Why is the heat exchanger on a fridge painted matt black?
Black absorbs heat the most efficiently of all colors. White reflects it the most. You want the exchanger to be as efficient as possible.
the reason is that black not only absorbs heat faster, it also radiates heat faster. since that's what the heat exchanger does, then black is the best color.
A refrigerator doesn't have a heat exchanger. It has an evaporator, and I have no idea why it's painted black.
Black is the best for heat radiation.
The compression coils on the back of a refrigerator receive compressed refrigerant, which is hotter than room temperature. The refrigerator has to shed this heat to work. Dull black is the most emissive of colors, which means it radiates heat most effectively. Black coils, therefore, lose heat through radiation better than any other color.
