Using water as refrigerant requires to work at operating condition close to its triple point. At these low pressures, knowledge on heat transfer phenomena is insufficient.

Thus, the aim of this study is to observe the impact of the channel thickness on the performance of a smooth plate-type evaporator in conditions that occurs in chillers using water as refrigerant.

After an introduction of the experimental set-up used, performances obtained with a channel thickness of 2 mm, 4 mm and 6 mm are shown. Comparison in term of overall heat transfer coefficient and flow boiling is done for these three thicknesses.

It is shown that although the performances may slightly increase with the increase of the channel thickness, for some operating conditions the trend is reversed. In all the experimental domain covered, the highest cooling capacity is obtained for a thickness of the channel of 2 mm. However, for this point, liquid is evacuated off the evaporator by the vapor flow.