Water cooling: Difference between revisions

Water cooling is commonly used for cooling automobile [[internal combustion engine]]s and [[power stations]]. Water coolers utilising [[Convection (heat transfer)|convective heat transfer]] are used inside high-end [[personal computers]] to lower the temperature of [[CPU]]s and other components.

Water is inexpensive, [[non-toxic]], and available over most of the earth's surface. Liquid cooling offers higher thermal conductivity than air cooling. Water has unusually high specific heat capacity among commonly available liquids at room temperature and atmospheric pressure allowing efficient heat transfer over distance with low rates of mass transfer. Cooling water may be recycled through a ''recirculating'' system or used in a single -pass ''once-through cooling'' (OTC) system. Water's high [[enthalpy of vaporization]] allows the option of efficient evaporative cooling to remove waste heat in [[cooling tower]]s or [[cooling pond]]s.{{sfnp|Kemmer|1979|pages=1-1, 1-2}} Recirculating systems may beare ''open'' if they rely upon evaporative cooling or ''closed'' if heat removal is accomplished in [[heat exchanger]]s, thus with negligible evaporative loss. A heat exchanger or [[Condenser (heat transfer)|condenser]] may separate ''non-contact cooling water'' from a [[fluid]] being cooled,{{sfnp|Kemmer|1979|pages=38-1, 38-4, 38-7 & 38-8 }} or ''contact cooling water'' may directly impinge on items like [[saw]] blades where [[phase (matter)|phase]] difference allows easy [[phase separation|separation]]. Environmental regulations emphasize the reduced concentrations of waste products in non-contact cooling water.{{sfnp|King|1995|pages=143, 439}}

Water accelerates the corrosion of metal parts and is a favorable medium for biological growth. Dissolved minerals in natural water supplies are concentrated by evaporation to leave deposits called scale. Cooling water often requires the addition of chemicals to minimize corrosion and insulating deposits of scale and biofouling.{{sfn|Betz|pages=183–184}}

Water contains varying amounts of impurities from contact with the atmosphere, soil, and containers. ManufacturedBeing metalsboth tendan toelectrical revertconductor toand oresa viasolvent electrochemicalfor reactionsmetal ofions corrosion.and Wateroxygen, water can accelerate corrosion of machinery being cooled as both an electrical conductor and solvent for metal ions and oxygen. Corrosion reactions proceed more rapidly as temperature increases.{{sfn|Betz|pages=183–184}} Preservation of machinery in the presence of hot water has been improved by addition of [[corrosion inhibitor]]s including [[zinc]], [[chromates]] and [[phosphates]].<ref>{{Cite journal|last=Hemmasian-Ettefagh|first=Ali|date=2010|title=Corrosion Inhibition of Carbon Steel in Cooling Water|journal=Materials Performance|volume=49|pages=60–65}}</ref><ref>{{Cite journal|lastlast1=Mahgoub|firstfirst1=F.M.|last2=Abdel-Nabey|first2=B.A.|last3=El-Samadisy|first3=Y.A.|date=March 2010|title=Adopting a multipurpose inhibitor to control corrosion of ferrous alloys in cooling water systems|journal=Materials Chemistry and Physics|volume=120|issue=1|pages=104–108|doi=10.1016/j.matchemphys.2009.10.028|issn=0254-0584}}</ref> The first two have toxicity concerns;{{sfnp|Kemmer|1979|pages=38-20, 38-21}} and the last has been associated with [[eutrophication]].{{sfnp|Goldman|Horne|1983|pages=153, 160}} Residual concentrations of biocides and corrosion inhibitors are of potential concern for OTC and blowdown from open recirculating cooling water systems.{{sfn|Betz|page=215}} With the exception of machines with short design life, closed recirculating systems require periodic cooling -water treatment or replacement raising similar concern about ultimate disposal of cooling water containing chemicals used with environmental safety assumptions of a closed system.<ref>{{cite web |url=https://www.greenmatters.com/p/how-to-dispose-of-antifreeze |title=How to Properly and Safely Dispose of Antifreeze |last=Krosofsky |first=Andrew |website= |date=18 January 2021 |publisher=Green Matters |accessdate=23 June 2021 }}</ref>

