Hey, I am making a cooling system using a peltier junction with a cold finger on one side and a heat sink on the other. For my heat sink, I am depositing the heat into the phase change of a bismuth alloy (about 70 deg C). When the current across the peltier is increased and the hot side increases to large temperatures, it starts to heat up the cold side (which is bad for my project). My concept question is: Should I install a thermistor on the hot side with a PID loop in order to keep the hot side around 70 C? My concept question is if the rate at which heat is conducted across the bismuth alloy is dependent on the temperature. In other words, if the hot plate is at 100C does that mean the heat sink will disperse the heat faster than if the hot plate is at 70C? Thanks, quick assistance is appreciated.