Key features
Today I would like to introduce you to the Lumen S28 RGB liquid all-in-one cooler from Fractal Design. This cooler attracts with its discreet and simple design, which can be easily enlivened with RGB LEDs and uses an atypical build with a pump in the radiator. So the question remains whether this solution is an effective enough alternative against conventional AIO coolers with a pump directly in the block, which of course I intend to test in today’s review.
Key features of the cooler
Most of Fractal Design’s products are characterised by Scandinavian minimalism and this one is no different. The cooling block here is pleasingly compact and lightweight, which is of course due to the absence of a pump. Thus, the block serves only as a passive element of the cooler, where the waste heat of the CPU is dissipated through the heat transfer surface of the copper coldplate into the radiator via a liquid.
The top of the cooling block with the manufacturer’s logo serves as a light diffuser for the six RGB LEDs underneath. It can be removed and rotated at 90° intervals to the position that is most visually pleasing to you. This is a small but nice detail.
On the side of the cooling block you will find a connector to connect the cooler to the motherboard using the supplied cable. The manufacturer thus gives you the option of styling the cooler in a minimalist matte black and unobtrusive look without a single cable coming out of the block. Attachment of the tubes to the block is solved with 90° swivel fittings and the tubes are equipped with a protective nylon braid for added durability. A thin layer of thermal paste is applied to the coldplate of the cooler from the factory, so you don’t have to think about the amount of paste or how to apply it.
As mentioned in the previous text, the pump is integrated directly into the radiator. Its position is chosen so that the pump overlaps with the fan motor, thus avoiding unnecessary waste of the radiator’s usable area. This is because the area behind the centre of the fan is a dead space where there is no airflow through the radiator. The cable from the pump is routed through a small notch in the edge of the radiator so that it can be easily hidden and won’t be mechanically damaged during installation. Although the pump cannot be regulated by a PWM signal, it can at least be regulated by voltage. At the end of the radiator, next to the tube fitting, a covered port can be found, which is probably used to fill the radiator in production, but unfortunately it cannot be used to refill the fluid. The radiator is fully maintenance free and no user intervention is expected.
Fortunately, the manufacturer did not skimp on accessories. On the coldplate you will find a layer of thermal paste applied from the factory, in the package there is paste for about three other applications and you will also find an alcohol cleaning cloth for optimal preparation of the heat spreader of the processor. In the accessories you will also find all the necessary components for installing the cooler on the processor, where you just need to choose the installation frame according to your processor socket and the corresponding set of screws. The installation of the cooler is easy and everything is illustrated in the well-designed user manual and you should not encounter any complications during the process.
As is already common practice, for AMD processors you use the native backplate of the motherboard and for Intel processors you use the backplate supplied with the cooler. Of course, there is also a set of 5mm screws to mount the radiator to the computer case or a cable to connect the cooling block lighting to the 5V ARGB connector on the motherboard.
Pump, radiator and fan parameters
Lumen S28 RGB does not stand out from its class of coolers in terms of dimensions. The overall thickness of the aluminum radiator, including the fans, does not exceed 55 millimeters to maximize compatibility with common computer cases, and the cooler is compatible with all current CPU sockets except HEDT. The price is set very reasonably and a nice extra bonus is the five-year warranty.
| Cooler | Fractal Design Lumen S28 RGB | Endorfy Navis F280 | |
| Supported sockets | Intel 115x, 1200, 1700, 20xx; AMD AM4, AM5 | Intel 115x, 1200, 1700, 20xx; AMD AM4, AM5 | |
| Radiator dimensions (H × W × T) | 313 × 140 × 27 mm | 317 × 138 × 28 mm | |
| Block dimensions (H × W × T) | 67 × 79 × 43 mm | 90 × 95 × 48,5 mm | |
| Hose length | 4000 mm | 390 mm | |
| Pump speed | 4000 rpm | 2600 rpm | |
| Radiator material | aluminium | ||
| Max RAM height | no restrictions | ||
| Warranty | 5 years | 3 years | |
| Approx. retail price | 129 EUR | 99 EUR |
The supplied Aspect series fans, like the Lumen S28 RGB cooler block, are equipped with six ARGB LEDs and the cables can be connected in series, which greatly simplifies cable routing and also simplifies motherboard connection without the need for splitters. They’re not bad at all in terms of performance, but paper specifications are unfortunately not comparable between manufacturers and without a unified methodology they don’t have much relevance.
| Fan | Fractal Design Aspect 14 RGB PWM | Endorfy Fluctus 140 PWM | |
| Bearing | rifle | fluid | |
| Max. speed | 1700 rpm | 1800 rpm | |
| Max static pressure | 2.05 mm H2O | N/A | |
| Max. airflow | 132.5 m3/h | N/A |
Today I would like to introduce you to the Lumen S28 RGB liquid all-in-one cooler from Fractal Design. This cooler attracts with its discreet and simple design, which can be easily enlivened with RGB LEDs and uses an atypical build with a pump in the radiator. So the question remains whether this solution is an effective enough alternative against conventional AIO coolers with a pump directly in the block, which of course I intend to test in today’s review.
Measurement methodology
As a test processor and heat generator, I am now using an Intel Core i7-11700K on the Asus TUF Gaming Z590-Plus WiFi motherboard. The entire build is mounted on a Streacom BC1 frame with no fans to provide airflow. Acoustic shielding (acoustic foam on OSB boards) is installed around the test setup to eliminate ambient noise.
