VALICALC · TECHNICAL REFERENCE

Duct Velocity Reference

Compare authored duct velocity scenarios at your airflow, view the required area and round diameter, then use the chosen velocity in Duct Size.

SCENARIO MATRIX

Search within the verified subset. Numeric sizes match complete designations; a nearby size is a candidate, not an exact match.

SELECTED REFERENCE

3 m/s scenario

Mean velocity
3 m/s
Required area
33,333.333 mm²
Equal-area round diameter
206.013 mm
All fields & cell provenance

v1.2.0 · verified 2026-10-06 · values use the valid conditions shown above

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3 m/s scenario3 m/sBack to answer ↑

Explore the verified data

7 matching rows · 7 in this subset

Duct Velocity Reference, metric display
Velocity scenarioMean velocityRequired areaEqual-area round diameterActions
1 m/s scenario1 m/s100,000 mm²356.825 mm
2 m/s scenario2 m/s50,000 mm²252.313 mm
3 m/s scenario3 m/s33,333.333 mm²206.013 mm
4 m/s scenario4 m/s25,000 mm²178.412 mm
5 m/s scenario5 m/s20,000 mm²159.577 mm
7.5 m/s scenario7.5 m/s13,333.333 mm²130.294 mm
10 m/s scenario10 m/s10,000 mm²112.838 mm

1 m/s scenario

Mean velocity
1 m/s
Required area
100,000 mm²
Equal-area round diameter
356.825 mm

2 m/s scenario

Mean velocity
2 m/s
Required area
50,000 mm²
Equal-area round diameter
252.313 mm

3 m/s scenario

Mean velocity
3 m/s
Required area
33,333.333 mm²
Equal-area round diameter
206.013 mm

4 m/s scenario

Mean velocity
4 m/s
Required area
25,000 mm²
Equal-area round diameter
178.412 mm

5 m/s scenario

Mean velocity
5 m/s
Required area
20,000 mm²
Equal-area round diameter
159.577 mm

7.5 m/s scenario

Mean velocity
7.5 m/s
Required area
13,333.333 mm²
Equal-area round diameter
130.294 mm

10 m/s scenario

Mean velocity
10 m/s
Required area
10,000 mm²
Equal-area round diameter
112.838 mm

How to use this data

For entered Q, required area A=Q/v and equal-area round diameter d=√(4A/π). Use the selected velocity as a planning input; calculate straight-duct losses in Duct Size.

    CHECK THE METHOD

    Worked example

    At 0.1 m³/s and 3 m/s, required area is 0.033333 m² and equal-area round diameter is about 206.01 mm.

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    CalculatorDuct Size Calculator

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    Common lookup questions

    Can I use these values as a universal specification?

    These are planning scenarios, not universal recommended velocity ranges. Noise, fittings, pressure loss, application and local requirements must be evaluated separately.

    TRACEABLE DATA

    Sources, scope & verification

    Dataset v1.2.0
    Last verified:

    Seven authored comparison velocities, not prescribed limits for residential, commercial, acoustic or grease-exhaust systems.

    Values are curated product facts or generated scenarios. Paid standards, complete catalogs and source diagrams are not reproduced. A verification date applies to this documented subset.

    Duct area and airflow relationship ↗

    Type A · Greenheck · Options, Accessories and Engineering, October 2021, ACC-34

    Original generated scenarios from the stated equations; source tables/text/drawings are not reproduced.

    Full provenance & artifact record
    Source checked
    2026-10-06
    Use basis
    authored-formula
    Artifact SHA-256
    No retained source artifact hash; see the stated source and verification record.