Air is blown into the boilers with huge fans to support the complete combustion of the coal. At full load, 2.8 million cubic feet of air per hour per boiler are moved by this forced draft fan.

The air is preheated using the hot exhaust gases from the boiler. This greatly improves the efficiency of the system. The air is preheated from 100° Fahrenheit to approximately 600° Fahrenheit while at the same time cooling the exhaust gases from 700° Fahrenheit to 300° Fahrenheit.

An induced draft fan draws the hot gases from the boiler through ducts to the electrostatic precipitators.