Fractal Design Lumen S28 Introduction

We have tested the Fractal Design Lumen S24 RGB and Lumen S36 RGB earlier. Both coolers pack a performance punch. This time we are completing the series by testing the Lumen S28 [Non-RGB] version. As mentioned earlier, Fractal is using APALTEK as the OEM of the Lumen series coolers. The fans are non-RGB but the block still features the same stunning A-RGB lighting as we have seen on the other models in the Lumen series.

The salient features are:

  • Integrated ARGB effects with full motherboard control
  • The removable pump face can be turned at 90-degree intervals to maintain a horizontal logotype in
  • any mounting orientation
  • Asus AURA, Gigabyte Fusion, MSI Mystic Light, Razer Chroma, and ASRock Polychrome support
  • Pre-applied thermal paste for optimal application with even coverage
  • Supports the most common sockets for both Intel and AMD
  • Durable low-permeability rubber tubing with nylon braided sleeves
  • Articulating elbow fittings make tubes easier to route and reduce tension on the pump
  • Low turbulence Fractal Design Aspect 14 PWM fans with chainable power
  • Backed by a 5-year warranty

Item:                                     Fractal Lumen S28

Manufacturer:                    Fractal Design

Price:                                    Euro/US $ 109.99 MSRP



Specs 5 Fan Specs Rad Specs


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The cooler is shipped inside Fractal themed box. Let’s take a look at what is provided in the box.

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  • 1x Comprehensive User Manual
  • 1x Brochure on how to contact the manufacturer in case of receiving a faulty product.

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  • 1x Intel Backplate
  • 1x AMD Ring Bracket
  • 1x Intel Ring Bracket [Comes pre-installed on the block]

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  • 4x Thumb Nuts
  • 4x Black Spacers
  • 4x Intel LGA20xx Standoffs
  • 4x Intel other sockets Standoffs
  • 5x Washers
  • 2x AMD Mounting Brackets (Pins)

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  • 8x Philips 6-32 Long Screws
  • 8x Philips 6-32 Short Screws

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1x Cable is provided which connects the block of the cooler with the standard 3-pin A-RGB header (5V) header on the motherboard.

Fractal Design Lumen S28 Closer Look

It is time to take a closer look at the components. Before that here is what Fractal Design is saying about the cooler. “The new Lumen series of AIO CPU coolers from Fractal Design delivers high-end cooling performance and premium ARGB effects at an attractive price. Lumen features Fractal Design’s newly released Aspect PWM fans with daisy-chainable power/ARGB connectors and comes pre-applied with optimal thermal paste coverage, making it an attractive AIO solution for both starting and seasoned builders. Options for controlling the pump’s integrated ARGB effects include Asus AURA, Gigabyte Fusion, MSI Mystic Light, Razer Chroma, and ASRock Polychrome support. 240mm, 280mm, and 360mm radiator sizes are available with a choice of ARGB or all-black Aspect fans, and all versions include mounting hardware for all the most common AMD and Intel CPUs as well as a 5-year limited warranty.”

The cooler is compatible with Intel LGA20xx/1366/1200/115x sockets and AMD AM4/AM3+/AM3/AM2+/AM2/FM2+/FM2/FM1 sockets. We have yet to hear about the LGA17xx upgrade kit from Fractal Design. The Fractal Design Lumen S28 is a 280mm CLC cooling solution. It has a 280mm radiator with 2x Aspect 14 PWM fans.

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The dimension of the radiator is 312 x 140 x 27mm. The thickness of the radiator is 27mm. With 25mm fans, the overall thickness would be 52~53mm. The radiator has 20 fins per inch (FPI). There is a gap of 105mm between any two fan mounting holes on the radiator. The distance between the middle two mounting holes is 15mm and the distance from the outermost mounting hole to the far head is 20mm. Similarly, the distance between the uttermost mounting holes to the near head is 27mm. Fin stack is dense and taking into account the left and right side channels, it has a total of 12 channels for water flow. The fan screw threads rating is 6-32.

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The radiator is made of aluminum hence it is lightweight. This is an APALTEK design. The blocks on both ends of the radiator are not rectangular and have rounded edges.

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We have a nice and clean fins stack.

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Unlike the Celcius+ series, the Lumen series radiators don’t have protective plating under the fin stack which would prevent the screws from damaging the fins.

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There is a Fractal Design branding the sides of the radiator housing.

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The build quality of the cooler is top-notch, all around. Fractal Design is using barbed fittings on the radiator with large size couplings. There is a sticker pasted here showing the serial no of the unit. There is what seems to be the drain port or something. It is reserved for factory use only and opening it might lose the vacuum pressure in the loop.

