Thermoelectric cool boxes
The term ‘thermoelectric’ describes when electricity is produced as a result of two different temperatures. This is known as the Peltier effect.
The Peltier effect
The Peltier effect works when cooling or heating happens when an electric current passes between two materials.
So, in the case of electric cool boxes, this typically involves two ceramic plates with a layer of semiconductor material in between.
When the electric current passes, one side of the module becomes hot and the other side becomes cold. The side that becomes hot pushes the heat back out into the surrounding air, while the cold side absorbs heat from the inside of the cool box.
Insulation and temperature regulation
Electric cool boxes are insulated, with something like a high-density polyfoam, to help keep the cold air inside. The temperature can then be regulated by a thermostat or control panel on the box.
Some models may also have a fan to help circulate the cool air inside the box, which also helps prevent mould build-up.
Thermoelectric coolers require as little as 12V to power them, which can be sourced from something like a car battery or a portable charging pack.
This is the basic physics behind how this kind of cooler works and is normally the technology behind designs that cool exclusively (as opposed to freezing or heating too).
Compressor cool boxes
This type of electric cool box works in a similar way to a thermostatic model but instead, uses an electric compressor to keep the inside of the box cold.
Compressor cool boxes are often on the more pricey end of the market as they tend to have fancy features like digital displays, temperature setting controls, and even app connectivity so you can control them from your phone.
If you’re wanting to use your electrical cooler as a freezer as well as a portable fridge, look out for compressor designs as this is the technology that powers the freezing functionality.
It’s important to note that whatever type of electric cool box you are using, it will only work when connected to a power source.