Btus (th)/second/sq. inch to Btus (IT)/hour/sq. foot Converter (Btu/(s·in²) to Btu/(h·ft²))
Btu/(s·in²) × 518053.23933981 = Btu/(h·ft²)
Calculation: 1 Btu/(s·in²) × 518053.23933981 = 518053.23933981 Btu/(h·ft²)
Common BTU (th)/second/sq. inch to BTU (IT)/hour/sq. foot Calculations
Quick-lookup reference table showing calculated equivalents for standard increments between BTU (th)/second/sq. inch (Btu/(s·in²)) and BTU (IT)/hour/sq. foot (Btu/(h·ft²)).
| Conversion & Equivalent Value | Scientific Notation |
|---|---|
| 0.001 Btu/(s·in²) 518.053239 Btu/(h·ft²) | 5.181 × 10² |
| 0.01 Btu/(s·in²) 5180.532393 Btu/(h·ft²) | 5.181 × 10³ |
| 0.1 Btu/(s·in²) 51805.323934 Btu/(h·ft²) | 5.181 × 10⁴ |
| 0.5 Btu/(s·in²) 259026.61967 Btu/(h·ft²) | 2.59 × 10⁵ |
| 1 Btu/(s·in²) 518053.23934 Btu/(h·ft²) | 5.181 × 10⁵ |
| 2 Btu/(s·in²) 1036106.47868 Btu/(h·ft²) | 1.036 × 10⁶ |
| 5 Btu/(s·in²) 2590266.196699 Btu/(h·ft²) | 2.59 × 10⁶ |
| 10 Btu/(s·in²) 5180532.393398 Btu/(h·ft²) | 5.181 × 10⁶ |
| 20 Btu/(s·in²) 1.036106 × 10⁷ Btu/(h·ft²) | 1.036 × 10⁷ |
| 25 Btu/(s·in²) 1.295133 × 10⁷ Btu/(h·ft²) | 1.295 × 10⁷ |
| 50 Btu/(s·in²) 2.590266 × 10⁷ Btu/(h·ft²) | 2.59 × 10⁷ |
| 100 Btu/(s·in²) 5.180532 × 10⁷ Btu/(h·ft²) | 5.181 × 10⁷ |
| 250 Btu/(s·in²) 1.295133 × 10⁸ Btu/(h·ft²) | 1.295 × 10⁸ |
| 500 Btu/(s·in²) 2.590266 × 10⁸ Btu/(h·ft²) | 2.59 × 10⁸ |
| 1000 Btu/(s·in²) 5.180532 × 10⁸ Btu/(h·ft²) | 5.181 × 10⁸ |
| Reciprocal & Equivalent Value | Scientific Notation |
|---|---|
| 1 Btu/(h·ft²) 1.930304 × 10⁻⁶ Btu/(s·in²) | 1.93 × 10⁻⁶ |
| 5 Btu/(h·ft²) 9.651518 × 10⁻⁶ Btu/(s·in²) | 9.652 × 10⁻⁶ |
| 10 Btu/(h·ft²) 1.930304 × 10⁻⁵ Btu/(s·in²) | 1.93 × 10⁻⁵ |
| 50 Btu/(h·ft²) 9.651518 × 10⁻⁵ Btu/(s·in²) | 9.652 × 10⁻⁵ |
| 100 Btu/(h·ft²) 0.00019303 Btu/(s·in²) | 1.93 × 10⁻⁴ |
Real-World Context & Everyday Benchmarks
Tap to load into converterTo help contextualize these units in everyday life, science, and engineering, here are verified real-world reference points for BTU (th)/second/sq. inch (Btu/(s·in²)) and BTU (IT)/hour/sq. foot (Btu/(h·ft²)):
BTU (th)/second/sq. inch References:
- Solar constant extraterrestrial solar irradiance at top of atmosphere 0.000833 Btu/(s·in²)
- Clear sky direct midday summer sunlight striking sea level ground 0.000612 Btu/(s·in²)
- Human body resting thermal metabolic heat radiation to room 3.1E-5 Btu/(s·in²)
- Overcast winter day diffuse solar irradiance at sea level 6.1E-5 Btu/(s·in²)
BTU (IT)/hour/sq. foot References:
- Solar constant extraterrestrial solar irradiance at top of atmosphere 431.43 Btu/(h·ft²)
- Clear sky direct midday summer sunlight striking sea level ground 317 Btu/(h·ft²)
- Human body resting thermal metabolic heat radiation to room 15.8499 Btu/(h·ft²)
- Overcast winter day diffuse solar irradiance at sea level 31.6998 Btu/(h·ft²)
How to Convert BTU (th)/second/sq. inch to BTU (IT)/hour/sq. foot
Converting BTU (th)/second/sq. inch (Btu/(s·in²)) to BTU (IT)/hour/sq. foot (Btu/(h·ft²)) is a core calculation in Heat Flux Density, which measures the rate of thermal energy transfer radiating or conducting through a unit area per second. This calculation navigates the boundary between the International Metric System (SI) and British Imperial / US Customary engineering standards. In contemporary metrology, Imperial units are defined in terms of exact SI standards via international agreements—notably NIST SP 811 and the 1959 International Yard and Pound Agreement. Exactly 1 BTU (th)/second/sq. inch equals 518053.23934 BTU (IT)/hour/sq. foot, while 1 Btu/(h·ft²) equals 1.930304 × 10⁻⁶ Btu/(s·in²).
