A flow regime based condensation model is developed for refrigerants in single, smooth, horizontal tubes utilizing a generalized probabilistic two-phase flow map. Flow map time fraction information is used to provide a physically based weighting of heat transfer models developed for different flow regimes. The developed model is compared with other models in the literature, with experimentally obtained condensation data of R 134a in 8.92 turn diameter tubes, and with data found in the literature for 3.14 mm, 7.04 turn, and 9.58 turn tubes with R11, R12, R134a, R22, R410A, and R32/R125 (60/40% by weight) refrigerants and a wide range of mass fluxes and qualities. (C) 2007 Elsevier Ltd. All rights reserved.