[[Biofouling]] occurs because water is a favorable environment for many life forms. Flow characteristics of recirculating cooling water systems encourage colonization by [[Sessility (zoology)|sessile]] organisms to useusing the circulating supply of food, [[oxygen]] and nutrients.{{sfnp|Reid|1961|pages=267–268}} Temperatures may become high enough to support [[thermophilic]] populations of organisms such as types of [[fungi]].<ref name="Jones1969">{{cite journal |last1=Jones |first1=E.B.G. |last2=Eaton |first2=R.A. |title=''Savoryella lignicola'' gen. et sp. nov. from water cooling towers. |journal=Transactions of the British Mycological Society |date=1969 |volume=52 |pages=161–174|doi=10.1016/S0007-1536(69)80169-5 }}</ref> Biofouling of heat exchange surfaces can reduce heat transfer rates of the cooling system;, and biofouling of cooling towers can alter flow distribution to reduce evaporative cooling rates. Biofouling may also create differential oxygen concentrations increasing corrosion rates. OTC and open recirculating systems are mostmore susceptible to biofouling. Biofouling may be inhibited by temporary habitat modifications. Temperature differences may discourage the establishment of thermophilic populations in intermittently operated facilities;, and intentional short -term temperature spikes may periodically kill less tolerant populations. [[Biocide]]s have been commonly used to control biofouling where sustained facility operation is required.{{sfn|Betz|page=202}}

[[Chlorine]] may be added in the form of [[hypochlorite]] to decrease biofouling in cooling water systems, but is later reduced to [[chloride]] to minimize the toxicity of blowdown or OTC water returned to natural aquatic environments. Hypochlorite is increasingly destructive to wooden cooling towers as pH increases. Chlorinated phenols have been used as biocides or leached from preserved wood in cooling towers. Both hypochlorite and [[pentachlorophenol]] have reduced effectiveness at pH values greater than 8.{{sfn|Betz|pages=203–209}} Non-oxidizing biocides may be more difficult to detoxify prior to release of blowdown or OTC water to natural aquatic environments.<ref>{{cite web |url=https://www.evs.anl.gov/publications/doc/ANL-Biocide_Usage.pdf |title=Biocide Usage in Cooling Towers in the Electric Power and Petroleum Refining Industries |last1=Veil |first1=John A. |last2=Rice |first2=James K. |last3=Raivel |first3=Mary E.S. |website= |publisher=United States Department of Energy |accessdate=23 June 2021 }}</ref>

Concentrations of [[polyphosphate]]s or [[phosphonate]]s with zinc and chromates or similar compounds have been maintained in cooling systems to keep heat exchange surfaces clean soenough that a film of [[Iron(III) oxide#Gamma phase|gamma iron oxide]] and [[zinc phosphate]] maycan inhibit corrosion by passivating anodic and cathodic reaction points.{{sfn|Betz|pages=198–199}} These increase salinity and total dissolved solids, and [[phosphorus]] compounds may provide the limiting essential nutrient for algal growth contributing to biofouling of the cooling system or to eutrophication of natural aquatic environments receiving blowdown or OTC water. Chromates reduce biofouling in addition to effective corrosion inhibition in the cooling water system, but residual toxicity in blowdown or OTC water has encouraged reducedlower chromate concentrations and the use of less -flexible corrosion inhibitors.{{sfnp|Kemmer|1979|pages=38-20, 38-21}} Blowdown may also contain [[chromium]] leached from cooling towers constructed of wood preserved with [[chromated copper arsenate]].<ref>{{cite web |url=http://npic.orst.edu/ingred/ptype/treatwood/ccaleach.html |title=Leaching of CCA From Treated Wood |last= |first= |website= |publisher=National Pesticide Information Center |accessdate=23 June 2021 }}</ref>

[[Total dissolved solids]] or TDS (sometimes called filtrablefilterable residue) is measuredreported as the mass of residue remaining when a measured volume of [[filter (chemistry)|filtered]] water is [[evaporate]]d.{{sfnp|Franson|1975|pp= 89-98 }} [[Salinity]] measuresindicates water [[density]] or [[conductivity (electrolytic)|conductivity]] changes caused by dissolved materials.{{sfnp|Franson|1975|pp= 99-100 }} Probability of scale formation increases with increasing total dissolved solids. Solids commonly associated with scale formation are [[calcium]] and [[magnesium]] both as [[carbonate]] and [[sulfate]]. Corrosion rates initially increase with salinity in response to increasing electrical conductivity, but then decrease after reaching a peak as higher levels of salinity decrease dissolved oxygen levels.{{sfn|Betz|pages=183–184}}

