All-in-one (AIO) liquid coolers are very popular amongst advanced PC users for a variety of reasons, with a current market potential that easily rivals that of top tier air coolers. As such, nearly all of the companies involved in the production of advanced cooling products for consumer PCs are currently marketing AIO coolers. However, AIO coolers are so successful that even companies who do not currently produce any air-based cooling solutions have decided to market their own liquid-based AIO coolers.

Fractal Design, the renowned Swedish designer and manufacturer of PC cases, is one such company who has decided to offer their own AIO coolers. A couple of years ago they released the Kelvin series, a simple-looking AIO liquid cooler design, yet it was one of the few expandable kits. It also was available with a 360 mm radiator, which is very rare even nowadays.

Fractal Design just released an upgrade of the Kelvin series, the Celsius. The Celsius is based on proven hardware (i.e. Asetek parts), comes with Fractal Design’s X2 PWM fans, features interesting fan speed controls and is expandable. The new AIO cooler is available in two versions - the S24 and the S36. The only difference between these two AIO coolers is the size of the radiator that, as their names suggest, can support up to two 120 mm fans or three 120 mm fans respectively. We will examine both coolers closely in this review.

Packaging & Bundle

We received the Fractal Design Celsius coolers in large, strong cardboard packaging. The artwork on the packaging is subtle and clean, focused on pointing out the main features of the coolers. Inside the box, the coolers are well protected into a custom cardboard insert.

Both coolers share an essentially identical bundle, with the only exception being the manual. The S36 also has a few more screws for the third cooling fan. Other than that, inside each box we found the necessary CPU socket mounting hardware, screws and washers for the fans and for mounting the radiator on the case, and two cable management clips.

The fans provided with the Celsius AIO liquid cooling kits – two with the S24 and three with the S36 – are Fractal Design’s Dynamic X2 GP-12 fans. These PWM models have a very broad speed range, allowing the fans to operate anywhere between 500 and 2000 RPM. Furthermore, the serrated blades of the fans are supposed to reduce aerodynamic noise. Their engines feature a “LLS” bearing that we weren't able to find any information on – not even what the acronym stands for. A (catastrophic) disassembly of one of the fans revealed that it has what it seems to be an almost typical rifle bearing but with a magnet attached near the top. It would seem that the designer’s simple, yet effective concept was to attach a magnet at the edge of the bearing, using the magnetic force to repel the frame, reducing the friction between the stationary and rotating parts, thus significantly improving the longevity of the design. As such, the “LLS” bearing would typically classify as a “maglev” bearing engine.

The Fractal Design Celsius S24 & S36 AIO Coolers
Comments Locked


View All Comments

  • dave_the_nerd - Friday, June 2, 2017 - link

    So when do they sell one of these bundled with a Node 804?
  • Akkuma - Friday, June 2, 2017 - link

    The Arctic Liquid Freezer 240 & 120 seem to be the current bar for AIO. The price is better, the performance is better, and the sound profile seems better.
  • jabber - Sunday, June 4, 2017 - link

    Yeah I have the Arctic 240 and its great. Lot of kit for the money. One of the best around. I had put my old Corsair H50 in to try cooling my new 5820k rig but it just didnt have enough cooling power for that. Would have been nice to have had the Fractal option this time last year though to put in my new Fractal case...
  • CompLuva - Friday, June 2, 2017 - link

    I just got the s24 and my experience so far is that when the fans are at 100%, it's very loud. I can't compare to other AIOs since this is my first, but my old system which used a 120mm NFP12 Noctua was virtually silent at 100%. I know that's not exactly apples to apples, but still this thing is quite loud when at 100%. It also spins up and down a lot and the noise when doing that is pretty loud and noticeable too. The other issue with it is that since it uses it's own fan controller, I can't tell if the readout I'm getting in BIOS is for the pump speed or fan speed. I think it's for the pump since it'll read out 2800 and the fans are only 2000 rpms.
  • CompLuva - Friday, June 2, 2017 - link

    I retract my comment about the noise. I changed the positioning of the fans and radiator and it's much quieter now. I had the fans mounted to the case and then attached to the radiator. Turns out that small amount of space from the case mounting was causing a bunch of noise. Now I mounted the fans directly on the radiator and it's super quiet even at 100%. Very happy now. I've running 7700k @ 4.8 and 1.3v and max out at around 68-70 degrees when stress testing.

    Still can't see the fan speed though due to the integrated fan controller.
  • *zSnowz* - Friday, June 2, 2017 - link

    How reliable are these AIO coolers? I worry about leakage. How often do AIOs leak?
  • maximumGPU - Saturday, June 3, 2017 - link

    it's *very* rare. Quality has gone up a lot in the past few years.
  • verl - Saturday, June 3, 2017 - link

    The biggest worry for an AIO is how long the pump will last for. I think most ppl hit the 3-4 year range.
  • Makaveli - Saturday, June 3, 2017 - link

    ^^^^ This

    The H55 on my 7970ghz has been there for about 4 years now and the pump is alot noiser now than it use to be so it will almost be time to replace it.
  • nekronimus - Wednesday, October 18, 2017 - link

    There's a 5 year warranty on the S24/S36 as a whole. If you modify the loop i.e. detach any hose, you "only" have warranty on the individual parts. That's logical 'cause if say you drain and refill it and it performs bad it means you did a bad job at refilling, fractal can not held accountable for that.

Log in

Don't have an account? Sign up now