What is the effect of the fan motor heat on the primary air in a draw-through AHU?
The effect is to raise the temperature of the air leaving the air handler. The change can be represented on a psychrometric chart as a sensible heat increase, with the air leaving condition shifted to the right by whatever is the calculated rise in dry bulb temperature. This rise needs to be factored into the system design, as the primary air condition at the primary air plenum of the units must still be that used in the selection process.
