square foot per hour
Diffusivityexact by definition
The square foot per hour is exactly 0.09290304/3600 m²/s, that is 2.58064 × 10⁻⁵ m²/s. It is the customary unit for thermal diffusivity in United States heat transfer handbooks, where it pairs with conductivity in Btu/(h·ft·°F) and specific heat in Btu/(lb·°F). The factor is exact by definition.
Watch out: Air's thermal diffusivity is about 0.85 ft²/h and water's about 0.0055 ft²/h, so values in this unit cluster near 1 for gases and near 0.01 for liquids. That makes it easy to lose a factor of ten when transcribing.
| 1 | 25.8064 |
One square foot per hour in every diffusivity unit
| 25,806,400 | square micrometer per second (μm²/s) | |
| 814.388 | square meter per year (m²/yr) | |
| 25.8064 | square millimeter per second (mm²/s) | |
| 25.8064 | centistokes (cSt) | |
| 24 | square foot per day (ft²/d) | |
| 2.22967 | square meter per day (m²/d) | |
| 1 | square foot per hour (ft²/h)this unit | |
| 0.258064 | square centimeter per second (cm²/s) | |
| 0.258064 | stokes (St) | |
| 0.092903 | square meter per hour (m²/h) | |
| 0.04 | square inch per second (in²/s) | |
| 0.000277778 | square foot per second (ft²/s) | |
| 0.0000258064 | square meter per second (m²/s) |
Solvers that use diffusivity