Mathematical Conversion Derivation via Coherent SI Base Unit
Under the International System of Quantities (ISQ), dimensional conversion between non-SI units is rigorously resolved by bridging through the coherent SI base unit (watt per square meter (W/m²)) without arbitrary rounding:
1 Btu/(s·in²) = 1634246 watt per square meter (W/m²)1 Btu/(h·ft²) = 3.154591 watt per square meter (W/m²)V(Btu/(h·ft²)) = V(Btu/(s·in²)) × ( 1634246 / 3.154591 ) = V(Btu/(s·in²)) × 518053.23934Value in BTU (IT)/hour/sq. foot = Value in BTU (th)/second/sq. inch × 518053.23933981Direct computational formula applied for standard conversion.Evaluating an input of 12 BTU (th)/second/sq. inch (Btu/(s·in²)) produces 6216638.872078 BTU (IT)/hour/sq. foot (Btu/(h·ft²)). In heavy-duty utility and industrial workloads, 2500 Btu/(s·in²) equals 1.295133 × 10⁹ Btu/(h·ft²).
Inverse check: 1 Btu/(h·ft²) = 1.930304 × 10⁻⁶ Btu/(s·in²).Understanding BTU (th)/second/sq. inch and BTU (IT)/hour/sq. foot
BTU (th)/second/sq. inch
Btu/(s·in²)A BTU (th)/second/sq. inch (Btu/(s·in²)) is an imperial and US customary unit for heat flux density.
Applications & Practical Context
In practical heat flux density terms, a solar constant extraterrestrial solar irradiance at top of atmosphere equals 0.000833 Btu/(s·in²), a clear sky direct midday summer sunlight striking sea level ground equals 0.000612 Btu/(s·in²), a human body resting thermal metabolic heat radiation to room equals 3.1 × 10⁻⁵ Btu/(s·in²).
A physical magnitude of 1 Btu/(s·in²) corresponds to 1634246 W/m² in standard SI measurement.
1 Btu/(s·in²) = 1634246 W/m²BTU (IT)/hour/sq. foot
Btu/(h·ft²)A BTU (IT)/hour/sq. foot (Btu/(h·ft²)) is an imperial and US customary unit for heat flux density.
Applications & Practical Context
In practical heat flux density terms, a solar constant extraterrestrial solar irradiance at top of atmosphere equals 431.43 Btu/(h·ft²), a clear sky direct midday summer sunlight striking sea level ground equals 317 Btu/(h·ft²), a human body resting thermal metabolic heat radiation to room equals 15.8499 Btu/(h·ft²).
A physical magnitude of 1 Btu/(h·ft²) corresponds to 3.154591 W/m² in standard SI measurement.
1 Btu/(h·ft²) = 3.154591 W/m²Domain Metrology & Engineering Applications
Thermal Transmission Flux (q = Q̇ / A)
Rigorously quantified in laboratory and field settings using Schmidt-Boelter heat flux gauges, differential thermopile foil transducers, and calibrated Gardon radiant gauges.
Applied across rocket nozzle combustion chamber analysis, fire resistance testing (ASTM E119), furnace wall heat loss auditing, and hypersonic aerothermal design under international metrology standard ISO 80000-5:2019, ASME PTC 19.3.
Formulas, conversion coefficients, and base definitions on this page strictly adhere to the ISO 80000-5:2019, ASME PTC 19.3 and the BIPM SI Brochure (9th Edition). Governed by Thermal Transmission Flux (q = Q̇ / A) under ISO 80000 dimensional vector [M T⁻³].
Heat Flux Density to Total Thermal Power Bridge (Watts • Kilowatts • Megawatts • BTU/h • Horsepower)
Calculate total continuous heat dissipation power P = q" × A across surface barriers and exchangers, bridging heat flux density [M T⁻³] with thermal power [M L² T⁻³].
P = q" × A
[W/m²] × [m²] → [W]
-
1. Normalize Input to SI Base Unit (W/m²):
q" = 1 Btu/(s·in²) × 1634246 = 1634246 W/m² -
2. Apply Engineering Parameter (A):
Selected condition: Industrial Hydronic Radiator Panel (8 m²) at A = 8 m² -
3. Execute Governing Physical Law in SI Units:
P = q" × A = (1634246 W/m²) × (8 m²) = 1.307397 × 10⁷ W -
4. Convert to Standard Engineering Units:
• W: 1.307397 × 10⁷ × 1 = 1.3074 × 10⁷ W (Watts) • kW: 1.307397 × 10⁷ × 0.001 = 13073.968 kW (Kilowatts) • MW: 1.307397 × 10⁷ × 1 × 10⁻⁶ = 13.073968 MW (Megawatts) • hp: 1.307397 × 10⁷ × 0.001341 = 17532.4799 hp (Horsepower (Mechanical)) • PS: 1.307397 × 10⁷ × 0.00136 = 17775.6496 PS (Metric Horsepower (PS)) • BTU/h: 1.307397 × 10⁷ × 3.4121 = 4.46 × 10⁷ BTU/h (BTU per Hour)
| Engineering Substance / Operating Standard | Parameter Value (m²) | Reference State / Condition | Typical Industrial & Engineering Application |
|---|---|---|---|
| Residential Window Glazing (4 m²) | 4 |
4.0 m² | Double-pane exterior window glass aperture |
| Industrial Hydronic Radiator Panel (8 m²) | 8 |
8.0 m² | Convective space heating radiator surface |
| Shell & Tube Heat Exchanger (50 m²) | 50 |
50.0 m² | Industrial process fluid cooling bundle |
| Power Boiler Waterwall (200 m²) | 200 |
200.0 m² | Thermal power plant steam generator wall |
Frequently Asked Questions
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