Convert Square millimetres per hour to Square feet per second
Convert Square millimetres per hour (mm²/h) to Square feet per second (ft²/s) instantly and accurately.
Conversion Formula
ft²/s = mm²/h × 2.989975116e-9
About Square millimetres per hour
The square millimetre per hour (mm²/h) equals 1/3 600 000 000 m²/s, the smallest practical thermal diffusivity unit. It is used in very slow heat-transfer processes such as diffusion through frozen soils or phase-change materials studied over many hours. Heavy clay soils can show diffusivity values of 1-2 mm²/h. 1 mm²/h = 1e-6/3600 m²/s.
About Square feet per second
The square foot per second (ft²/s) equals 0.09290304 m²/s, the imperial base unit for thermal diffusivity analogous to m²/s. It is used in US aerospace engineering and combustion research for highly conductive materials and high-temperature plasmas. Diamond, the most thermally diffusive solid at ≈7 cm²/s, converts to ≈0.0075 ft²/s; silver to ≈0.00167 ft²/s. 1 ft²/s = 3600 ft²/h = 0.09290304 m²/s.
Quick Reference Table
| Square millimetres per hour (mm²/h) | Square feet per second (ft²/s) |
|---|---|
| 1 mm²/h | 2.99 × 10-9 ft²/s |
| 2 mm²/h | 5.98 × 10-9 ft²/s |
| 5 mm²/h | 1.495 × 10-8 ft²/s |
| 10 mm²/h | 2.99 × 10-8 ft²/s |
| 25 mm²/h | 7.475 × 10-8 ft²/s |
| 50 mm²/h | 1.495 × 10-7 ft²/s |
| 100 mm²/h | 2.99 × 10-7 ft²/s |