downstream vav layout: protect diffuser performance and access equipment connections: rtu, ahu, vav, fans & louvers vav downstream duct diffuser layout branch access noise lay out the downstream duct, branches, dampers, flex, and diffusers so the approved airflow distribution, access, ceiling coordination, and service clearances remain workable. a poor downstream layout can create noise, imbalance, inaccessible dampers, and diffuser performance complaints. approved mechanical drawings, vav submittal, tab requirements, reflected ceiling plan does this downstream vav layout preserve the approved branch arrangement, balancing access, and diffuser locations?