Particulate matter (PM) is emitted as a pollutant from many industrial processes, including coal-fired utility boilers. The control technology used to collect the majority of this PM is the ESP. A necessary tool for the ESP owner or operator is a means to understand how the unit works; when it is, or is not, functioning properly; how to identify and correct problems; and what options are available to improve its performance. The science and understanding of electrostatic precipitation has in recent years reached a high level. The physics of the electric fields, the charging of particles within the field, their migration velocity and collection, and the effect of the charged particles have become well understood. The mathematics that describes the physics has evolved. Low-cost, powerful personal computers (PCs) that are capable of finding solutions for the ESPs mathematical physics have become readily available. Software programs to perform the complicated calculations and predict the ESPs performance have been written. The ESPVI 4.0W Performance Prediction Model (ESPVI 4.0W) is an advanced and accurate ESP model capable of predicting the performance of an ESP.