Abstract: A dual heating process is performed in the absence of an open flame. Heat is created by a rotating prime mover(s) driving a fluid shear heater. Heat is also collected from a cooling system of the prime mover, and from any exhaust heat generated by the prime mover. The heat energy collected from all of these sources is transmitted through heat exchangers to a fluid where heat energy is desired. The fluid being heated may be glycol or air, depending on the type of heat desired.