The convective heat transfer characteristics of ice slurries flowing vertically upward in a rectangular channel have been experimentally investigated. At steady state, the local heat transfer coefficients were obtained during convective melting, and the effects of ice fraction, Reynolds number and wall heat flux were determined. To gain more insights into the flow properties, local measurements of the axial mixture velocity, temperature and ice fraction distributions were also made near a heated wall. Four main factors were shown to enhance the convective heat transfer coefficient of ice slurries relative to single-phase flow: (1) the ice fraction, (2) thermally and/or hydrodynamically developing flow conditions, (3) mixed-convection and (4) non-Newtonian effects experienced at Re < 4000. Two new and simple heat transfer correlations are also proposed for the practical design of compact heat exchangers involving phase change ice slurries. (c) 2005 Elsevier Ltd. All rights reserved.