Some groundwater contains very little oxygen when pumped from wells, but most natural water supplies include dissolved oxygen. Increasing Corrosionoxygen increasesconcentrations withaccelerate increasing oxygen concentrationscorrosion.{{sfn|Betz|pages=183–184}} Dissolved oxygen approaches saturation levels in cooling towers. Dissolved oxygenIt is desirablebeneficial in blowdown or OTC water being returned to natural aquatic environments.<ref>{{cite web |url=http://www.state.ky.us/nrepc/water/ramp/rmdo2.htm |title=Dissolved Oxygen and water quality |last= |first= |website= |publisher=State of Kentucky |accessdate=23 June 2021 }}</ref>

Water ionizes into [[hydronium]] (H₃O⁺) [[cation]]s and [[hydroxide]] (OH⁻) [[anion]]s. The concentration of ionized [[hydrogen]] (as protonated water) in a cooling water system is expressedreported as the [[pH]] level.{{sfnp|Franson|1975|pp= 406-407 }} Low pH values increase the rate of corrosion while; high pH values encourage scale formation. [[Amphoterism]] is uncommon among metals used in water cooling systems, but [[aluminum]] corrosion rates increase with pH values above 9. [[Galvanic corrosion]] may be severe in water systems with [[copper]] and aluminum components. [[Acid]] maycan be added to cooling water systems to prevent scale formation if the pH decrease will offset increased salinity and dissolved solids.{{sfn|Betz|pages=191–194}}

Few other cooling applications approach the large volumes of water required to condense low -pressure steam at [[power station]]s.<ref>{{Cite report

|publisherlocation= Washington, D.C.

}} Document No. EPA/310-R-97-007. p. 79.</ref> Many facilities, particularly electric power plants, use millions of gallons of water per day for cooling.<ref>EPA (2010). [http://www2.epa.gov/sites/production/files/2015-04/documents/partial-list-of-facilities-subject-to-cwa-316b_2010.pdf "Partial List of Facilities Subject to Clean Water Act 316(b)."]</ref> Water cooling on this scale may alter natural water environments and create new environments. [[Thermal pollution]] of rivers, estuaries and coastal waters is a consideration when siting such plants. Water returned to aquatic environments at temperatures higher than the ambient receiving water modifymodifies aquatic habitat by increasing biochemical reaction rates and decreasing the oxygen saturation capacity of the habitat. Temperature increases initially favor a population shift from species requiring the high-oxygen concentration of cold water to those enjoying the advantages of increased metabolic rates in warm water.{{sfnp|Reid|1961|pages=267–268}}

'''Once-through cooling''' (OTC) systems may be used on very large rivers or at [[coastal]] and [[estuarine]] sites. These power stations put the [[waste heat]] into the river or coastal water. These OTC systems thus rely upon aan goodample supply of river water or seawater for their cooling needs. Such facilities are built with intake structures designed tofor pumpbringing in large volumes of water at a high rate of flow. These structures tend to also pull in large numbers of fish and other aquatic organisms, which are killed or injured on the [[fish screen|intake screens]].<ref name="EPA-intakes" >EPA (2014). [http://www2.epa.gov/cooling-water-intakes "Cooling Water Intakes."]</ref> Large flow rates may immobilizetrap slow-swimming organisms including [[fish]] and [[shrimp]] on [[fish screen|screens]] protecting the small bore tubes of the heat exchangers from blockage. High temperatures or pump turbulence and shear may kill or disable smaller organisms passingthat pass through the screens entrained with the cooling water.<ref>{{cite report |title=Economic and Benefits Analysis for the Final Section 316(b) Phase II Existing Facilities Rule |url=http://www2.epa.gov/sites/production/files/2015-04/documents/cooling-water_phase-2_economics_2004.pdf |date=2004 |publisher=EPA |id=EPA 821-R-04-005}}</ref>{{rp|Ch. A2}} OverMore than 1,200 power plants and manufacturersmanufacturing use OTC systemsfacilities in the U.S. use OTC systems;<ref name="EPA-TDD-existing">{{cite report |title=Technical Development Document for the Final Section 316(b) Existing Facilities Rule |url=http://www.epa.gov/sites/production/files/2015-04/documents/cooling-water_phase-4_tdd_2014.pdf |date=May 2014 |publisher=EPA |id=EPA 821-R-14-002}}</ref>{{rp|4-4}} and the intake structures kill billions of fish and other organisms each year.<ref>{{cite report |title=Final Regulations to Establish Requirements for Cooling Water Intake Structures at Existing Facilities; Fact sheet |url=http://www2.epa.gov/sites/production/files/2015-04/documents/final-regulations-cooling-water-intake-structures-at-existing-facilities_fact-sheet_may-2014.pdf |date=May 2014 |publisher=EPA |id= EPA 821-F-14-001 |access-date=23 November 2015 |archive-date=19 June 2020 |archive-url=https://web.archive.org/web/20200619180853/https://www.epa.gov/sites/production/files/2015-04/documents/final-regulations-cooling-water-intake-structures-at-existing-facilities_fact-sheet_may-2014.pdf |url-status=dead }}</ref> More -agile aquatic [[predator]]s consume organisms impinged on the screens; and warm water predators and [[scavenger]]s colonize the cooling water discharge to feed on entrained organisms.

