what size heat sink do you use with a peltier?

what size heat sink do you use with a peltier, in order to make a mini usb fridge.
70w peltier

As A. says, you can only pull a MAXIMUM of 5W from the USB, potentially only 0.5W.
iceng6 years ago
Are you planing to use a Fan ??
Different heat sink shapes have different cooling abilities.
Cooling depends on the ambient temperature of the air you hope to use.

In the arctic cooling is easy.......   in Hades cooling is hell.

The PDF of the heat sink is here described.
Look under Heat sink calculations  for many articles that teach you how to
determine how you can cool fridge.

I must tell you that if you think you can pull 70watts from a USB you are
already visiting Hades....................   A