Convert Nanowatt per square metre to International table BTU per hour per square foot
Convert Nanowatt per square metre (nW/m²) to International table BTU per hour per square foot (BTU(IT)/(h·ft²)) instantly and accurately.
Conversion Formula
BTU(IT)/(h·ft²) = nW/m² × 3.169983306e-10
About Nanowatt per square metre
The nanowatt per square metre (nW/m²) equals 10⁻⁹ W/m². Used in astrophysics and cosmology for quantifying extremely weak radiation fields, such as cosmic microwave background intensity and residual thermal emission from near-absolute-zero objects. Relevant in precision cryogenic sensor calibration. 1 nW/m² = 10⁻⁹ W/m² = 10³ pW/m².
About International table BTU per hour per square foot
The international table BTU per hour per square foot (BTU(IT)/(h·ft²)) equals 1055.05585262/(3600×0.09290304) ≈ 3.15459 W/m². The standard US heat flux unit in ASHRAE, ASTM, and building codes for thermal resistance (R-value), boiler ratings, and heat exchanger design. 1 BTU(IT)/(h·ft²) ≈ 3.15459 W/m².
Quick Reference Table
| Nanowatt per square metre (nW/m²) | International table BTU per hour per square foot (BTU(IT)/(h·ft²)) |
|---|---|
| 1 nW/m² | 3.17 × 10-10 BTU(IT)/(h·ft²) |
| 2 nW/m² | 6.34 × 10-10 BTU(IT)/(h·ft²) |
| 5 nW/m² | 1.585 × 10-9 BTU(IT)/(h·ft²) |
| 10 nW/m² | 3.17 × 10-9 BTU(IT)/(h·ft²) |
| 25 nW/m² | 7.925 × 10-9 BTU(IT)/(h·ft²) |
| 50 nW/m² | 1.585 × 10-8 BTU(IT)/(h·ft²) |
| 100 nW/m² | 3.17 × 10-8 BTU(IT)/(h·ft²) |