EKWB EK-Quantum Surface S240 – Black – 240mm Slim Radiator

Product Overview

The EKWB EK-Quantum Surface S240 – Black is a slim 240mm custom liquid-cooling radiator designed for systems where internal space is limited. At only 30mm thick, it offers an excellent balance of cooling performance, compatibility, and efficient airflow without requiring the additional clearance of thicker radiators.

Featuring a newly optimized radiator core, 16 copper coolant tubes, and high-grade copper fins with a 20 FPI density, the Surface S240 is engineered to perform particularly well at low and medium fan speeds. Its low-restriction design also makes it suitable for custom loops using multiple radiators.

Slim 30mm Design

The Surface S240 is built around a 30mm-thick radiator profile, making it an excellent choice for compact and space-constrained PC cases.

Despite its slim construction, it is designed to provide strong thermal performance at low and medium fan speeds, helping users balance cooling performance with quieter system operation.

New & Improved Radiator Core

The Surface S Series uses a newly developed radiator core with an enhanced fin structure and optimized internal design.

Compared with the previous CoolStream SE, the Surface S radiator delivers up to 20% better core-to-core performance, providing a substantial improvement while maintaining the slim 30mm form factor.

High-Grade Copper Fins & Tubes

The radiator features high-grade non-louvered copper fins with a 20 FPI density, providing a balance between heat transfer and airflow resistance.

Sixteen copper tubes, each measuring 2mm in width, run across the radiator’s length to provide efficient coolant movement while maintaining low restriction within the cooling loop.

Optimized for Low & Medium Fan Speeds

The Surface S240 is designed to deliver effective cooling without requiring aggressive fan speeds.

Its fin structure and radiator core are optimized for low and medium-speed fan operation, making it suitable for builds where acoustic performance is an important consideration.

EK does not recommend a Push/Pull configuration for the S Series, as the additional fans are not expected to provide a proportional increase in performance. For additional cooling capacity, adding another radiator is the preferred approach.

120mm Fan Compatibility

The radiator is designed for 120mm fans with a standard 25mm thickness and includes black M4 Philips round-head screws for installation.

EK recommends EK fans or comparable fans with sealed-edge frames to achieve effective performance in either Push or Pull configurations.

Premium Black Finish

The Surface S240 combines stainless-steel side plates with durable semi-gloss black paint for a clean and premium appearance.

Thick, extruded aluminum end caps feature a contrasting silver finish, covering the radiator internals while adding rigidity to the overall structure. The radiator fins feature a black matte coating designed with thermal performance in mind.

Standardized M4 Screws

The radiator includes hard-wearing black M4 Philips round-head screws for convenient installation.

M4 compatibility also provides flexibility for users who require longer screws in specific configurations. However, EK recommends using the supplied screws whenever possible to minimize the risk of radiator damage.

Easy Disassembly & DIY-Friendly Design

The EK-Quantum Surface range uses a modular construction that makes disassembly straightforward.

This approach provides consistent fitment and appearance across the Surface family while making the radiator suitable for users interested in modifications, painting, and other DIY customization projects.

Low-Restriction Cooling Loop

The Surface S240 is designed with low coolant-flow restriction, reducing unnecessary stress on the pump and allowing multiple radiators to be incorporated into a single loop.

Its low airflow restriction also helps maintain case ventilation and enables the radiator to perform effectively at lower fan speeds. It can be integrated into systems powered by D5 or DDC pumps.

EK-Matrix7 Compatible

The Surface S240 is fully EK-Matrix7 compatible, using standardized product dimensions and port positioning to simplify custom-loop planning.

Matrix7 compatibility allows the radiator to integrate with compatible EK components, including Reflection² distro plates, while making clean and parallel tube runs easier to achieve.

Users can also swap between S, P, and X Series Surface radiators when the case provides sufficient clearance for the selected radiator thickness.

TechPowerUp Editor’s Choice

The EK-Quantum Surface S radiator series received the Editor’s Choice award from TechPowerUp.

The award recognized the series for its value, broad case compatibility, thermal performance for its form factor, low coolant-flow restriction, available color options, and mod-friendly construction.

Technical Specifications

Ideal For

• Space-constrained PC cases
• Slim 240mm custom water-cooling builds
• Gaming PCs with limited radiator clearance
• Low-noise liquid-cooling systems
• Low and medium fan-speed configurations
• Multi-radiator custom loops
• D5 or DDC pump-based systems
• EK-Matrix7 custom-loop builds
• Black-themed gaming and workstation PCs
• DIY PC modding enthusiasts