Grille & Diffuser Sizing
The Grille & Diffuser Sizing tool assists in selecting appropriately sized air distribution outlets (grilles, registers, and diffusers) for HVAC systems. Proper sizing ensures comfortable air distribution without excessive noise or drafts. This calculator typically requires the design airflow (CFM) for the outlet and a target face velocity (FPM). It then calculates the required core area (free area). If an Ak factor (effective area factor, from manufacturer data) is provided, it can also estimate the nominal neck area for connection to ductwork.
Understanding Air Distribution Terms: Key terms include Face Velocity (air speed at grille face), Core Area (Ac - free area), Neck Area (An - duct connection area), Ak Factor (Ac/An), Throw (distance air projects), Drop/Rise (vertical air movement), Spread (horizontal dispersion), and Noise Criteria (NC level). Proper selection balances these for optimal comfort and performance.
This calculator provides an area estimate. Grille/diffuser selection also depends on throw distance, noise criteria (NC level), pressure drop, and appearance. Always consult manufacturer's performance data for final selection. This tool does not account for spread or drop characteristics.