Field-tested sizing calculations, supply recommendations, and report previews in our new black-and-green interface.
Cavity returns are recorded as existing conditions only; they are not assigned a verified airflow capacity. Check local code and manufacturer requirements before recommending reuse.
Measure the grille face, not the duct opening. Estimates use gross grille area; actual free area and delivered CFM must be verified.
Residential ceiling-height choices retain your original 0.8 / 0.9 / 1.0 CFM/ft² factors. Commercial occupancy uses editable preliminary airflow factors. Existing permitted outdoor-air ventilation is retained; LAS FieldMech does not recalculate ventilation requirements.
Office 1.2–1.5 · Restaurant 1.5–2.0 · Crowded assembly 3.0. Editable field-planning estimate.
Existing return stays. LAS FieldMech assumes a 24 × 24″ T-bar grille and recommends the required duct size; any additional grille is sized only for the shortfall.
Enter a room name and square footage. The gray examples are hints, not filled-in answers.