Btu (th) Inches/second/sq. foot/°F to Btu (it) Inches/second/sq. foot/°F Converter (Btu (th)·in/(s·ft²·°F) to Btu·in/(s·ft²·°F))
Btu (th)·in/(s·ft²·°F) × 0.99933131 = Btu·in/(s·ft²·°F)
Calculation: 1 Btu (th)·in/(s·ft²·°F) × 0.99933131 = 0.99933131 Btu·in/(s·ft²·°F)
Common BTU (th) inch/second/sq. foot/°F to BTU (IT) inch/second/sq. foot/°F Calculations
Quick-lookup reference table showing calculated equivalents for standard increments between BTU (th) inch/second/sq. foot/°F (Btu (th)·in/(s·ft²·°F)) and BTU (IT) inch/second/sq. foot/°F (Btu·in/(s·ft²·°F)).
| Conversion & Equivalent Value | Scientific Notation |
|---|---|
| 0.001 Btu (th)·in/(s·ft²·°F) 0.000999331 Btu·in/(s·ft²·°F) | 9.993 × 10⁻⁴ |
| 0.01 Btu (th)·in/(s·ft²·°F) 0.00999331 Btu·in/(s·ft²·°F) | 9.993 × 10⁻³ |
| 0.1 Btu (th)·in/(s·ft²·°F) 0.0999331 Btu·in/(s·ft²·°F) | 9.993 × 10⁻² |
| 0.5 Btu (th)·in/(s·ft²·°F) 0.499666 Btu·in/(s·ft²·°F) | 4.997 × 10⁻¹ |
| 1 Btu (th)·in/(s·ft²·°F) 0.999331 Btu·in/(s·ft²·°F) | 9.993 × 10⁻¹ |
| 2 Btu (th)·in/(s·ft²·°F) 1.998663 Btu·in/(s·ft²·°F) | 1.999 × 10⁰ |
| 5 Btu (th)·in/(s·ft²·°F) 4.996657 Btu·in/(s·ft²·°F) | 4.997 × 10⁰ |
| 10 Btu (th)·in/(s·ft²·°F) 9.993313 Btu·in/(s·ft²·°F) | 9.993 × 10⁰ |
| 20 Btu (th)·in/(s·ft²·°F) 19.986626 Btu·in/(s·ft²·°F) | 1.999 × 10¹ |
| 25 Btu (th)·in/(s·ft²·°F) 24.983283 Btu·in/(s·ft²·°F) | 2.498 × 10¹ |
| 50 Btu (th)·in/(s·ft²·°F) 49.966565 Btu·in/(s·ft²·°F) | 4.997 × 10¹ |
| 100 Btu (th)·in/(s·ft²·°F) 99.933131 Btu·in/(s·ft²·°F) | 9.993 × 10¹ |
| 250 Btu (th)·in/(s·ft²·°F) 249.832826 Btu·in/(s·ft²·°F) | 2.498 × 10² |
| 500 Btu (th)·in/(s·ft²·°F) 499.665653 Btu·in/(s·ft²·°F) | 4.997 × 10² |
| 1000 Btu (th)·in/(s·ft²·°F) 999.331305 Btu·in/(s·ft²·°F) | 9.993 × 10² |
| Reciprocal & Equivalent Value | Scientific Notation |
|---|---|
| 1 Btu·in/(s·ft²·°F) 1.000669 Btu (th)·in/(s·ft²·°F) | 1.001 × 10⁰ |
| 5 Btu·in/(s·ft²·°F) 5.003346 Btu (th)·in/(s·ft²·°F) | 5.003 × 10⁰ |
| 10 Btu·in/(s·ft²·°F) 10.006691 Btu (th)·in/(s·ft²·°F) | 1.001 × 10¹ |
| 50 Btu·in/(s·ft²·°F) 50.033457 Btu (th)·in/(s·ft²·°F) | 5.003 × 10¹ |
| 100 Btu·in/(s·ft²·°F) 100.066914 Btu (th)·in/(s·ft²·°F) | 1.001 × 10² |
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) inch/second/sq. foot/°F (Btu (th)·in/(s·ft²·°F)) and BTU (IT) inch/second/sq. foot/°F (Btu·in/(s·ft²·°F)):
BTU (th) inch/second/sq. foot/°F References:
- Stationary atmospheric dry air thermal conductivity at sea level 5.0E-5 Btu (th)·in/(s·ft²·°F)
- Commercial fiberglass building insulation batt thermal conductivity 7.7E-5 Btu (th)·in/(s·ft²·°F)
- Liquid drinking water thermal conductivity at room temperature 0.001156 Btu (th)·in/(s·ft²·°F)
