Originally Posted by LemonSlice
Just switching the polarity is bad, the hot side can get hot enough to burn some skin off your finger, also effectively killing the TEC quick. You definitely want something that is designed to generate heat and stay alive.
Thanks for your quick reply. I was thinking that when I switched polarity I would also turn off the fan on the heatsink, allowing the cold side to get very cold. Since this is different than an application on a computer when there is an active load of heat being dumped on to the cold side, I feel that it could get very very cold. Lets say -10 C as a guess. If there is a delta T of 60 C on the peltier, wouldn't the hot side stay at ~50C max. Is this still safe?
Again, a peltier is only 25$ so I don't really mind experimenting a little, I am taking on this project more to learn about peltiers than anything else.
And if heat is still an issue, I thought of a possible fix. This is my design from bottom to top. Large heatsink with fan [off] -> peltier -> small copper passively cooled heatsink -> hotplate -> beverage
And as a cooler: Large heatsink with fan [on] -> peltier -> small copper passively cooled heatsink -> coldplate -> beverage
Feel free to call any of my ideas dumb, I have 0 experience with peltiers besides reading some stuff here