Closer Examination

The Heatkiller Rad 360-S arrives inside bubble wrap all around for further protection on its way to you. Taking it off, we get our first good look at it, and I have the white version here. What this means is that the steel frame on the outside gets a white powder coat on the longer sides. At 398 mm long, it is also about average in length for triple 120 mm radiators, so it will fit into most cases compatible with such radiators, as long as they can accommodate the 30 mm thickness, of course. This review is of the 360 mm version in particular, but cases supporting 120 or 140 mm AIO coolers will thus also fit the Heatkiller Rad 120-S and 240-S. The width is actually slightly less, but basically on par with a square-frame 120 mm fan. On either side of the longer frame sections is a metal badge with "Heatkiller" stamped in, and this shield is applied with very strong 3M double-sided tape and extreme pressure, so you will be hard-pressed (get it?) to remove it. The badge gets a brushed finish for contrast against the clean powder coat finish, which is smooth and easy to wipe clean.


The shorter edges of the frame retain the stainless steel itself, and these get a similar brushed finish as the badge. We see thus that the two longer sections are screwed over these with overlapping corners, and this is no doubt going to elicit some comparisons with the EK-Coolstream series of radiators. I have to say that the build quality seems a few notches above the EK offering, however, and this is in line with Watercool having the reputation of putting out high quality products which take time, and in fewer quantity. Watercool might as well be considered a boutique brand in this field even today, and whether genuine or as a marketing excuse, the company does seem to take it in stride.


The fan holes are slightly inset from the frame and the standard 15 mm apart, which works with just about any case today. There are no screw shields underneath, but the fan holes are offset from the coolant tubes to where the M3 screws will not hit the coolant tubes whatsoever. At worst, you would bend the fins there if using a thinner fan or longer screws than necessary, which does nothing detrimental to the structural integrity of the radiator core. The threads are absolutely fine even with the random M3 screws I had to hunt down for testing.


The two BSP G1/4" ports on the end tanks are inserts into the frame, also threaded perfectly, and come with plastic inserts that are really only meant to keep dust out during transit. You would replace these with standard BSP G1/4" threaded fittings when using the radiator as part of your loop regardless. I wish there were more ports here, and competing solutions in this thickness class do provide more ports on the sides and even some on the other end for a fill or drain port. The core itself adopts the more typical U-flow design for the coolant, with either port being used as the inlet and the other as the outlet, which depends on your plumbing layout for the custom loop. There is a single row of fins/tube stacks with twelve ~1.35 mm thick tubes. This total of a 12-way parallel split of the coolant will decrease coolant flow restriction relative to single-row radiators with thinner tubes (think Black Ice Nemesis GTS), but generally suffers compared to multi-row radiators, as well as other single-row radiators with more and/or thicker tubing.

This is a departure from Watercool's previous radiators that employed the more industrial-style round tubes with straight fins in-between, though more in line with just about everyone else sans Aqua Computer, another German brand Watercool is most comparable to in my opinion. The fins are then also more traditional in being serpentine fins placed between the coolant tubes. It's not easy to measure fin thickness when assembled, but the fin stacks between the tubes are ~7.3 mm high and louvered lightly, which may increase the contact surface area for air flowing through the core, though it could adversely affect lower RPM/laminar flow regimes. The fins are 14–15 FPI in density, and the core itself is ~18 mm thick with a 6 mm plenum on either side between it and the frame, before the screws hit the fins. Without exactly knowing how thick the fin are, this combination leads me to believe that the Heatkiller Rad 360-S will be a low-airflow-optimized radiator. Watercool marketing says as much, especially on the lower end of fan RPM for the more noise-prioritizing customers. That said, we will see how the radiator fares in our testing over the next couple of pages.


Before we go ahead with testing, here's a look at the Heatkiller Rad 360-S in white next to the Heatkiller Rad 360-L in black, which is also powder-coated. The one that really caught my eye is the third option of brushed steel all around, which can be seen above in a photograph taken by a modder recently sponsored by Watercool. Watercool tells me that the goal with these new radiators is not to deviate from the company's workmanship and design language, and it is obvious that the new radiators retain the clear Heatkiller looks even without the badge. If anything, that badge might be a touch divisive from a brand that otherwise commits to very clean aesthetics, but it does further clarify this as a Heatkiller product.

[Update] Based on questions in the comments, I will also mention that these were among the first radiators made ready. As such, Watercool would have probably tested it first too, meaning they were likely flushed before they came my way. So yes, while the core was clean and there were no extraneous particles, this by itself is not indicative of a brand-new radiator.