Convert International table BTU per hour per square foot to Nanowatt per square metre
Convert International table BTU per hour per square foot (BTU(IT)/(h·ft²)) to Nanowatt per square metre (nW/m²) instantly and accurately.
Conversion Formula
nW/m² = BTU(IT)/(h·ft²) × 3154590745
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.
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.
Quick Reference Table
| International table BTU per hour per square foot (BTU(IT)/(h·ft²)) | Nanowatt per square metre (nW/m²) |
|---|---|
| 1 BTU(IT)/(h·ft²) | 3.155 × 109 nW/m² |
| 2 BTU(IT)/(h·ft²) | 6.309 × 109 nW/m² |
| 5 BTU(IT)/(h·ft²) | 1.577 × 1010 nW/m² |
| 10 BTU(IT)/(h·ft²) | 3.155 × 1010 nW/m² |
| 25 BTU(IT)/(h·ft²) | 7.886 × 1010 nW/m² |
| 50 BTU(IT)/(h·ft²) | 1.577 × 1011 nW/m² |
| 100 BTU(IT)/(h·ft²) | 3.155 × 1011 nW/m² |