We exploit recent developments on single-particle capture laws (Rosner et al., 1992, 1994) and rational correlations for inertial impaction on a circular cylinder (Israel and Rosner, 1983; Wessel and Righi, 1988) in high Reynolds number crossflow to predict local deposition I rates on heat exchanger tubes immersed in polydispersed particle-laden streams of combustion products. Three distinct classes of single-particle capture laws are explicitly considered : constant capture fraction, s (independent of impinging particle velocity and angle of incidence); "on-off" capture behavior expected on a clean, particle-free smooth surface; and capture on a dry, sufficiently thick granular deposit. Our "universal" non-dimensional results are cast in terms of the following accessible parameters : sensitivity of capture fraction to particle incident velocity and angle, ratio of mainstream velocity to the threshold velocity for particle rebound, ratio of mainstream mean particle size to critical size required for impaction on a cylindrical target, spread of log-normal mainstream particle size distribution and the characteristic slip Reynolds number for the critical size particle (for impaction) in the mainstream. Applications of our results and their generalizations are discussed. We also predict the convective heat transfer reduction associated with local fouling layer growth on heat exchanger surfaces, as well as the sensitivity of the deposition rate to several system parameters (gas velocity U, target diameter dt,...) under the control of the designer.