Plumbing & electrics

[jazty]

Interestingly, I looked at a peltier unit online. Somebody had coupled a peltier cooler unit $9 with a computer fan and a heat sink. They claimed frost would appear almost instantly on the peltier device. The rated power consumption was high at 12v, 5A or 60w.

On the other hand, with one of those units, a simple cooler can be turned into a refrigerator with advantages such as custom size.

If a peltier unit was planned into the power budget, that could be the way to go.

Yeh, those thermoelectric units are neat. You can even generate a small current with them if you put one side against a heat source and cool the other side! The big downside is their efficiency. They are WAY less efficient than a typical compressor refrigeration system. Also, they can only cool the air 21°C (70°F) below ambient temperature in a best-case scenario. That won't be cold enough for meat or dairy during the hotter days of summer.
I used a portable 12v cooler/refrigerator that was driven by the thermoelectric units for drinks before. It worked best if everything was pre-cooled. You had to wait all day to cool a drink down from ambient temperature.

 

[Valkyrie_2]

I'm wondering what would happen if one unit were placed with two behind it to cool the expelled heat. Sure, energy consumption would rise horribly but you could in theory end up with 40c below ambient (72,F).

 

[jazty]

There's a nice response by Jon Custer to the question of stacking thermoelectric coolers on Stackexchange: thermodynamics - Is it more efficient to stack two Peltier modules or to set them side by side? - Physics Stack Exchange
Seems like a good real-life example.

 

[Valkyrie_2]

https://www.adafruit.com/products/1335

This looks like a perfect combination of heatsink, fan and peltier.