1. What is the Air Flow Formula?

The air flow formula calculates volumetric airflow rate from cross-sectional area and velocity. It is fundamental in HVAC, ventilation design, and fluid dynamics applications.

2. How Does the Calculator Work?

The calculator uses the air flow formula:

Where:

• \( Q \) — Volumetric airflow rate (m³/s or CFM)
• \( A \) — Cross-sectional area (m² or ft²)
• \( v \) — Velocity (m/s or ft/min)

Explanation: The formula calculates the volume of air passing through a given cross-section per unit time based on the air velocity.

3. Importance of Airflow Calculation

Details: Accurate airflow calculation is crucial for designing ventilation systems, determining HVAC requirements, ensuring proper air exchange rates, and maintaining indoor air quality.

4. Using the Calculator

Tips: Enter cross-sectional area in square meters, velocity in meters per second, and select desired output unit. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is the difference between m³/s and CFM?
A: m³/s (cubic meters per second) is the SI unit, while CFM (cubic feet per minute) is the imperial unit. 1 m³/s = 2118.88 CFM.

Q2: How do I measure cross-sectional area?
A: For rectangular ducts: width × height. For circular ducts: π × (diameter/2)². Ensure consistent units throughout calculation.

Q3: What is typical air velocity in ventilation systems?
A: Typically 2-5 m/s (400-1000 ft/min) for main ducts, 1-3 m/s (200-600 ft/min) for branch ducts, depending on application and noise considerations.

Q4: Can this formula be used for liquids?
A: Yes, the same principle applies to any incompressible fluid flow, though units and conversion factors may differ.

Q5: What factors affect airflow accuracy?
A: Duct shape, surface roughness, temperature, pressure, and measurement instrument accuracy can all affect real-world airflow calculations.