The U.S. [[Clean Water Act]] requiresrequired the [[Environmental Protection Agency]] (EPA) to issue [[regulation]]s on industrial cooling water intake structures.<ref>United States. Clean Water Act, Section 316(b), {{USC|33|1316}}.</ref> EPA issued final regulations for new facilities in 2001 (amended 2003),<ref name="EPA-intakes" /><ref>EPA. ''Cooling Water Intake Structures.'' Final rule: 2001-12-18, {{USFR|66|65255}}. Amended: 2003-06-19, {{USFR|68|36749}}.</ref> and for existing facilities in 2014.<ref>EPA. [http://www.gpo.gov/fdsys/pkg/FR-2014-08-15/pdf/2014-12164.pdf "National Pollutant Discharge Elimination System—Final Regulations To Establish Requirements for Cooling Water Intake Structures at Existing Facilities and Amend Requirements at Phase I Facilities"] Final rule. ''Federal Register,'' {{usfr|79|48300}}. 2014-08-15.</ref>

As an alternative to OTC, industrial cooling towers may use recirculated river water, coastal water ([[seawater]]), or well water. Large mechanical induced-draft or forced-draft cooling towers in industrial plants continuously circulate cooling water through heat exchangers and other equipment where the water absorbs heat. That heat is then rejected <!-- engineering term, although ejected makes more sense in regular English-->to the atmosphere by the partial evaporation of some of the water in cooling towers where upflowing air is contacted withcontacts the circulating downflow ofdownflowing water. The loss of evaporated water into the air exhausted to the atmosphere is replaced by "make-up" fresh river water or fresh cooling water;, but volumesthe amount of water lost during evaporative cooling may decreaseaffect the natural habitat for aquatic organisms. SinceBecause the evaporation ofevaporated pure water is replaced by make-up water containing carbonates and other dissolved salts, a portion of the circulating water is also continuously discarded as "blowdown" water to preventminimize the excessive build-up of salts in the circulating water; and these blowdown wastes may change the receiving water quality.<ref>{{cite book |last=Beychok |first=Milton R. |title=Aqueous Wastes from Petroleum and Petrochemical Plants |edition=1st |publisher=John Wiley and Sons |year=1967 |LCCNlccn=67019834 |title-link=Aqueous Wastes from Petroleum and Petrochemical Plants}} (See Chapter 2 for material balance relationships in a cooling tower)</ref>

{{detailsfurther|Internal combustion engine cooling}}

The heated coolant mixture can be used to warm the air inside the car by means of the [[heater core]]. Also, the [[water jacket]] around an engine is very effective at deadening mechanical noises, which makesmaking the engine quieter.

{{DetailsFurther|Hopper cooling}}

An open water cooling system makes use of [[evaporative cooling]], lowering the temperature of the remaining (unevaporated) water. This method was common in early internal combustion engines, until scale buildup was observed from dissolved salts and minerals in the water. Modern open cooling systems continuously waste a fraction of recirculating water as blowdown to remove dissolved solids at concentrations low enough to prevent scale formation. Some open systems use inexpensive [[tap water]], but this requires higher blowdown rates than [[purified water|deionized]] or [[distilled water]]. Purified water systems still require blowdown to remove the accumulation of byproducts of chemical treatment to prevent corrosion and biofouling.{{sfn|Betz|page=192}}