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The Fractal Design is using low-permeability rubber tubes. These tubes run to approximately 400mm in length and have a braided nylon sleeves on them.

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Unlike the Celcius+ series coolers, the Lumen coolers don’t have a PWM/ARGB hub on the radiator. But there is one key difference here. The Pump is installed on the radiator instead. I think NZXT was the one who launched a similar design back in time. Here is some data pertaining to the pump:

Rotational Speed 4000 ±10% RPM
Bearing Ceramic
PWM Control No
Noise at full speed 22 dBA
Maximum pressure, 50°C 2.5 PSI
Rated Voltage 12VDC
Rated Input Current 0.34A
Rated Input Power 4.08W
MTTF 50,000 Hours
ARGB Cable Length 500mm

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There is a 3-pin cable coming out of the pump. It has a length of 775mm which is plentiful to reach the desired control source even if the radiator is mounted on the front of the PC case.

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The routing of the pump power cable has been done wisely. There are two cutouts on the sides of the housing of the radiator. The cable can either be routed through these cutouts for neat cable management.

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The block of the cooler is lightweight which makes sense as we only have a cold plate, chambers for the coolant flow, and a top cover with 6 A-RGB LEDs under it. The dimension of the block is 79x67x43mm where 43mm is the height of the block and 67mm is the diameter. The dimension is inclusive of the tube fittings.

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The top cover is not in a solid color and there is a reason for that. It is translucent with supported PCB and A-RGB LEDs on the PCB. The top cover is removable and can be placed in 90° rotations which make the installation of the block irrespective of the logo.

The above pictures show the top cover placed in three angles besides the default location.

The main housing of the block is in matte black. Notice the spacing below the housing and above the base. This is where the Intel/AMD mounting rings are slid in.

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Fractal Design is using articulating 90° elbow fittings on the block. This makes the rotation of the tubes easier and reduces the tension on the pump. The machining and milling are right on the money.

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There is a 3-pin header on the side of the main housing. This is where the provided 3-pin ARGB cable is connected to power the ARGB LEDs.

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We have a copper base with pre-applied thermal paste. We are not testing the cooling solution on stock paste as our standard thermal paste is Noctua NT-H1.

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The Lumen S28 comes with 2x Aspect 14 PWM fans. These are high airflow and static pressure optimized fans. Each fan has 7 black color blades with optimized fan geometry balancing the airflow with extra emphasis on static pressure. Here are key features of the fans:

  • Efficient rifle bearings with 90,000 hour MTTF
  • Aerodynamic stator with embedded wiring reduces turbulence
  • Trip Wire technology introduces a micro-turbulent layer for enhanced blade efficiency
  • Daisy chainable power for easy hookup
  • PWM control with a wide speed range
  • High static pressure is ideal for radiators and airflow-restrictive applications

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There is Fractal Design branding on one side.

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The backside of the fan shows the 4-arms assembly on the mainframe with one arm having an inset. The wires are routed on this arm towards the exterior of the fan. There is a Fractal Design branding on the sticker in the center.

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The fans have a 4-pin PWM connector and header/socket. The cables are flat in design.

Installation and Clearance

The cooler is tested on the Intel LGA1200 socket using the MSI MAG Z490 TOMAHAWK motherboard. The installation is convenient and it includes 13 items to install the block on the motherboard. We are no longer covering the details of the installation. Please check the installation guide provided with the cooler for quick help.

There is no clearance issue with respect to the DIMM slots and first PCIe slot. Make sure your chassis has clearance for a 280mm radiator (with a total length of 312mm).

Digital Lighting

The A-RGB lighting in the block is compatible with:


Here are a few pictures:

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Fractal Design Lumen S28 Testing

The following test configuration is used: –

  • Intel i7 10700k
  • T-Force NightHawk RGB 16GB @ 3200MHz
  • Nvidia GeForce GTX 1080 FE
  • addlink S70 256GB NVMe SSD
  • be quiet! Straight Power 11 850W Platinum PSU
  • Thermaltake Core P6 TG Snow Edition in an open frame layout

Here is the settings table for testing:

Clock (MHz) 3800 All Cores
Voltage (V) 1.025
Clock (MHz) 5000 All Cores
Voltage (V) 1.325
Turbo Boost Disabled
C-States Disabled
Speed Step Disabled
Thermal Paste Noctua NT-H1
Thermal Paste Application Dot Method in the center.
Test Run Time 30 minutes
Idling Time 10 minutes
Fan Speed 100% PWM Duty Cycle and Auto PWM
Pump Speed Connected to the AIO Pump header to run at 100% speed
Header CPU_Fan header for the fans and Pump_Header for the pump
Software AIDA64 6.3 Extreme [FPU]


We are using Noctua NT-H1 thermal paste for testing. Using the same thermal paste for all coolers would ensure standardization. Delta temperatures are reported on the graphs. The testing is done on an open-air bench system. Once inside the chassis, the temperatures are expected to rise and would largely depend upon the optimal airflow inside the chassis.

