Convert Millimeters of Water to Barye

Convert Millimeters of Water (mmH₂O) to Barye (Ba) instantly and accurately.

Millimeters of Water (mmH₂O)
Barye (Ba)

Conversion Formula

Ba = mmH₂O × 98.0665

About Millimeters of Water

One millimetre of water column (mmH₂O) = pressure from 1 mm of fresh water at standard gravity = exactly 9.80665 Pa. Preferred for very low differential pressures in HVAC: ductwork static pressures, fan curves, filter resistance, and building pressurisation are in mm WC. Gas valve operating pressures are typically 0.5-3 mm WC; clean-room cascade differentials 12-25 mm WC. A domestic gas hob manifold operates at ~20 mm WC on natural gas. Also used in spirometer calibration and hospital oxygen delivery systems. 1 mmH₂O = 9.80665 Pa.

About Barye

The barye (Ba) is the CGS unit of pressure - 1 dyne/cm² = exactly 0.1 Pa = 1 µbar. Standard atmosphere = 1,013,250 Ba. It dominated physics and laboratory science from the mid-19th century until SI adoption. Legacy acoustic CGS literature used 1 barye (0.1 Pa) as the underwater reference pressure, creating a 100 dB offset versus the modern 1 µPa reference - a critical correction when comparing historical and modern underwater acoustics databases. Still encountered in classical fluid mechanics derivations and early 20th-century meteorological literature. 1 Ba = 0.1 Pa.

Quick Reference Table

Millimeters of Water (mmH₂O)Barye (Ba)
1 mmH₂O98.0665 Ba
2 mmH₂O196.133 Ba
5 mmH₂O490.332 Ba
10 mmH₂O980.665 Ba
25 mmH₂O2451.66 Ba
50 mmH₂O4903.32 Ba
100 mmH₂O9806.65 Ba

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