Water coolingfor alsocooling has a [[boiling point]] temperature of around 100 degrees C at atmospheric pressure. Engines operating at higher temperatures may require a pressurized recycle loop to prevent overheating.<ref name="Sturgess">{{cite web|last=Sturgess |first=Steve |url= http://www.truckinginfo.com/channel/maintenance/article/story/2009/08/column-keep-your-cool.aspx |title= Column: Keep Your Cool |publisher= Heavy Duty Trucking|date= August 2009 |access-date=April 2, 2018}}</ref> Modern automotive cooling systems often operate at {{Convert|15|psi|kPa|0|abbr=on}} to raise the boiling-point of the recycling water coolant and reduce evaporative losses.<ref name=HowStuffWorks>{{cite web

The use of water cooling carries the risk of damage from freezing. Automotive and many other engine cooling applications require the use of a water and [[antifreeze]] mixture to lower the freezing point to a temperature unlikely to be experienced. Antifreeze also inhibits corrosion from dissimilar metals and can increase the boiling point, allowing a wider range of water cooling temperatures.<ref name="HowStuffWorks"/> Its distinctive odor also alerts operators to cooling system leaks and problems that would go unnoticed in a water-only cooling system. The heated coolant mixture can also be used to warm the air inside the car by means of the [[heater core]].

Since approximately 1930 it is common to use water cooling for tubes of powerful transmitters. As these devices usesuse high operation voltages (around 10 kV), the use of deionized water is required and it has to be carefully controlled.

Modern solid-state transmitters can be built so that even high -power transmitters do not require water cooling. Water cooling is however also sometimes used for thyristors of HVDC valves, for which also the use of deionized water is required.{{Citation needed

Liquid cooling techniques are increasingly being used for the thermal management of electronic components. This type of cooling is a solution to ensure the optimisation of energy efficiency while simultaneously minimising noise and space requirements. Especially useful in supercomputers or Data Centers asbecause maintenance of the racks is quick and easy. After disassembly of the rack, advanced -technology quick -release couplings eliminate spillage for the safety of operators and protectsprotect the integrity of fluids (no impurities in the circuits). These couplings are also capable of being locked (Panel mounted?) to allow blind connection in difficult -to -access areas.{{Citation needed

{{Redirect|T-Line|the rail line in San Francisco|T Third Street|the rail line in Tacoma|Line T Line (Sound Transit)|the planned transit line in Hamilton, Ontario|BLAST network|a shorthand system|Teeline Shorthand}}

[[File:CFD Water Cooled Copper Cold Plate.gif|thumb|This 60mm60 mm diameter by 10mm10&nbsp;mm high impingement-type water-cooled copper cold plate (heat sink) animation shows temperature contoured flow trajectories, predicted using a [[Computational fluid dynamics|CFD]] analysis package.]]

Water cooling often adds complexity and cost in comparison to air cooling design by requiring a pump, tubing or piping to transport the water, and a radiator, often with fans, to reject the heat to the atmosphere. Depending on the application, water cooling may create an additional element of risk where leakage from the water coolant recycle loop maycan corrode or short-circuit sensitive electronic components.

The primary advantage of water cooling for cooling [[Central processing unit|CPU]] cores in computing equipment is transporting heat away from the source to a secondary cooling surface to allow for large, more optimally designed [[radiator]]s rather than small, relatively inefficient fins mounted directly on the heat source. Cooling hot computer components with various fluids has been in use since at least the [[Cray-2]] in 1982, usingwhich used [[Fluorinert]]. Through the 1990s, water cooling for home PCs slowly gained recognition among enthusiasts, but it started to becomebecame noticeably more prevalent after the introduction of the first Gigahertz-clocked processors in the early 2000s. As of 2018, there are dozens of manufacturers of water cooling components and kits, and many computer manufacturers include preinstalled water cooling solutions for their high-performance systems.

