Convert Feet of Water to Technical Atmospheres
Convert Feet of Water (ftH₂O) to Technical Atmospheres (at) instantly and accurately.
Conversion Formula
at = ftH₂O × 0.03048
About Feet of Water
One foot of water column (ftH₂O) ≈ 2,989 Pa - the US customary equivalent of cmH₂O used in civil and hydraulic engineering. Municipal water supply systems are designed for 40-80 psi head ≈ 92-184 ft; fire suppression sprinkler systems require minimum 7 psi ≈ 16 ft. Well pump specifications, sump pump head ratings, irrigation mainline pressure, and drainage calculations all use feet of head. 1 ft of water = 12 in WC = 0.4335 psi ≈ 2,989 Pa.
About Technical Atmospheres
One technical atmosphere (at) = exactly 1 kgf/cm² = 98,066.5 Pa ≈ 0.968 standard atmospheres. The metric technical pressure unit used in pre-SI European and Japanese engineering for boilers, hydraulic cylinders, and compressed gas systems. A steam boiler at 10 at operates at 0.981 MPa; hydraulic presses are rated at 200-600 at. Still used parenthetically in old German and Japanese machinery manuals and standards (DIN 1301-3 legacy). Converts simply from kgf/cm²: 1 at ≡ 1 kgf/cm². 1 at = 98,066.5 Pa.
Quick Reference Table
| Feet of Water (ftH₂O) | Technical Atmospheres (at) |
|---|---|
| 1 ftH₂O | 0.03048 at |
| 2 ftH₂O | 0.06096 at |
| 5 ftH₂O | 0.1524 at |
| 10 ftH₂O | 0.3048 at |
| 25 ftH₂O | 0.762 at |
| 50 ftH₂O | 1.524 at |
| 100 ftH₂O | 3.048 at |