I am experimenting with stacked Peltier cells trying to build a simple diffusion cloud chamber. I noticed that when simply stacking two peltier cells the upper side reaches a temperature (around -15 C) higher than the temperature obtained (around -25 C) if I put a small aluminium plate between the two, that is cooled down by the lower peltier and dissipates heat of the upper peltier. I was wondering whether there is any physical explanation for this (e.g. the aluminium block being larger than the lower peltier is able to dissipate better the parasitic heat produced by the upper peltier) or whether this is just a random result due to poor insulation/tightening of the system.
Some more data:
- lower peltier is a 12710 module operating @12V
- upper peltier is a 12706 module operating @5V
- lower peltier is backed by a 10mm dissipator made up of 4 heat pipes surrounded by 2 aluminum radiators cooled by 3 10 cm fans .the aluminum block is 10x10 cm and thick twice the peltier
Setup 1: dissipator-->12710->10706 @ -15 C
Setup 2: dissipator->12710->aluminum block->12706 @-25
Styrofoam insulation around the thing.
In both the setups there is no thermal load but room air at the top and the temperatures achieved vary some C from one experiment to the other but stay pretty constant (10mim) during the same experiment.
any clues? Thanks!