Thermoelectric coolers

[Munroast]

Anyone know how these work ?
https://www.ebay.co.uk/itm/TEC1-127...Heatsink-Module-12-Volt-60-Watt/263975124639?

it says
Operates from 0~15.2V DC and 0~6A

what does that mean ? if I attached it to a 5 volt supply it would work at a lower output ?

if its capable of running at 15.2v and drawing 6 amps, then would that not be 90 watts ?

 

[JohnD]

I have only a hazy understanding. It has long been known but only recently used in mass market coolers at low price.

https://en.m.wikipedia.org/wiki/Thermoelectric_effect#Peltier_effect

 

[bernardgreen]

That 60 watt rating is the maximum electrical power the device will take ( at maximum voltage ) the amount of heat transfered will be considerably less.

For heating water the 60 watts plus heat transferred will be useful in heating the water.

For cooling an item the amount of heat taken from the item to be cooled will be far less than 60 watts. How much less depends on the type and quality of the semiconductor material used. That said they are interesting devices.

Be careful when using them as even a small one can cause frost bite to a damp finger.

There are data sheets available for several more expensive Peltiers HERE if you want to compare heat transfered to power consumed.

 

[Harry Bloomfield]

if its capable of running at 15.2v and drawing 6 amps, then would that not be 90 watts ?

91.2 watts, not drastically different from 90 watts.

 

[bernardgreen]

Note that with Peltier devices the maximum heat transfer is when the difference in temperature between hot side and cold side is zero

 

[SFK]

Good intro to peltiers here:
https://www.meerstetter.ch/compendium/tec-peltier-element-design-guide

Good heatsinks are critical on the warm side, becuase if the warm side gets too warm then the solder melts and device fails.

I tend to use constant voltage, variable current drivers with temperature monitoring feedback (costing >£500) as it has variable current control for precision.
Cheaper drivers are avalible, but they tend to be relay based on/off control control.
https://www.t-uk.co.uk/product/tlk3...uVzkClD-L0VXbb8YbuGYQMqHO5Dn-KW0aAiDzEALw_wcB

The device shown is rated up to 60W using 0 to 15.2V DC and 0 to 6A.
- This means that if you drive it using 15.2V you should use 0 to 3.9A (not 6A) to max out at 60W.
- This means that if you drive it using 0 to 6A you should use 10V (not 15.2V) to max out at 60W.

Peltiers are not very efficient with around 5% of the electrical energy used to power used for cooling. When from memory a compressor based fridge is >60% (need to check this).
https://rimstar.org/science_electronics_projects/peltier_effect_module_cooling_efficiency_test.htm
SFK