The Liquid Cooling Glossary

The article aims to give insight into the most important phrases, expressions, acronyms, abbreviations, portmanteaus, and other important pieces of lingo commonly used in the computer liquid cooling community.

The Liquid Cooling Glossary

A | B | C | D | E | F | G | H | I | J | L | M | N | O | P | Q | R | S | T | V | X | Y

A

ABS: Acrylonitrile butadiene styrene is a common and popular mold injection material in the liquid cooling industry.

Acetal: Durable technical plastic, also known as POM, a popular material in the liquid cooling industry. See What is the difference between acetal and Plexi?

ACF: EK's Advanced Compression Fitting. It comes in many varieties and doesn't need any clamps to secure the tubing.

Acrylic: Polymethyl methacrylate (PMMA). See Plexi.

Airflow: Airflow is a movement of air, usually generated by any form of a fan. The higher the airflow, the better the performance.

Airflow Fan: See Case Fan.

Artifacts: Graphical anomalies, usually caused by physical damage or unstable GPU or RAM IC overclocks. See Water-cooled video card crashes?

B

Bow: Refers to the water block’s curvature of the contact surface, usually in reference to CPU blocks). The bow angle and type (concave/convex) can be changed depending on the application and is intentionally designed as such. 

Block: The water block or cold head/plate is the part of the liquid cooling loop which draws the heat from PC components.

Bridge: A term typically associated with connecting multiple GPU water blocks (i.e. Full Cover) together using a single manifold. EK uses two different types. 

C

Case Fan: A cooling fan intended for PC chassis ventilation. Built for high airflow but does not generate much static pressure. Not recommended for radiator cooling.

CC: Short for Cooling Configurator, EK's renowned compatibility database system that helps you choose the right EK products for your hardware to avoid compatibility issues. The configurator recommends compatible EK products from our database in accordance with the hardware you select (motherboard, GPU, SSD). 

Chipset: A term that denotes the motherboard's main logic, originally consisting of South Bridge and North Bridge. On most modern motherboards, North Bridge is integrated into the CPU. See NB and SB.

CNC: Computerized Numeric Control. It typically refers to CNC mills, the primary machining tool used to create products.

Combo (Unit): A combined unit that features a pump and a reservoir within the same assembly. Sometimes called "pump/res combo."

Coolant: A heat-removing liquid used in liquid cooling systems. Typically a mixture of corrosion/algae inhibiting chemicals and distilled water.

Conductivity: A term denoting electrical conductivity of the liquid cooling medium (coolant). Coolants have very low electrical conductivity.

Corrosion: The gradual destruction of (dissimilar) metals by chemical reaction with their environment. It can be effectively inhibited using coolants.

CPU: Central Processing Unit; the main microprocessor of the computer.

CSQ: The Circle SQuare design by EK, introduced in 2012. Its radical approach stirred a lot of hell but was still loved by many. Full Cover CSQ blocks (now called Original CSQ) use EK-FC Bridge CSQ system, for example. Modders love to polish these! 

D

D5: A renowned cylindrical high-flow liquid cooling pump from Laing/Xylem. Quiet and powerful.

DBAY: A dual 5.25" drive bay slot occupying reservoir or pump/reservoir combo unit.

DDC: A high-pressure liquid cooling pump from Laing/Xylem. It is square-shaped and quite tiny but very powerful.

Delid / De-lid: A process of removing the microprocessor's integrated heat spreader (IHS) to obtain better cooling performance by improving the heat transfer. See My CPU is overheating!

Delrin: Commercial trade name for POM. See Acetal.

Delta / Delta T: The difference between two temperature readouts; usually stands for the temperature difference between ambient and liquid (water) temperature. The lower the delta, the better the cooling system.

E

EK-CEO: The Boss, much like Bruce Springsteen. Overly-enthusiastic about his new forum role. Soon to be regretting it.

EPDM: A type of high-quality industrial grade rubber used in EK ZMT tubing. See ZMT.

F

Fan Bearing: A machine element that constrains relative motion to only the desired motion and reduces friction between the moving parts. Ball bearing is more audible in operation than sleeve bearing but much more durable and reliable.

Fill Port: Optional loop component for easier filling and emptying of the liquid cooling system. Personal taste.

Flux: Pre-soldering surface treatment/cleaning agent, usually found in radiators.

Full Board: A motherboard water block (kit) that cools all vital parts of this component - VRM, SB/PCH, and NB (if present).

Full Copper / Full Nickel: A term used by EK to describe a water block that is entirely made of copper and copper alloys. Typically, flagship-performance CPU blocks are Full Copper / Full Nickel.

Full Cover: A graphics card water block that cools the GPU, RAM IC, and the VRM. There are also variants that cool the GPU and RAM IC only.

G

Glycol (ethylene and propylene): Corrosion inhibiting additives found in coolants. Very effective against algae growth. Since ethylene glycol is very toxic, it is mixed with detox additives in modern coolants.

Goofy (orientation): A term invented by the community to describe the rotated (90° clock-wise) installation orientation of the CPU water block.

GPU: Stands for Graphics Processing Unit, the processor within the graphics card. Commonly (but incorrectly) used to refer to an entire graphics/video card.

Gunk: A thick build-up of unknown origin sometimes found in liquid cooling loops. It typically consists of debris, insoluble chemicals, and/or organic growth.

H

HFB: EK's High Flow Barbs fitting. It comes in many variants and requires a hose clamp or an adequate substitute for the safest operation.

I

IHS: Integrated Heat Spreader; usually a plated copper cover plate that protects microprocessors from (spot) overheating. It can be soldered or glued to the microprocessor.

