Abstract A new model for the dispersion of passive puffs is presented (puff model). The model is based on the GILTT (Generalized Integral Laplace Transform Technique) approach, a general technique for solving the advection–diffusion equation. It is a well-known hybrid method that had solved a wide class of direct and inverse problems mainly in the area of Heat Transfer and Fluid Mechanics and the solution is given in series form. It is used a boundary layer parameterization that allows the model to be applied routinely using as input simple ground-level meteorological data. A preliminary performance evaluation is shown in the case of continuous emission from an elevated source in a variable boundary layer (with a time resolution of 10min).