A novel model for three-dimensional (313) global simulation of heat transfer in a Czochralski (CZ) furnace for silicon crystal growth was proposed. Convective, conductive and radiative heat transfers in the furnace are solved together in a conjugated way by a finite control-volume method. A mixed 2D/3D space discretization technique was developed, and concepts of 2D domain and 3D domain for a CZ furnace were proposed. This technique enables 3D global simulations to be conducted with moderate requirements of computer memory and computation time. A 2D global simulation was carried out to obtain good initial conditions for 3D global modeling to speed up the global iteration. The model was demonstrated to be valid and reasonable. (c) 2005 Elsevier Ltd. All rights reserved.