An experimental study is carried out to investigate the characteristics of the evaporation heat transfer for different fluids. Namely, pure refrigerants fluids (R22 and R134a), azeotropic and quasi-azeotropic mixtures (R404A, R410A, 8507) and zeotropic mixtures (R407C and R417A). The test section is a smooth, horizontal, stainless steel tube (6 mm ID, 6 m length) uniformly heated by the Joule effect. The flow boiling characteristics of the refrigerant fluids are evaluated in 250 different operating conditions. Thus, a data-base of more than 2000 data points is produced. The experimental tests are carried out varying: (i) the refrigerant mass fluxes within the range 200-1100 kg/m(2) s; (ii) the heat fluxes within the range 3.50-47.0 kW/m(2); (iii) the evaporating pressures within the range 3.00-12.0 bar. In this study, the effect on measured heat transfer coefficient of vapour quality, mass flux, saturation temperature, imposed heat flux, thermo-physical properties are examined in detail. (C) 2007 Elsevier Ltd. All rights reserved.