The Evaporator coil is used to absorb heat heat into the regrigerent during the refrigeration cycle. As heat is gained by the refrigerent, the refrigerent "Evaporates" into a gas giving this coil its name. During the air conditioning cycle it is the indoor coil, In a heat pump system it is the indoor coil in cooling mode and the outdoor coil in the heating mode. Evaporator Coils require special placement and setup for the removal of condensation.