Convert Inches of Water to Micropascals
Convert Inches of Water (inH₂O) to Micropascals (µPa) instantly and accurately.
Conversion Formula
µPa = inH₂O × 249088910
About Inches of Water
One inch of water column (inH₂O or in WC) = pressure from 1 inch of fresh water at standard gravity ≈ 249.09 Pa. The standard unit for low-pressure measurement in US HVAC and plumbing: ductwork static pressure, fan performance, filter ratings, and gas appliance manifold pressures are all specified in inches WC. Household natural gas supply pressure is typically 7 in WC (0.25 psi). Blower door tests for building air-tightness use 50 Pa ≈ 0.2 in WC test pressure. 1 inH₂O = 249.089 Pa.
About Micropascals
A micropascal (µPa) is 10⁻⁶ Pa - the standard reference unit for sound pressure levels in acoustics. The threshold of human hearing in air is 20 µPa, which defines 0 dB SPL; underwater acoustics uses 1 µPa as its reference (0 dB re 1 µPa). Blue whale calls reach ~189 dB re 1 µPa at source. Industrial noise regulations, architectural acoustics, and loudspeaker sensitivity specifications all trace back to µPa reference levels. Solar wind pressure near Earth averages ~1-6 nPa, rising to hundreds of µPa during major solar storms. 1 µPa = 10⁻⁶ Pa.
Quick Reference Table
| Inches of Water (inH₂O) | Micropascals (µPa) |
|---|---|
| 1 inH₂O | 249089000 µPa |
| 2 inH₂O | 498178000 µPa |
| 5 inH₂O | 1.245 × 109 µPa |
| 10 inH₂O | 2.491 × 109 µPa |
| 25 inH₂O | 6.227 × 109 µPa |
| 50 inH₂O | 1.245 × 1010 µPa |
| 100 inH₂O | 2.491 × 1010 µPa |