Water cooling can be used to coolfor many computer components, but usually it is used for the [[CPU cooling|CPU]] and [[Graphics processing unit|GPUs]]. Water cooling usuallytypically uses a [[water block]], a [[pump|water pump]], and a water-to-air heat exchanger. By transferring device heat to a separate larger heat exchanger which can variously be made large and useusing larger, lower-speed fans, water cooling can allow quieter operation, improved processor speeds ([[overclocking]]), or a balance of both. Less commonly, [[Northbridge (computing)|Northbridges]], [[Southbridge (computing)|Southbridges]], [[Hard disk|hard disk drives]], [[Random access memory|memory]], [[voltage regulator module]]s (VRMs), and even [[Power supply|power supplies]] can be water-cooled.<ref>{{cite web|url=http://koolance.com/1300-1700w-liquid-cooled-power-supply |title=Koolance 1300/1700W Liquid-Cooled Power Supply |publisher=Koolance.com |date=2008-03-22 |access-date=2018-01-19}}</ref>

Internal radiator size may vary: from 40mm40&nbsp;mm dual fan (80mm80&nbsp;mm) to 140 quad fan (560mm560&nbsp;mm) and thickness from 30mm30&nbsp;mm to 80mm80&nbsp;mm. Radiator fans may be mounted on one or both sides. External radiators can be much larger than their internal counterparts as they do not need to fit in the confines of a computer case. High -end cases may have two rubber grommeted ports in the back for the inlet and outlet hoses, which allowsallow external radiators to be placed far away from the PC.

[[File:PC watercooling T-Line-2009-12-03.jpg|right|thumb|200px|Typical 2000s single-[[waterblock]] DIY [[Watercooling]]watercooling setup in a PC utilizing a T-Line]]

A ''T-Line'' is used to remove trapped air bubbles from the circulating water. It is made with a t-connector and a capped-off length of tubing. The tube n acts as a mini-reservoir and allows air- bubbles to travel into it as they are caught into the "tee" connector, and ultimately travelremoved out offrom the system (by bleeding). The capped line may be capped with a fill-port fitting to allow the release of trapped gas and the addition of liquid. {{citation needed|date=January 2020}}

Water coolers for desktop computers were, until the end of the 1990s, homemade. They were made from car [[radiator (engine cooling)|radiators]] (or more commonly, a car's [[heater core]]), [[aquarium]] pumps and home-made water blocks, laboratory-grade PVC and silicone tubing and various reservoirs (homemade using plastic bottles, or constructed using cylindrical acrylic or sheets of acrylic, usually clear) and or a [[T-Line]]. More recently{{when|date=May 2022}} a growing number of companies are manufacturing water-cooling components compact enough to fit inside a computer case.<ref>{{Cite web |date=2022-05-06 |title=Featured Projects – LiquidHaus |url=https://www.liquidhaus.com/pages/gallery |access-date=2022-05-06 |website= |archive-url=https://web.archive.org/web/20220506071434/https://www.liquidhaus.com/pages/gallery |archive-date=6 May 2022 |url-status=dead}}</ref> This, and the trend to CPUs of higher power dissipation, has greatly increased the popularity of water cooling.

Dedicated overclockers have occasionally used [[vapor-compression refrigeration]] or [[Peltier-Seebeck effect|thermoelectric coolers]] in place of more common standard heat exchangers. Water cooling systems in which water is cooled directly by the evaporator coil of a phase change system are able to chill the circulating coolant below the ambient air temperature (impossible with a standard heat exchanger) and, as a result, generally provide superior cooling of the computer's heat-generating components. The downside of phase-change or thermoelectric cooling is that it uses much more electricity, and [[Antifreeze (coolant)|antifreeze]] must be added due to the low temperature. Additionally, insulation, usually in the form of lagging around water pipes and neoprene pads around the components to be cooled, must be used in order to prevent damage caused by [[condensation]] of water vapour from the air on chilled surfaces. Common places from which to borrowobtain the required [[phase transition]] systems are a household [[dehumidifier]] or [[air conditioner]].<ref>{{cite web|url=https://forums.extremeoverclocking.com/showthread.php?t=354585 |title=Dehumidifier & Air Conditioner |publisher=extremeoverclocking.com |date=2011-04-05 |access-date=2018-03-11}}</ref>

An alternative cooling systemscheme, which also enables components to be cooled below the ambient temperature, butwhile which obviatesobviating the requirement for antifreeze and lagged pipes, is to place a [[Thermoelectric cooling|thermoelectric device]] (commonly referred to as a 'Peltier junction' or 'pelt' after [[Jean Charles Athanase Peltier|Jean Peltier]], who documented the effect) between the heat-generating component and the water block. Because the only sub-ambient temperature zone now is at the interface with the heat-generating component itself, insulation is required only in that localized area. The disadvantage of such a system is a higher power dissipation.{{Citation needed|date=February 2011}}

