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Duct Area Formula:
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Duct area calculation is essential in HVAC system design to determine the proper cross-sectional area of air ducts based on airflow requirements and velocity constraints. Proper duct sizing ensures efficient airflow and system performance.
The calculator uses the fundamental duct area formula:
Where:
Explanation: This formula calculates the required duct area to maintain desired airflow at a specific velocity, balancing system efficiency and noise levels.
Details: Correct duct sizing is crucial for optimal HVAC performance. Undersized ducts increase static pressure and noise, while oversized ducts reduce velocity and may cause poor air distribution.
Tips: Enter CFM (cubic feet per minute) and Velocity (feet per minute). Typical residential velocities range from 600-900 FPM for supply ducts and 500-700 FPM for return ducts.
Q1: What Is The Recommended Velocity For Residential Ducts?
A: Supply ducts: 600-900 FPM, Return ducts: 500-700 FPM. Lower velocities reduce noise but require larger ducts.
Q2: How Does Duct Shape Affect Area Calculation?
A: Different shapes (round, rectangular) have different area formulas, but the CFM/Velocity relationship remains the same. This calculator provides area in square inches.
Q3: What Are Typical CFM Requirements?
A: Residential systems typically require 400-2000 CFM depending on home size. Commercial systems can range from 2000-50,000+ CFM.
Q4: Why Is Duct Sizing Important For Energy Efficiency?
A: Properly sized ducts reduce fan power consumption, minimize pressure drops, and improve overall system efficiency by 15-25%.
Q5: Can This Calculator Be Used For Both Supply And Return Ducts?
A: Yes, the formula applies to both, though recommended velocities differ between supply and return applications.