Insert: Part of Supremacy EVO/MX CPU water block internal flow streamer. There are different inserts optimized for different CPU platforms.

IX: Indigo Xtreme, a renowned phase change alloy TIM.

J

Jet (Plate): A nozzle within a water block that increases liquid flow velocity to further aid cooling performance.

L

Loop: Short for liquid cooling loop/circuit, typically consisting of a water block, radiator (with fan), pump, and reservoir.

M

Monoblock: An all-in-one motherboard water block that cools the CPU, VRM, and PCH (SB). It requires minimal effort to run when compared to the traditional multi-block arrangement.

Mounting plate: A hold-down plate specific for each CPU socket or GPU hole spacing pattern. Exchangeable mounting plates allow the same water block to fit different platforms.

Mosfet: A field-emitting transistor and a crucial part of VRM. It also stands for motherboard VRM water blocks (i.e., "a MOSFET block").

N

NB: Stands for North Bridge and is a part of the motherboard's chipset that also has an SB (South Bridge) part. Modern motherboards do not have NB but rather a PCH (as NB is integrated into the CPU). See SB and Chipset. 

Neoprene: High-quality industrial-grade synthetic CR rubber. It is sometimes (but rarely) used for tubing.

Nickel (plating): A fine, thin layer of electrolytically deposited nickel on the bare copper base. It improves the component's aesthetics and prevents copper tarnishing. 

Norprene: High-quality industrial-grade synthetic rubber. It provides a notch better chemical resistance than EPDM but is quite expensive.

O

Oxidation: Naturally occurring reaction between metal and oxygen in the presence of water or air moisture. Practically impossible to prevent. Not to be mistaken with corrosion.

P

Parallel: Describes the liquid flow distribution. In a parallel connection, every liquid cooling block receives only a portion of the total flow rate. Not recommended for blocks with dissimilar pressure drop characteristics. Large parallel flow loops may result in low partial flow rates through water blocks.

PCH: Platform Controller Hub is an Intel term for the chipset of a motherboard. Also known as SB.

Plasticizer: See What is plasticizer?

Plexi: Translucent acrylic glass material, a popular choice in the liquid cooling industry. See What is the difference between acetal and Plexi?

Plug: A threaded plug used to close unused ports on the liquid cooling gear.

POM: Polyoxymethylene. See Acetal.

Pressure (head): The maximum pumping height of a liquid cooling pump with no flow is not achievable under normal circumstances. The higher the value, the more suitable the pump for a big liquid cooling loop with water blocks in serial connection.

Pressure drop: The hydraulic pressure difference between a cooling component's input and output. The higher the flow rates, the higher the pressure drop. Pressure drop is a function of restriction due to differences in general construction.

PETG: Polyethylene Terephthalate Glycol. A plastic material that is a popular choice for hard (solid) tubing, an alternative to Acrylic.

PVC: Polyvinyl Chloride, with the addition of plasticizers; a popular material for soft translucent tubing. See Plasticizer and Tubing.

PWM: Pulse-Width Modulation, modern duty cycle control that allows fans and pumps to perform on demand. Unlike voltage control, PWM control actually lowers power draw.

R

Rad: Short for a liquid cooling radiator.

Radiator Fan (or Rad Fan): A cooling fan intended for cooling radiators (i.e., Vardar), also known as a High Static Pressure Fan. It generates high static pressure but produces less airflow. Not ideal for chassis ventilation (see Case Fan).

Raddage: A term to denote the general amount of radiator surface (cooling) area. See What size radiator do I need for my system?

Res: Short for the reservoir.

RAM IC: Memory chips found on graphics cards or standalone memory modules.

Q

QDC: Quick DisConnect fitting; allows disconnecting parts of the loop for replacement or maintenance purposes without draining the coolant.

S

SB: South Bridge and North Bridge are parts of the motherboard's chipset. The SB portion carries USB, SATA, and other periphery controllers. See PCH and NB.

SBAY: A single 5.25" drive bay slot occupying a reservoir or a pump/reservoir combo unit.

Serial: Describes the liquid flow distribution. In serial connection, every liquid cooling block has the same flow rate. Large serial flow loops may result in a big pressure drop.

Soon™: A term EK uses to reassure its customers about overdue release dates.

Standoff: A metallic threaded spacer used to prevent over-tightening and subsequent damage to the computer hardware, mostly motherboards and graphics cards.

Static Pressure: Pressure generated by the cooling fan at zero flow conditions. Liquid cooling radiators operate best when combined with high static pressure fans.

Static Pressure Fan: See Radiator Fan.

T

Tarnishing: A term usually associated with copper and brass surfaces changing hue and turning dark. See Oxidation.

Temp(s): Short for temperature (example: "what are your temps?")

TIM: Thermal Interface Material or thermal grease. Used to improve thermal contact between water blocks and microprocessors.

Tubing: The hose through which the cooling medium (coolant) is transferred from one liquid cooling loop component to another. It comes in many sizes, colors, and materials. See PVC and EPDM.

V

VRM: Voltage Regulation Module is a computer component power delivery system. It usually requires active cooling, especially on modern high-power graphics cards. See Mosfet.

X

XRES: EK improved volute liquid cooling pump with an integrated reservoir. A combo unit (Pump + Res) for less hassle. See Res and Pump.

XTOP: EK improved volute liquid cooling pump. Comes with functionally improved housing and mounting. It provides more performance and easier handling than factory pumps.

Z

ZMT: Stands for Zero Maintenance Tubing. EPDM matte black industrial grade tubing, which contains no plasticizer. Zero Maintenance Tubing. See EPDM and Plasticizer.