Asus are the first and only mainstream brand to have put water -cooled laptops into mass production. Those laptops have a built -in air/water hybrid cooling system and can be docked to an external liquid cooling radiator for additional cooling and electrical power.<ref>{{Cite web|last=hermesauto|date=2016-08-16|title=The Asus ROG GX800 is a water-cooled gaming laptop with two graphics chips|url=https://www.straitstimes.com/tech/pcs/the-asus-rog-gx800-is-a-water-cooled-gaming-laptop-with-two-graphics-chips|access-date=2021-05-07|website=The Straits Times|language=en}}</ref><ref>{{Cite web|title=Asus ROG GX800VH Watercooled Laptop Review {{!}} KitGuru|url=https://www.kitguru.net/lifestyle/mobile/laptops/leo-waldock/asus-rog-gx800vh-watercooled-laptop-review/|access-date=2021-05-07|language=en-US}}</ref>

Water is an ideal cooling medium for vessels as they are constantly surrounded by water that generally remains at a low temperature throughout the year. Systems operating with sea waterseawater need to be manufactured from [[cupronickel]], [[bronze]], [[titanium]] or similarly corrosion-resistant materials. Water containing sediment may require velocity restrictions through piping to avoid erosion at high velocity or blockage by settling at low velocity.<ref>Thermex [http://thermex.co.uk/news/blog/160-what-is-a-heat-exchanger "Heat Exchanger FAQ Page"] 2016-12-12.</ref>

[[Machine gun]]s used in fixed defensive positions sometimes use water cooling to extend barrel life through periods of rapid fire, but the weight of the water and pumping system significantly reduces the portability of water-cooled firearms. Water-cooled machine guns were extensively used by both sides during [[World War I]],; however, by the end of the war lighter weapons whichthat rivalledrivaled the firepower, effectiveness and reliability of water-cooled models began to appear on the battlefield,. thusThus water-cooled weapons have played a far lesser role in subsequent conflicts.

A [[hospital]] in [[Sweden]] relies on snow-cooling from [[Meltwater|melt-water]] from to cool its data centers, medical equipment, and maintain a comfortable ambient temperature.<ref>{{cite web|url=https://www.lvn.se/v1/In-english1/In-english/Environment-and-energy/Energy-Factor-2/Snow-cooling-in-Sundsvall/|title=Snow cooling in Sundsvall|website=www.lvn.se|language=sv|access-date=2017-08-20}}</ref>

Some nuclear reactors use [[heavy water]] as coolingcoolant. Heavy water is employed in [[nuclear reactor]]s because it is a weaker [[neutron absorber]]. This allows for the use of less -enriched fuel. For the main cooling system, normal water is preferably employed through the use of a heat exchanger, as heavy water is much more expensive. Reactors that use other materials for moderation (graphite) [[RBMK|may also use normal water for cooling]].

High-grade industrial water (produced by [[reverse osmosis]] or [[distillation]]) and potable water are sometimes used in industrial plants requiring high-purity cooling water. Production of these high -purity waters creates waste byproduct [[brine]]s containing the concentrated impurities from the source water.

In 2018, researchers from the [[University of Colorado Boulder]] and [[University of Wyoming]] invented a radiative cooling [[metamaterial]] known as "RadiCold", beingwhich has been developed since 2017. This metamaterial aids in cooling of water and increasing the efficiency of power generation, in which it would cool the underneath objects, by reflecting away the sun's rays while at the same time allowing the surface to discharge its heat as an infrared thermal radiation.<ref>{{cite journal |author1=Dongliang Zhao |author2=Ablimit Aili|author3=Yao Zhai |author4=Jiatao Lu |author5=Dillon Kidd |author6=Gang Tan |author7=Xiaobo Yin |author8=Ronggui Yang |title=Subambient Cooling of Water: Toward Real-World Applications of Daytime Radiative Cooling |journal=Joule|volume=3|pages=111–123|date=26 October 2018 |doi=10.1016/j.joule.2018.10.006 |doi-access=free }}</ref>

|lastlast1=Goldman

|firstfirst1=Charles R.

* {{Cite book |last=King, |first=James J. ''|title=The Environmental Dictionary'' (|edition=3rd Edition). |publisher=John Wiley & Sons (|year=1995). {{|ISBN|=0-471-11995-4}}

* {{Cite book |last=Reid, |first=George K. ''|title=Ecology in Inland Waters and Estuaries.'' |publisher=Van Nostrand Reinhold (|year=1961).}}