All-in-one water-cooling kits such as Antec’s Kühler H2O 920 have been around for a few years now, providing a taste of the water-cooling high life for much less than the cost of a bespoke loop. With cooling abilities that are on a par with those of high-end air coolers, and the advantage of placing little in the way of weight, stress or obstructions on the motherboard, these kits have become genuine alternatives to the towering stacks of copper and aluminium cooling fins and heatpipes that typically sit on top of our CPUs.
Click to enlarge
As the design and manufacture of integrated water-cooling systems is such a complex process, only two OEMs are currently producing units for the consumer market – Asetek and CoolIT. In the past, Asetek liquid coolers have been sold by Corsair under its H50/H70 branding, while CoolIT has traded under its own name with the Domino and Eco coolers. Recently, there has been a shake-up, however, with Corsair adopting CoolIT’s hardware and the long-established cooling brand Antec partnering with Asetek for its new Kühler H2O range.
The Kühler H2O 920 is the range-topper and, thanks to its Asetek roots, it shares more than a few design traits with the Corsair H70. Antec has included plenty of new features, though, which should make for a cooler that’s worthy of its £80 price tag.
The most noticeable feature of the H2O 920 is its 49mm deep radiator and the pair of 120mm cooling fans attached to it. The radiator’s cooling-fin density is very high, much more so than most radiators, providing a large surface area for improved cooling.
High fin-density can cause issues on coolers with just one fan, as the fan’s static pressure isn’t sufficient for effective airflow. Thankfully, the H2O 920 uses the two 120mm cooling fans in a push/pull configuration, which ensures that there's plenty of air flowing through the radiator, even at comparatively low fan speeds.
Click to enlarge
The radiator is designed to be fitted to any available 120mm fan mount in your case and, unlike the Corsair H70, Antec recommends installing the H2O 920 in an exhaust configuration, with one fan pushing air into the radiator and the other expelling it out of the case. This has the obvious advantage of not dumping the heat from your CPU back into your PC.
Running from the radiator are two rubberised hoses, replacing the plastic ribbed hoses of previous liquid coolers based on Asetek’s designs. These are still surprisingly stiff (stop giggling, you at the back) to prevent them from developing kinks, but they're much more flexible than their plastic predecessors. The fittings to the radiator are extremely secure, while the fittings to the waterblock can be rotated to make installation easier. All the hoses are also pre-fitted to prevent any leaks, meaning that there’s no way to refill the H2O 920; it’s designed to run maintenance-free for its lifetime.
At the heart of the H2O 920 is a combined waterblock, pump and fan controller arrangement that sits on top of the CPU. The waterblock component has been optimised for improved coolant flow, and the entire unit is so compact that it’s incredible to imagine there’s such a quiet pump inside it.
The waterblock is also the hub for the H2O 920’s fan control system, with two 4-pin PWM connectors running out of it for connection to the pair of 120mm Antec fans. There’s also a single 3-pin fan cable, which provides power to the pump, and a USB motherboard header cable, which provides power for the attached cooling fans, as well as data on coolant temperature and fan speeds.
This data is displayed in the bundled Antec Cooling Center software, where you’re able to view and adjust the current coolant temperature, fan speeds and pump speed. There are three configurable fan-speed settings, all of which are based around the coolant temperature rather than the CPU temperature. The Extreme profile runs the fans at full speed, while the Silent profile aims to keep the coolant between 40˚C and 50˚C, spinning up the fans accordingly. Meanwhile, the third Custom profile enables you to set the fans to your own cooling requirements.
Click to enlarge
In a novel addition, the configuration software also enables you to change the colour of the H2O 920’s LED, which is located behind the Antec logo. It’s a neat inclusion, enabling you to match the cooler to your PC’s existing colour scheme.
You install the waterblock via a backplate that utilises modular fittings to accommodate a range of CPU sockets. While the plastic fittings are fiddly to handle, fitting the framework of the mount is straightforward. The waterblock is dropped between the notches of the mount and then twisted into place beneath the mount’s clips, before the mount is fully screwed to the backplate. This simple mounting system is spoiled only by the lack of any extra thermal paste; a small smear, enough for just one installation, is pre-applied to the cooler's contact plate.