Ventilation Tools – Calculators for Fitters

Ventilation tools

Quick calculators for fitters and designers. Works straight from your phone — no login, no app.

Built by Ventmek for fitters across Sweden

Unit converter

Airflow

l/s m³/h m³/s CFM

Pressure

Pa kPa mmH₂O inH₂O

Speed

m/s km/h ft/s mph

Airflow requirements (Swedish BBR/AFS)

Minimum airflow

— l/s

— m³/h

—

Duct sizing — Spiro / round duct

Guideline: main duct 5–8 m/s · branch 3–5 m/s · to room 2–3 m/s

Calculated diameter

— mm

Recommended standard

— mm

—

Bend & offset

For two bends of equal angle — common angles: 15°, 30°, 45°.

Length of connector

— mm

⚠️ Guideline values only. Always verify against current local building codes and project documentation.

Swedish only

Ordering rectangular ducts — without mistakes

Interactive generator for order strings (Swedish ductwork notation: RK, B90/B45, S-bend, reducers, transitions, T-piece, branches). Built-in S-bend planner. Avoid costly mistakes during fabrication. Tool is in Swedish — based on standard Swedish industry notation.

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