let you set the pump PWM speed dynamically based on system temperatures and perhaps use a different fan controller as well to do the same for the radiator/case fans if you want to overlock. Normally, the pump will run really quietly around 20% speed, but not all motherboards allow this low of a setting (some will only allow it using their software rather than in the UEFI/BIOS).

While this system can be very quiet if the pump and fans are run at appropriately low speeds, you may have to sacrifice some noise for cooling performance if you plan to overclock heavily. This system was never meant to be an great overclocker or keep temps super low while under load, but rather provide a quiet (if not completely silent) computer even while putting load on the system through normal usage such as games.


  1. Please update as soon as you are able, I plan on doing my first water-cooling build soon and I am going to be modeling it after your build.

    • Hi Andrew. Glad you were able to find the guide useful. Unfortunately I decided I won’t be writing a part 3 of this guide, and I updated the bottom of Part 2 with the reasons as to why as well as a few additional tips. Best of luck on your build!

  2. Hi and thanks for sharing your “silent” cooling system design. One unanswered question I didn’t see: how well did you meet your “silent” objectives ?? What about pump noise vs fan noise ? Thanks !

    • Hi Darrell, good question.

      For this system, the day-today operation was decently quiet, but there was an issue under load that baffled me for a while. While it would function at a decently low noise level to begin with, after a while and for seemingly random bursts, it got very loud for some reason. I thought it was the pump revving up at first, but after some very baffling tweaking to no avail, I discovered it was the power supply I chose. The PSU was semi, not fully, fanless, and the temperatures in the case got rather warm so the PSU started spinning up. I didn’t get a chance to try swapping in a fanless PSU to see how that would affect temperatures in the rest of the system before I decided no longer to go water cooling as it make upgrades and changing components more difficult than I like.

      I’m using a fanless PSU in my current build, which is inaudible to me during normal use outside of heavy graphics load (e.g., gaming), and would be during gaming except for 1 complication. I hope to write an article to share it soon.

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