- Architectural structural concrete wall thermal conductivity 0.002891 Btu (th)·in/(s·ft²·°F)
BTU (IT) inch/second/sq. foot/°F References:
- Stationary atmospheric dry air thermal conductivity at sea level 5.0E-5 Btu·in/(s·ft²·°F)
- Commercial fiberglass building insulation batt thermal conductivity 7.7E-5 Btu·in/(s·ft²·°F)
- Liquid drinking water thermal conductivity at room temperature 0.001156 Btu·in/(s·ft²·°F)
- Architectural structural concrete wall thermal conductivity 0.002889 Btu·in/(s·ft²·°F)
How to Convert BTU (th) inch/second/sq. foot/°F to BTU (IT) inch/second/sq. foot/°F
Converting BTU (th) inch/second/sq. foot/°F (Btu (th)·in/(s·ft²·°F)) to BTU (IT) inch/second/sq. foot/°F (Btu·in/(s·ft²·°F)) is a core calculation in Thermal Conductivity, which measures a material's intrinsic capacity to conduct and transfer heat through microscopic collisions. 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) inch/second/sq. foot/°F equals 0.999331 BTU (IT) inch/second/sq. foot/°F, while 1 Btu·in/(s·ft²·°F) equals 1.000669 Btu (th)·in/(s·ft²·°F).
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 meter kelvin (W/(m·K))) without arbitrary rounding:
1 Btu (th)·in/(s·ft²·°F) = 518.8732 watt per meter kelvin (W/(m·K))1 Btu·in/(s·ft²·°F) = 519.2204 watt per meter kelvin (W/(m·K))V(Btu·in/(s·ft²·°F)) = V(Btu (th)·in/(s·ft²·°F)) × ( 518.8732 / 519.2204 ) = V(Btu (th)·in/(s·ft²·°F)) × 0.999331Value in BTU (IT) inch/second/sq. foot/°F = Value in BTU (th) inch/second/sq. foot/°F × 0.99933131Direct computational formula applied for standard conversion.To convert 24 BTU (th) inch/second/sq. foot/°F (Btu (th)·in/(s·ft²·°F)) to BTU (IT) inch/second/sq. foot/°F (Btu·in/(s·ft²·°F)): multiply 24 by 0.999331 to get 23.983951 Btu·in/(s·ft²·°F). At an industrial engineering scale, 100 Btu (th)·in/(s·ft²·°F) converts to 99.933131 Btu·in/(s·ft²·°F).
Inverse check: 1 Btu·in/(s·ft²·°F) = 1.000669 Btu (th)·in/(s·ft²·°F).Understanding BTU (th) inch/second/sq. foot/°F and BTU (IT) inch/second/sq. foot/°F
BTU (th) inch/second/sq. foot/°F
Btu (th)·in/(s·ft²·°F)A BTU (th) inch/second/sq. foot/°F (Btu (th)·in/(s·ft²·°F)) is an imperial and US customary unit for thermal conductivity.
Applications & Practical Context
In practical thermal conductivity terms, a stationary atmospheric dry air thermal conductivity at sea level equals 5 × 10⁻⁵ Btu (th)·in/(s·ft²·°F), a commercial fiberglass building insulation batt thermal conductivity equals 7.7 × 10⁻⁵ Btu (th)·in/(s·ft²·°F), a liquid drinking water thermal conductivity at room temperature equals 0.001156 Btu (th)·in/(s·ft²·°F).
