When to use: Use when commissioning or programming a VAV terminal box to set its maximum cooling and minimum airflow setpoints. The maximum is sized to the zone sensible cooling load (CFM = Q / 1.08·ΔT), while the minimum must satisfy the ASHRAE 62.1 breathing-zone ventilation requirement (Vbz = Rp·Pz + Ra·Az) plus any turndown floor. If the ventilation requirement exceeds the cooling airflow, the box is undersized. A turndown above ~70% leaves little room for the box to modulate.