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- Feb 12, 2016
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Sometimes I see talks about using TECs to cool high power lasers but no one gave here any info about numbers - TEC efficiency, consumption etc. And apparenly there is no specifc thread about TECs on LPF.
So sometimes I do experiments to mesure these numbers. Just for fun but for info as well.
Last year I dismantled so called "Beverage cooler&warmer" from ali. It cooled 300g of water put inside of the can at rate of half ºC pro minute from rt to about 2-3ºC (that took 1h but at rt cooling started at rate of 1/2 degree pro min).
Knowing that 1 calorie (needed to cool 1g of water at 1ºC) = 4.2 Ws, it makes 10.5W of heat extraction while energy consumption (as was given in specs) was 12Vx3A = 36W.
So the TEC inside must have been 29% (10.5/36) efficient (if we only care about wasted energy).
After that I took the thing apart - the TEC inside was not bigger than ones purchased from ali before.
This year I saw that ali had more powerful TEC based coolers there - so called "Ice cream makers". One of them I already have dismantled earlier (was posted in NUBM31T thread) but this time it was a bigger one with 110W consumption given in description.
To have precise numbers I soldered a V/A meter into the TEC line and mesured the total consumption of the whole thing incl. motor and fan with a Watt counter. So here it consumes 115W but TEC in it only consumes 92W (4A at 23V). Once turned on it starts to chill 500g of water at a rate of 4.2ºC pro 5 min = means takes 2100 calories in 5min = takes 29.4W (32% of 92W) from water to HS.
So I found the TEC efficiency to be 32% isothermically (I mean at start when temperatures are equal from both sides. Then dismantled it and check how big the TEC inside was (70x50mm)!!!
It also had huge HS (820g of Al) and huge fan and the Al bowl fully isolated by adhesive foam - and there again were no screws and I did not try to take the bowl out this time...
So sometimes I do experiments to mesure these numbers. Just for fun but for info as well.
Last year I dismantled so called "Beverage cooler&warmer" from ali. It cooled 300g of water put inside of the can at rate of half ºC pro minute from rt to about 2-3ºC (that took 1h but at rt cooling started at rate of 1/2 degree pro min).
Knowing that 1 calorie (needed to cool 1g of water at 1ºC) = 4.2 Ws, it makes 10.5W of heat extraction while energy consumption (as was given in specs) was 12Vx3A = 36W.
So the TEC inside must have been 29% (10.5/36) efficient (if we only care about wasted energy).
After that I took the thing apart - the TEC inside was not bigger than ones purchased from ali before.
This year I saw that ali had more powerful TEC based coolers there - so called "Ice cream makers". One of them I already have dismantled earlier (was posted in NUBM31T thread) but this time it was a bigger one with 110W consumption given in description.
To have precise numbers I soldered a V/A meter into the TEC line and mesured the total consumption of the whole thing incl. motor and fan with a Watt counter. So here it consumes 115W but TEC in it only consumes 92W (4A at 23V). Once turned on it starts to chill 500g of water at a rate of 4.2ºC pro 5 min = means takes 2100 calories in 5min = takes 29.4W (32% of 92W) from water to HS.
So I found the TEC efficiency to be 32% isothermically (I mean at start when temperatures are equal from both sides. Then dismantled it and check how big the TEC inside was (70x50mm)!!!
It also had huge HS (820g of Al) and huge fan and the Al bowl fully isolated by adhesive foam - and there again were no screws and I did not try to take the bowl out this time...
