Hmmm, my experience with both Kryotherm, as well as actual playing around, seems to suggest that the hot-cold side delta of a TEC is somewhat proportional to Vin/Vmax * dTmax, even when given near perfect insulation and thermal transfer efficiency (99.99 Rins and 0.001 for Rh and Rc).
As you lower Vin, you are also lowering the maximum delta from the hot to cold sides.
This was something that I especially learned when playing with the TEC chiller was that while 5v Vin being fed to a 226W TEC mean that the TEC still moved a LOT of heat, its heat moving power dropped away very rapidly at anything greater than an (estimated) ~15C difference between the pelt hot and cold sides.
In essence, while undervolting a TEC results in much higher efficiency, it also comes at the expense of the achievable delta between the hot and cold sides. So while running a 226W TEC at 5V on a 50W heat source can be easily managed by the TEC, expecting it to get much more than 10C below ambient is likely to result in disappointment.
|