Process

• An evaporator is the component of a refrigeration device in which the coolant is transformed from a high-pressure liquid to a gas (evaporates). The high-pressure coolant enters the evaporator from the expansion valve at high pressure through a small hole. The pressure of the coolant is then released inside the evaporator, causing it to turn into a gas and absorb heat from the surrounding air. The now-cooled air is usually distributed around the surrounding area by a fan. The gas then passes into the compressor to continue the cycle.
  
  

Structure

• An evaporator typically consists of tubes, in which the liquid turns into a gas, and fins, to aid in heat transfer. It is also where the fan, which distributes the cool air, is placed.
  
  

Physics

• The process by which an evaporator cools the surrounding air takes advantage of the fact that liquid molecules draw in energy in the form of heat as they expand to turn into gas. In this way, evaporating molecules effectively suck heat from the surrounding air molecules.