Abstract: An air preheater system, and a method of operating the same, for use in connection with the requisite supply of heated air streams to the dispensing modules of apparatus for dispensing hot melt adhesives comprises the initial separation of the incoming ambient relatively cool air into separate air streams. The separate air streams are then individually and separately heated, and the exiting or discharged heated air streams are then recombined into a single heated air stream. In this manner, any variations in the temperature levels, density, and flow rate parameters within the individual or separate heated air streams are therefore averaged out and effectively eliminated. The single heated air stream is then conducted to a distribution manifold wherein unique structure of the distribution manifold renders uniform distribution of the separate air streams to the hot melt adhesive dispensing modules possible.