Not every run of the stress test may yield the same result. This could well be due to many factors like mounting pressure, thermal paste application, varying ambient temperature. Not to mention the silicon differences even among the same category of chips. Hence, it is pertinent to mention the testing methodology along with the specifics.


Let’s take a look at the results.

3.8GHz All Cores


5.0GHz All Cores


The Lumen S28 packs a solid performance punch and it can take the fight to a few 360mm AIOs as well.


The sound meter was showing the noise level to be 49 dB(A) with an ambient sound level of 33 dB(A).



Lumen is the new series of AIO coolers from the Fractal Design using APALTEK as OEM. The new series has two categories of coolers. One is RGB and the other is non-RGB. These coolers are available in 240mm, 280mm, and 360mm size in both categories. Another keynote is the launch of new Aspect series fans from Fractal Design in 120mm and 140mm sizes in black and white colors. The Lumen coolers take full advantage of Aspect fans as they feature Aspect 12/14 RGB PWM fans in Lumen S RGB coolers and non-RGB Aspect fans in the Lumen S RGB coolers.

We have tested the Lumen S24 RGB and S36 RGB earlier. This time we have tested the Lumen S28 completing the Lumen series. The Lumen S28 has wide socket compatibility as it supports Intel LGA/1366/115x/1200/20xx sockets and AMD AM4/AM3+/AM3/AM2+/AM2/FM2+/FM2/FM1 sockets. We have yet to hear about the LGA17xx mounting kit from Fractal Design.

The unit has an aluminum radiator measuring 312 x 140 x 27mm. It is black color spray painted. The thickness of the radiator is 27mm. The overall thickness would be 52~53mm after installing the fans. The radiator has 20 FPI. The Fractal Design is using low-permeability rubber tubes running to approximately 400mm in length and has a braided nylon sleeve on them. The radiator does not have a protective plating under each mounting hole for safety measures.

Another striking difference in this new series over the previous series is the lack of an integrated fan/RGB hub on the radiator. The pump on Lumen S28 has been integrated into the radiator. Fractal Design was paying close attention as they have provided purpose-built cutouts on the housing of the radiator on both sides through which the user can route the power cable coming from the pump. The pump takes power from a 3-pin connector. The pump has a ceramic shaft and bearing with a pressure rating of 2.5 PSI at 50°C. It has a life expectancy of 50,000 hours which is permeation dependent.

The block has a circular shape and is quite lightweight. The top cover serves the Duality design. We have an almost brown-colored top cover which is in fact translucent. There are 6 ARGB LEDs underneath which illuminates the complete top in one heck of an AURA show. The top cover is also removable and can be placed at 90° angles. This makes the placement of the block independent of the brand logo’s orientation. There is a detachable ARGB cable provided in the box which the user can connect to the block and the other end to the 5V, 3-pin header on the motherboard.

The Lumen S28 comes with two Aspect 14 PWM fans. These are high airflow and static pressure optimized fans for optimal cooling performance out of the box. They are rated for up to 1700 RPM with an airflow rating of 78 CFM and a 2.05 mmH₂O pressure rating. They have a life expectancy of 90,000 hours using Rifle bearings.

The installation is convenient and we have to deal with 13 items to install the block on the motherboard. Since the Lumen S28 cooler is using the provision of a socket on the cable, the user can easily chain the fans so that the speed of the fans can be controlled from a single source. Please note that there is no dedicated controller provided in the box for digital lighting on the block but to that end, Fractal is using a standard 3-pin, 5V interface cable so it should not be an issue hooking it up with the compatible motherboard.

The Fractal Design Lumen S28 is listed at US $/Euro 109.99 MSRP at the time of the review. This is the same price tag we have seen on the Lumen S24 RGB. The key differences would be A-RGB fans vs non-RGB fans and the 240mm radiator vs 280mm radiator. Fractal Design is offering a 5-year warranty.

The Lumen S28 has shown a fantastic performance offering a nice blend of features in this price range, with better thermal performance and noise output. The only thing lacking would be A-RGB fans which is more of a personal preference and the user can go with the Lumen S28 RGB version which would US $/Euro 119.99. The cooler comes recommended by us.

Thanks to Fractal Design for the provision of Lumen S28.

EnosTech Recommended Award