Abstract: An evaporator for a refrigeration system, comprising a tube provided with fins and mounted in the form of a coil, conducting a refrigerating fluid therewithin and comprising tube portions (20a) arranged parallel to each other and which are transversal to the direction of a forced airflow (F) that passes externally through the evaporator (10), from a first end region (11) of air ad to a second end region (12) of air outlet of the evaporator (10). The tube portions (20a) are arranged in the form of at l (S), having an inlet end (21) provided in the second end region (12) of the evaporator (10) and an outlet end (22) prov first end region (11) of the evaporator (10), so that the refrigerating fluid flows through the coil (S) in counterflow in relation forced airflow (F).