What is Refrigerator

Air conditioning was developed in the early 20th century to combat moldering of industrial supplies and oppressive heat in homes.

Around the same time, refrigeration entered the mass market to tackle an arguably more pressing problem: food spoilage.

Of course, for generations people had kept their foods chilled using and insulated box containing a hunk of ice.

The refrigerators that occupy nearly all American homes today combine this simple icebox with the same technology used in air conditioning.

A refrigerant fluid is made to vaporize via a change in pressure, absorbing heat from inside the fridge, and then condense to a liquid state, releasing heat into the kitchen.

Both the fridge and the air conditioner use pressure differences to promote vaporization and condensation.

They do work to overcome a rule governing natural processes: that heat can never flow from a cooler zone (such as inside a fridge) to a hotter one.