The results of numerical simulation of the puffing regime of a pure thermal plume, which forms above a slightly inclined (with respect to the horizon) surface have been presented. The flow structure in the near-wall region was investigated and the fields of the velocity components were analyzed. Particular attention was paid to the analysis of the distribution of instantaneous, time- and surface-averaged values of the heat transfer coefficient α. Based on the presented results, it was concluded that there was an optimal angle of inclination of the surface maintaining the most efficient heat transfer with a developed periodic flow regime.