Water cooling
Water coolers utilising convective heat transfer are used inside high-end personal computers to lower the temperature of CPUs and other components.
[4] Preservation of machinery in the presence of hot water has been improved by addition of corrosion inhibitors including zinc, chromates and phosphates.
[8] Residual concentrations of biocides and corrosion inhibitors are of potential concern for OTC and blowdown from open recirculating cooling water systems.
Flow characteristics of recirculating cooling water systems encourage colonization by sessile organisms using the circulating supply of food, oxygen and nutrients.
[14] Non-oxidizing biocides may be more difficult to detoxify prior to release of blowdown or OTC water to natural aquatic environments.
[16] 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.
[7] Blowdown may also contain chromium leached from cooling towers constructed of wood preserved with chromated copper arsenate.
Amphoterism is uncommon among metals used in water cooling systems, but aluminum corrosion rates increase with pH values above 9.
Acid can be added to cooling water systems to prevent scale formation if the pH decrease will offset increased salinity and dissolved solids.
[22] Few other cooling applications approach the large volumes of water required to condense low-pressure steam at power stations.
[26] Large flow rates may trap slow-swimming organisms including fish and shrimp on 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 that pass through the screens entrained with the cooling water.[27]: Ch.
A2 More than 1,200 power plants and manufacturing facilities in the U.S. use OTC systems;[28]: 4–4 the intake structures kill billions of fish and other organisms each year.
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.
Purified water systems still require blowdown to remove the accumulation of byproducts of chemical treatment to prevent corrosion and biofouling.
[35] Modern automotive cooling systems often operate at 15 psi (103 kPa) to raise the boiling-point of the recycling water coolant and reduce evaporative losses.
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.
This type of cooling is a solution to ensure the optimisation of energy efficiency while simultaneously minimising noise and space requirements.
After disassembly of the rack, advanced-technology quick-release couplings eliminate spillage for the safety of operators and protect the integrity of fluids (no impurities in the circuits).
Through the 1990s, water cooling for home PCs slowly gained recognition among enthusiasts, but it became noticeably more prevalent after the introduction of the first Gigahertz-clocked processors in the early 2000s.
Less commonly, Northbridges, Southbridges, hard disk drives, memory, voltage regulator modules (VRMs), and even power supplies can be water-cooled.
High-end cases may have two rubber grommeted ports in the back for the inlet and outlet hoses, which allow external radiators to be placed far away from the PC.
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 removed from the system by bleeding.
Dedicated overclockers have occasionally used vapor-compression refrigeration or thermoelectric coolers in place of more common standard heat exchangers.
[citation needed] To avoid damage from condensation around the Peltier junction, a proper installation requires it to be "potted" with silicone epoxy.
[citation needed] Apple's Power Mac G5 was the first mainstream desktop computer to have water cooling as standard (although only on its fastest models).
[43] Plant transpiration and animal perspiration use evaporative cooling to prevent high temperatures from causing unsustainable metabolic rates.
A hospital in Sweden relies on snow-cooling from melt-water to cool its data centers, medical equipment, and maintain a comfortable ambient temperature.
