HVAC Ducting of two ASU’s of similar capacities with different routing was to be studied and analyzed using CFD tools. Our primary objective was to achieve the desired velocities at the vent outlets and hence correcting the static pressure developed on the ASU’s. We first validated our CFD model with the existing ducting in the facility quite accurately. Further we provided suggestions on how we can achieve our objectives and re-analyzed the same through CFD Modelling.