Electrostatic precipitators (ESP) are widely used in industry today and much research has been carried out during the last decades Dimensional analysis (DA) allows to reduce the number of parameters necessary for defining the ESP performance and provides a reliable scaling up of the desired operating conditions from the pilot-scale to full-scale plant (based on the invariance of the pi-space) Likewise DA gives a consistent extrapolation within the range covered by dimensionless number and a greater flexibility in choice of parameters DA together with similarity analysis is presented in this work in order to obtain a functional dependence between a target number and a set of few dimensionless numbers The target selected has been the penetration i e the ratio of particle dust concentration at the outlet of the ESP (C-o) and that at the inlet of the ESP (C-1) The results can be valuable to assess the data from ESP of different operating characteristics under geometric electrical fluid dynamics and electro-hydrodynamics similarity Thus as a consequence of these analyses several quite reduced models have been formulated theoretically and later tested and validated with experimental data obtained in a pilot ESP in order to show an application of the study Four models have been fitted by linear regression resulting unsatisfactory However two additional models fitted by non-linear regression predict values of particle removal efficiency that agrees well with the experimental data Thus this paper is focused towards dimensional analysis in ESP model building showing both the reduction in effort and more effective modeling that can result (C) 2010 Elsevier B V All rights reserved