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Load & Sizing โœ“ ISO/ASHRAE Thermodynamic Math โ€ข Calibrated for 42ยฐC Tropical Ambient

Duct Sizer & Friction Rate Calculator

Size HVAC supply and return ducts accurately using the equal friction method. Get round diameters and equivalent rectangular duct sizes.

โšก Live Interactive Computation Engine โœ“ Real-Time Field Calibrated
Sized Duct Dimensions
12" Round (ร˜)
Equivalent: 14" ร— 10" Rectangular
Velocity: 1,020 FPM (Low Noise)
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Governing Formula:
Equivalent Diameter D = 0.55 ร— (CFM^0.38 / Friction^0.13); Rectangular Dimension = 1.25 ร— D ร— Height
Pune Field Notes & Environmental Standards:

Based on equal friction method (standard 0.08 to 0.10 in. WC per 100 ft of duct run).

Technical Engineering Guide & Field Diagnostic Practices

Proper duct sizing ensures uniform airflow across all diffuser grills while minimizing fan motor static pressure and duct acoustic turbulence. An oversized duct costs more and reduces throw distance; an undersized duct causes high air whistling and excessive fan electrical consumption.

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