A water block is the

watercooling Cooling tower and water discharge of a nuclear power plant Water cooling is a method of heat removal from components and industrial equipment. Evaporative cooling using water is often more efficient than air cooling. Water is inexpensive and non ...

equivalent of a

heatsink A heat sink (also commonly spelled heatsink) is a passive heat exchanger that transfers the heat generated by an electronic or a mechanical device to a fluid medium, often air or a liquid coolant, where it is dissipated away from the device, ...

. It is a type of

plate heat exchanger A plate heat exchanger is a type of heat exchanger that uses metal plates to transfer heat between two fluids. This has a major advantage over a conventional heat exchanger in that the fluids are exposed to a much larger surface area because the f ...

and can be used on many different computer components, including the

central processing unit A central processing unit (CPU), also called a central processor, main processor, or just processor, is the primary Processor (computing), processor in a given computer. Its electronic circuitry executes Instruction (computing), instructions ...

(CPU),

GPU A graphics processing unit (GPU) is a specialized electronic circuit designed for digital image processing and to accelerate computer graphics, being present either as a discrete video card or embedded on motherboards, mobile phones, personal ...

, PPU, and northbridge chipset on the motherboard. There are also Monoblocks on the market that are mounted on PC motherboards and cover the CPU and its power delivery VRMs (Voltage Regulator Modules) that surround the CPU socket area. It consists of at least two main parts; the "base", which is the area that makes contact with the device being cooled and is usually manufactured from metals with high thermal conductivity such as

aluminum Aluminium (or aluminum in North American English) is a chemical element; it has chemical symbol, symbol Al and atomic number 13. It has a density lower than that of other common metals, about one-third that of steel. Aluminium has ...

copper Copper is a chemical element; it has symbol Cu (from Latin ) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkish-orang ...

. The second part, the "top" ensures the water is contained safely inside the water block and has connections that allow hosing to connect it with the

water cooling file:KKP Auslauf.jpg, Cooling tower and water discharge of a nuclear power plant Water cooling is a method of heat removal from components and industrial equipment. Evaporative cooling using water is often more efficient than air cooling. Water i ...

loop. The top can be made of the same metal as the base, transparent

Perspex Poly(methyl methacrylate) (PMMA) is a synthetic polymer derived from methyl methacrylate. It is a transparent thermoplastic, used as an engineering plastic. PMMA is also known as acrylic, acrylic glass, as well as by the trade names and bran ...

Delrin Polyoxymethylene (POM), also known as acetal, polyacetal, and polyformaldehyde, is an engineering thermoplastic used in precision parts requiring high stiffness, low friction, and excellent dimensional stability. Short-chained POM (chain length ...

Nylon Nylon is a family of synthetic polymers characterised by amide linkages, typically connecting aliphatic or Polyamide#Classification, semi-aromatic groups. Nylons are generally brownish in color and can possess a soft texture, with some varieti ...

, or

HDPE High-density polyethylene (HDPE) or polyethylene high-density (PEHD) is a thermoplastic polymer produced from the monomer ethylene. It is sometimes called "alkathene" or " polythene" when used for HDPE pipes. With a high strength-to-density ratio ...

. Most newer high-end water blocks also contain mid-plates which serve to add jet tubes, nozzles, and other flow altering devices. The base, top, and mid-plate(s) are sealed together to form a "block" with some sort of path for water to flow through. The ends of the path have inlet/outlet connectors for the tubing that connects it to the rest of the watercooling system. Early designs included

spiral In mathematics, a spiral is a curve which emanates from a point, moving further away as it revolves around the point. It is a subtype of whorled patterns, a broad group that also includes concentric objects. Two-dimensional A two-dimension ...

, zig-zag pattern or

like fins to allow the largest possible surface area for heat to transfer from the device being cooled to the water. These designs generally were used because the conjecture was that maximum flow was required for high performance. Trial and error and the evolution of water block design has shown that trading flow for

turbulence In fluid dynamics, turbulence or turbulent flow is fluid motion characterized by chaotic changes in pressure and flow velocity. It is in contrast to laminar flow, which occurs when a fluid flows in parallel layers with no disruption between ...

can often improve performance. The Storm series of water blocks is an example of this. Its jet tube mid plate and cupped base design makes it more restrictive to the flow of water than early maze designs but the increased turbulence results in a large increase in performance. Newer designs include "pin" style blocks, "jet cup" blocks, further refined maze designs, micro-fin designs, and variations on these designs. Increasingly restrictive designs have only been possible because of increases in maximum head pressure of commercially viable water

pump A pump is a device that moves fluids (liquids or gases), or sometimes Slurry, slurries, by mechanical action, typically converted from electrical energy into hydraulic or pneumatic energy. Mechanical pumps serve in a wide range of application ...

s. A water block is better at dissipating heat than an

air-cooled Air-cooled engines rely on the circulation of air directly over heat dissipation fins or hot areas of the engine to cool them in order to keep the engine within operating temperatures. Air-cooled designs are far simpler than their liquid-cooled ...

heatsink due to water's higher

specific heat capacity In thermodynamics, the specific heat capacity (symbol ) of a substance is the amount of heat that must be added to one unit of mass of the substance in order to cause an increase of one unit in temperature. It is also referred to as massic heat ...

and

thermal conductivity The thermal conductivity of a material is a measure of its ability to heat conduction, conduct heat. It is commonly denoted by k, \lambda, or \kappa and is measured in W·m−1·K−1. Heat transfer occurs at a lower rate in materials of low ...

. The water is usually pumped through to a

radiator A radiator is a heat exchanger used to transfer thermal energy from one medium to another for the purpose of cooling and heating. The majority of radiators are constructed to function in cars, buildings, and electronics. A radiator is always a ...

which allows a fan pushing air through it to take the heat created from the device and expel it into the air. A radiator is more efficient than a standard CPU or GPU heatsink/air cooler at removing heat because it has a much larger surface area. Installation of a water block is also similar to that of a heatsink, with a thermal pad or

thermal grease Thermal paste (also called thermal compound, thermal grease, thermal interface material (TIM), thermal gel, heat paste, heat sink compound, heat sink paste or CPU grease) is a Thermal conductivity, thermally conductive (but usually not Insula ...

placed between it and the device being cooled to aid in

heat conduction Thermal conduction is the diffusion of thermal energy (heat) within one material or between materials in contact. The higher temperature object has molecules with more kinetic energy; collisions between molecules distributes this kinetic energy u ...

References

{{reflist Computer hardware cooling Heat exchangers