Heat exchanger (3; 5) comprising a gas flow path extending from a gas inlet side to an opposing gas outlet side of the heat exchanger (3, 5); and at least one heat exchange coil (8; 8a, 8b) extending through the gas flow path and being configured for allowing heat exchange between a fluid flowing through the heat exchange coil (8; 8a, 8b) and a gas flowing through the gas flow path; wherein the at least one heat exchange coil (8; 8a, 8b) comprises: a refrigerant inlet portion with an inlet terminal; a refrigerant outlet portion with an outlet terminal; and a heat exchange portion fluidly connected between the refrigerant inlet portion and the refrigerant outlet portion for allowing fluid to flow from the refrigerant inlet portion through the heat exchange portion into the refrigerant outlet portion; wherein the refrigerant inlet portion, the heat exchange portion and the refrigerant outlet portion are arranged within the gas flow path so that gas entering at the gas inlet side first passes the refrigerant outlet portion, then the refrigerant inlet portion and finally the heat exchange portion of the heat exchange coil (8; 8a, 8b) before leaving the gas flow path at the gas outlet side; and wherein the refrigerant inlet portion is provided by a single inlet tube section, the heat exchange portion is provided by at least two heat exchange tube sections (20, 22) and the refrigerant outlet portion is provided by at least two outlet tube sections (24, 26) connected in parallel, wherein the volume ratio between the volume (V in) of the refrigerant inlet portion and the sum of the volume (V ex) of heat exchange portion and the volumen (V out) of the refrigerant outlet portion is between 1:3 and 1:7, in particular between 1:4 and 1:6. a gas flow path extending from a gas inlet side to an opposing gas outlet side of the heat exchanger (3, 5); and at least one heat exchange coil (8; 8a, 8b) extending through the gas flow path and being configured for allowing heat exchange between a fluid flowing through the heat exchange coil (8; 8a, 8b) and a gas flowing through the gas flow path; wherein the at least one heat exchange coil (8; 8a, 8b) comprises: a refrigerant inlet portion with an inlet terminal; a refrigerant outlet portion with an outlet terminal; and a heat exchange portion fluidly connected between the refrigerant inlet portion and the refrigerant outlet portion for allowing fluid to flow from the refrigerant inlet portion through the heat exchange portion into the refrigerant outlet portion; wherein the refrigerant inlet portion, the heat exchange portion and the refrigerant outlet portion are arranged within the gas flow path so that gas entering at the gas inlet side first passes the refrigerant outlet portion, then the refrigerant inlet portion and finally the heat exchange portion of the heat exchange coil (8; 8a, 8b) before leaving the gas flow path at the gas outlet side; and wherein the refrigerant inlet portion is provided by a single inlet tube section, the heat exchange portion is provided by at least two heat exchange tube sections (20, 22) and the refrigerant outlet portion is provided by at least two outlet tube sections (24, 26) connected in parallel, wherein the volume ratio between the volume (V in) of the refrigerant inlet portion and the sum of the volume (V ex) of heat exchange portion and the volumen (V out) of the refrigerant outlet portion is between 1:3 and 1:7, in particular between 1:4 and 1:6. a refrigerant inlet portion with an inlet terminal; a refrigerant outlet portion with an outlet terminal; and a heat exchange portion fluidly connected between the refrigerant inlet portion and the refrigerant outlet portion for allowing fluid to flow from the refrigerant inlet portion through the heat exchange portion into the refrigerant outlet portion; wherein the refrigerant inlet portion, the heat exchange portion and the refrigerant outlet portion are arranged within the gas flow path so that gas entering at the gas inlet side first passes the refrigerant outlet portion, then the refrigerant inlet portion and finally the heat exchange portion of the heat exchange coil (8; 8a, 8b) before leaving the gas flow path at the gas outlet side; and wherein the refrigerant inlet portion is provided by a single inlet tube section, the heat exchange portion is provided by at least two heat exchange tube sections (20, 22) and the refrigerant outlet portion is provided by at least two outlet tube sections (24, 26) connected in parallel, wherein the volume ratio between the volume (V in) of the refrigerant inlet portion and the sum of the volume (V ex) of heat exchange portion and the volumen (V out) of the refrigerant outlet portion is between 1:3 and 1:7, in particular between 1:4 and 1:6.