1. What is a Range Hood Duct Size Calculator?

Definition: This calculator determines the required cross-sectional area of a range hood duct based on airflow rate and air velocity.

Purpose: It helps homeowners, kitchen designers, and HVAC professionals properly size ductwork for efficient ventilation.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( A \) — Duct cross-sectional area (square meters, m²)
• \( Q \) — Airflow rate (cubic meters per second, m³/s)
• \( V \) — Air velocity (meters per second, m/s)

Explanation: The airflow rate is divided by the desired velocity to determine the necessary duct size for proper ventilation.

3. Importance of Proper Duct Sizing

Details: Correct duct sizing ensures efficient air movement, reduces noise, prevents backflow, and maintains optimal range hood performance.

4. Using the Calculator

Tips: Enter the airflow rate in m³/s and desired velocity (default 2.5 m/s for residential range hoods). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What's a typical airflow rate for range hoods?
A: Residential hoods typically range from 0.2-0.5 m³/s (400-1000 CFM), while commercial hoods may require 0.5-2.5 m³/s.

Q2: What velocity should I use?
A: 2.5 m/s is standard for residential, 5-7.5 m/s for commercial. Higher velocities increase noise but allow smaller ducts.

Q3: How do I convert CFM to m³/s?
A: Multiply CFM by 0.00047194745 (1 CFM ≈ 0.000472 m³/s).

Q4: What about rectangular ducts?
A: Convert area to dimensions (e.g., 0.1 m² = 0.2m × 0.5m or 0.316m × 0.316m round duct).

Q5: Does this account for duct length and bends?
A: No, for long runs or multiple bends, consider increasing duct size by 10-20% to compensate for pressure drops.