One-dimensional turbulence (ODT) modeling approaches are considered for describing the heat transfer from a vertical isothermal wall. In this approach, near wall gas-phase conduction processes are treated exactly while the effect of turbulent mixing is accounted for using triplet mapping stirring events. A new buoyancy generation production term is proposed, based on the vorticity transport scaling arguments, to account for the generation of large scale eddy mixing events. Both temporal and spatial implementations of ODT are explored and compared to the experimental data of Tsuji and Nagano. Comparisons of velocity, temperature, and Nusselt number show overall excellent agreement of simulation results to experimental data and to established inner and outer scaling laws for buoyancy driven boundary layers. (c) 2006 Elsevier Ltd. All rights reserved.