Thermo electcric refrigeration... is it possible?

david desharnais

hey guys.... im a senior in the Hvac program at pathfinder tech in western Ma. today.. a post graduate came in to visit so him myself and the instructor were shooting the breeze when he said something about a completely electric mini fridge.... no refrigerant in it at all... so the instructor gave me the task of trying to find some information in it.... ive come up dry .. any of you know anything about this? or a site that could give me info on it? it would be much appreciated. thanks

brad_4

http://home.howstuffworks.com/refrigerator6.htm .....Has some basic theory....
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http://www.marlow.com/TechnicalInfo/frequently_asked_questions_faqs.htm ...Has boatloads of info....

Dave_13

Peltier Effect

This link comes to you via a genius I work with!!!! LOL!!


http://www.uni-konstanz.de/physik/Jaeckle/papers/thermopower/node3.html

DaveGateway

Commercially Available

There are many commercially available thermoelectric cooling products - here's just a couple:

www.koolatron.com
www.sscooling.com

Mark J Strawcutter

cooling vs refrigeration

There are lot's of commercial versions available at Target, Wal-Mart etc.

I think thermoelectric "cooling" is a better description than "refrigeration". The best they can do is about 40degF below ambient. Not sure if this is a limitation of the technology itself or just a limitation of how it was implemented.

Mark

scrook

Melcor Thermoelectric Coolers

Look up: www.melcor.com
Melcor (among others) make/sell thermoelectric cooling modules. They are also called Peltier effect coolers. They basicly consist of a lot of thermocouple junctions in series mounted between two thin ceramic plates, but instead of looking at the voltage resulting from a temperature difference between a hot (to be measured) and cold (known temperature) junction, as a thermocouple meter does (Sebeck (sp?)effect), the thermoelectric cooler works in reverse: you apply a voltage (causing current flow) and one side is cooled while the other side heats.

They can achieve up to perhaps 60°F temperature difference from cold to hot side, but are more eficient at lower temperature differences. Stacking several can get even larger temperture differences, but is not as efficient. Tey are sold sometimes for computer CPU coolers (for overclockers), also they are often used to cool laser diodes in telecomunications equipment and other applications, and for other electronics cooling where a regular heat sink *alone* won't work, (they need a heat sink or a cool liquid supply on hot side to carry the heat away), also little desktop refrigerators.

They also may be used as heat pump type heaters, w/ COP's greater than 1 at reasonable temperature differances, making them better (though more expensive) than resistor based heater for some applications.

Note these devices are small, a fraction of an inch square to several inches square, working a fraction of a watt to maybe a few hundrew watts of heat pumped, you'd never keep your house or a full size beer keg cool with these, but you could keep a single beer can chilled.