I am using 4 TEC1-12706 thermoelectric cooler on a suitcase, by cutting 4 holes to fit these through and sealed them. All of them are connected to 12V DC supply from a SMPS and each of them have attached heatsinks with 12V DC fans on their hot sides (which is facing outside the bag).
When run temp 34.9 C, the cold sides on the inside of the bag do get cold enough. Leaving it overnight, i see cold water at the base of the suitcase, but the air itself is not much colder temp 31.2 C than it was before (the cold surfaces are still quite cold).
Assuming this is because of improper temperature flow, i attach 4 heatsinks with fans on the cold sides as well.
When run temp 32.5 C, the heatsinks on the cold side feel very slightly cold. Leaving it overnight, there is neither any water formation, nor is the temperature cold enough temp 31.2 C.
Why is this not working? What am i doing wrong heer?
This is my first experience with Peltier coolers.
Best Answer
My guess is your peltier are not enough to cool the whole suitcase (or not being applied current enough). Here is my reasoning:
1 - No heatsink on cold side + water: I guess this means when nothing is transfering heat from the suitcase to the peltier, the peltier gets cold enough to condense water.
2 - Heatsink on cold side + no water: since transfer of heat from the suitcase to the peltier is more effective now, the peltier doesnt get cold enough to condensate, hence no water is present in the morning.
So in conclusion, its either not powerful enough (by nature or lack of supply) and/or the suitcase is not well thermally insulated.
What is the current rating of your PSU? Did you wire the peltiers in series or parallel?