A criterion for predicting the possible advantage of adopting a suction/liquid heat exchanger in refrigerating system C. Aprea a, *, M. Ascani b , F. de Rossi c a Universita Á di Salerno, Faculty of Engineering, Fisciano (Salerno), 84084, Italy b Angelantoni Industrie s.p.a., Massa Martana (Perugia), Italy c Universita Á del Sannio, Faculty of Engineering, Benevento, Italy Received 20 May 1998 Abstract An analysis for evaluating the possible advantage of adopting a suction/liquid heat exchanger, from a thermodynamic point of view, is carried out. To this purpose, a simpli®ed criterion is prented; this is also validated for many working ¯uids such as chloro¯uorocarbon (CFC)s, hydrochloro¯uorocarbon (HCFC)s and substitutes on the basis of their thermodynamic properties available in scienti®c and commercial literature.The criterion is also presented in a graphical form and two examples, referred to as R502 and R32, are given. # 1998 Elsevier Science Ltd. All rights reserved. Keywords: Refrigerating system; Suction/liquid heat exchanger; CFCs; HCFCs; Hydro¯uorocarbon (HFC) Nomenclature C unitary plant cost of the suction/liquid heat exchanger (ECU)  c p mean constant pressure speci®c heat (kJ/kg K) COP coecient of performance h speci®c enthalpy (kJ/kg) k speci®c heat ratio L compression power (kW) nslh normal speci®c latent enthalpy (kJ/kg) Q refrigerating eect (kW) Applied Thermal Engineering 19 (1999) 329±336 1359-4311/99/$ - see front matter # 1998 Elsevier Science Ltd. All rights reserved. PII: S1359-4311(98)00070-2 PERGAMON * Author for correspondence.