The Voltcraft SL-100 calibrated noise meter is placed perpendicular to the cooler in a fixed position relative to the motherboard at a distance of approximately 35 cm from the processor socket. Stress tests are performed using Prime95 with a duration of 30–35 minutes. The coolers are tested at three standardized noise levels (36, 39 and 42 dBA) and finally at maximum speed. The tests are run in two sets according to the heat output of the processor.
The first set of tests is at 125 W, the PL1 processor’s enforced limit. The second set of power draw is then about 205–210 W (4500 MHz at 1.285 V). However, this second level represents a very high concentration of heat per mm² due to the small size of the chip itself. Thus, not all coolers can be expected to pass this set of tests at all noise levels. At the end of the test, the highest temperature achieved is always recorded.
All data regarding CPU temperatures and heat output are obtained from the HWiNFO64 application. The measured values are then corrected against the room temperature as the resulting Delta T value. Any higher value means a processor temperature over 95–100 °C and a risk of thermal throttling. Therefore, if the cooler does not pass the load with a Delta T value below 75 °C, such a test is marked as a failure.
Today I would like to introduce you to the Lumen S28 RGB liquid all-in-one cooler from Fractal Design. This cooler attracts with its discreet and simple design, which can be easily enlivened with RGB LEDs and uses an atypical build with a pump in the radiator. So the question remains whether this solution is an effective enough alternative against conventional AIO coolers with a pump directly in the block, which of course I intend to test in today’s review.
Results – 36 dBA
Unfortunately, I was again unable to get results at 36 dBA. In fact, the radiator pump is slightly noisier than the fans running at minimum speed. The lowest measured noise level of the Lumen S28 RGB cooler was 37.9 dBA when the pump speed was reduced by regulating the voltage to 7 V, because at full power the pump is really noisy. However, it’s pretty much pointless to run it at its maximum, as the differences in cooler effectiveness were minimal whether the pump was running at 12 V or 7 V.
Today I would like to introduce you to the Lumen S28 RGB liquid all-in-one cooler from Fractal Design. This cooler attracts with its discreet and simple design, which can be easily enlivened with RGB LEDs and uses an atypical build with a pump in the radiator. So the question remains whether this solution is an effective enough alternative against conventional AIO coolers with a pump directly in the block, which of course I intend to test in today’s review.
Results – 39 dBA
Today I would like to introduce you to the Lumen S28 RGB liquid all-in-one cooler from Fractal Design. This cooler attracts with its discreet and simple design, which can be easily enlivened with RGB LEDs and uses an atypical build with a pump in the radiator. So the question remains whether this solution is an effective enough alternative against conventional AIO coolers with a pump directly in the block, which of course I intend to test in today’s review.
Results – 42 dBA
Today I would like to introduce you to the Lumen S28 RGB liquid all-in-one cooler from Fractal Design. This cooler attracts with its discreet and simple design, which can be easily enlivened with RGB LEDs and uses an atypical build with a pump in the radiator. So the question remains whether this solution is an effective enough alternative against conventional AIO coolers with a pump directly in the block, which of course I intend to test in today’s review.
Results – 45, 48 and 51 dBA
I tested the Lumen S28 RGB cooler at noise levels of 45, 48 and 51 dBA to better demonstrate the relationship between temperature and noise. The dependency is quite linear and the optimal efficiency ratio at acceptable noise levels is, as usual, somewhere around 40-50% PWM duty cycle for the fans and with the pump at 7V.
Today I would like to introduce you to the Lumen S28 RGB liquid all-in-one cooler from Fractal Design. This cooler attracts with its discreet and simple design, which can be easily enlivened with RGB LEDs and uses an atypical build with a pump in the radiator. So the question remains whether this solution is an effective enough alternative against conventional AIO coolers with a pump directly in the block, which of course I intend to test in today’s review.
Results – maximum speed
Today I would like to introduce you to the Lumen S28 RGB liquid all-in-one cooler from Fractal Design. This cooler attracts with its discreet and simple design, which can be easily enlivened with RGB LEDs and uses an atypical build with a pump in the radiator. So the question remains whether this solution is an effective enough alternative against conventional AIO coolers with a pump directly in the block, which of course I intend to test in today’s review.
Conclusion and evaluation
The Lumen S28 RGB is a visually very nice cooler, which also hides some nice details, such as the rotatable top of the cooling block, the possibility of cable connection in series and extensive accessories. It didn’t fare badly in stress tests at all, and is also affordable and offers an overall good balance of price, effectiveness and neat design. The five-year warranty is also a nice bonus.
However, I will openly admit that my first impressions when testing the Lumen S28 RGB cooler were not the best. In fact, the pump is really noisy at full power and when testing at standardized noise levels I had to noticeably lower the fan speed, which resulted in low cooler effectiveness.
After adjusting the pump to 7 V, the noise dropped significantly and the test results started to make much more sense. The operating optimum of this cooler is therefore with the pump running at 7 V and the fans around 40-50% of the PWM duty cycle. However, apart from this niggle with the pump, I didn’t encounter any major problem with the Lumen S28 RGB cooler, so I can recommend it and give it the Approved editorial award.
English translation and edit by Jozef Dudáš
| Endorfy Navis F360 |
| + Solid effectiveness |
| + Five-year warranty |
| + Attractive design |
| + Affordable price |
| - Noisy pump at full power |
| - The surface of the block is a fingerprint magnet |