Duct Size Calculator
Calculate the correct duct size for your HVAC system with our comprehensive calculator. Determine optimal duct dimensions based on airflow, velocity, and room requirements for efficient ventilation.
Step 1: System Specifications
Understanding Duct Sizing
Proper duct sizing is essential for efficient HVAC system operation. Oversized ducts increase costs, while undersized ducts reduce airflow and efficiency. Standard residential velocity is typically 600-900 FPM.
Step 2: Duct Parameters
About Aspect Ratio
Aspect ratio is the ratio of duct width to height. Common ratios are 1:1 (square), 2:1, 3:1, and 4:1. Higher ratios provide more width but less height, which can be useful in tight spaces.
Duct Size Results
Recommended Duct Size
Duct Type Size Comparison
| Duct Type | Dimensions | Cross-Sectional Area | Equivalent Round Diameter |
|---|
Duct Size Breakdown
Duct Sizing Formula
Cross-Sectional Area (sq ft) = Airflow (CFM) / Velocity (FPM)
To calculate duct size: Divide airflow in cubic feet per minute (CFM) by velocity in feet per minute (FPM) to get required cross-sectional area in square feet.
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