Editing Computer cooling (section)

===Peltier (thermoelectric) cooling===
{{Main|Thermoelectric cooling}}
[[File:Regular Peltier cooling setup for PC.png|thumb|Regular Peltier cooling setup for PCs]]

Peltier junctions are generally only around 10–15% as efficient as the ideal [[refrigerator]] ([[Carnot cycle]]), compared with 40–60% achieved by conventional compression cycle systems (reverse [[Rankine cycle|Rankine]] systems using compression/expansion).<ref>{{Cite web|url=http://www.pnl.gov/main/publications/external/technical_reports/pnnl-19259.pdf|title=The Prospects of Alternatives to Vapor Compression Technology for Space Cooling and Food Refrigeration Applications|access-date=23 January 2013|archive-url=https://web.archive.org/web/20130306021637/http://www.pnl.gov/main/publications/external/technical_reports/PNNL-19259.pdf|archive-date=6 March 2013|url-status=live}}</ref> Due to this lower efficiency, thermoelectric cooling is generally only used in environments where the solid state nature (no [[moving parts]], low maintenance, compact size, and orientation insensitivity) outweighs pure efficiency.

Modern TECs use several stacked units each composed of dozens or hundreds of thermocouples laid out next to each other, which allows for a substantial amount of [[heat transfer]]. A combination of [[bismuth]] and [[tellurium]] is most commonly used for the thermocouples.

As active heat pumps which consume power, TECs can produce temperatures below ambient, impossible with passive heatsinks, radiator-cooled [[#Liquid cooling|liquid cooling]], and heatpipe HSFs. However, while pumping heat, a Peltier module will typically consume more electric power than the heat amount being pumped.

It is also possible to use a Peltier element together with a high pressure refrigerant (two phase cooling) to cool the CPU.<ref>Kijk magazine, 2, 2020</ref><ref>{{Cite web|url=https://www.incooling.com/technology/|title=Technology &#124; Incooling|website=www.incooling.com|access-date=5 March 2020|archive-date=17 April 2021|archive-url=https://web.archive.org/web/20210417123011/https://www.incooling.com/technology/|url-status=dead}}</ref>