A physical magnitude of 1 Btu (th)·in/(s·ft²·°F) corresponds to 518.8732 W/(m·K) in standard SI measurement.
1 Btu (th)·in/(s·ft²·°F) = 518.8732 W/(m·K)BTU (IT) inch/second/sq. foot/°F
Btu·in/(s·ft²·°F)A BTU (IT) inch/second/sq. foot/°F (Btu·in/(s·ft²·°F)) is an imperial and US customary unit for thermal conductivity.
Applications & Practical Context
In practical thermal conductivity terms, a stationary atmospheric dry air thermal conductivity at sea level equals 5 × 10⁻⁵ Btu·in/(s·ft²·°F), a commercial fiberglass building insulation batt thermal conductivity equals 7.7 × 10⁻⁵ Btu·in/(s·ft²·°F), a liquid drinking water thermal conductivity at room temperature equals 0.001156 Btu·in/(s·ft²·°F).
A physical magnitude of 1 Btu·in/(s·ft²·°F) corresponds to 519.2204 W/(m·K) in standard SI measurement.
1 Btu·in/(s·ft²·°F) = 519.2204 W/(m·K)Domain Metrology & Engineering Applications
Fourier's Law of Heat Conduction (q = -k · ∇T)
Rigorously quantified in laboratory and field settings using guarded hot plate apparatus (ASTM C177), laser flash thermal diffusivity analyzers, and transient plane source (TPS) sensors.
Applied across thermal interface material (TIM) development, architectural insulation manufacturing, aerospace heat shield design, and refractory ceramics under international metrology standard ISO 80000-5:2019, ASTM C177.
Formulas, conversion coefficients, and base definitions on this page strictly adhere to the ISO 80000-5:2019, ASTM C177 and the BIPM SI Brochure (9th Edition). Governed by Fourier's Law of Heat Conduction (q = -k · ∇T) under ISO 80000 dimensional vector [M L T⁻³ Θ⁻¹].
Thermal Conductivity to Heat Flux Density Bridge (W/m² • kW/m² • BTU/(h·ft²) • cal/(s·cm²))
Calculate Fourier conduction heat flux q" = k × ∇T across building envelopes and industrial heat exchangers, bridging thermal conductivity [M L T⁻³ Θ⁻¹] with heat flux density [M T⁻³].
q" = k × ∇T
[W/(m·K)] × [K/m] → [W/m²]
-
1. Normalize Input to SI Base Unit (W/(m·K)):
k = 1 Btu (th)·in/(s·ft²·°F) × 518.8732 = 518.8732 W/(m·K) -
2. Apply Engineering Parameter (∇T):
Selected condition: Insulated Wall Core (20K across 0.1m = 200 K/m) at ∇T = 200 K/m -
3. Execute Governing Physical Law in SI Units:
q" = k × ∇T = (518.8732 W/(m·K)) × (200 K/m) = 103774.64 W/m² -
4. Convert to Standard Engineering Units:
• W/m²: 103774.64 × 1 = 103774.64 W/m² (Watts per Square Meter) • kW/m²: 103774.64 × 0.001 = 103.7746 kW/m² (Kilowatts per Square Meter) • BTU/(h·ft²): 103774.64 × 0.317 = 32896.3944 BTU/(h·ft²) (BTU per Hour Sq. Foot) • cal/(s·cm²): 103774.64 × 2.3885 × 10⁻⁵ = 2.478615 cal/(s·cm²) (Calories per Second Sq. Cm) • Ly/min: 103774.64 × 0.001433 = 148.7436 Ly/min (Langley per Minute) • MW/m²: 103774.64 × 1 × 10⁻⁶ = 0.103775 MW/m² (Megawatts per Square Meter)
| Engineering Substance / Operating Standard | Parameter Value (K/m) | Reference State / Condition | Typical Industrial & Engineering Application |
|---|---|---|---|
| Insulated Wall Core (20K across 0.1m = 200 K/m) | 200 |
200 K/m | Standard residential fiberglass/mineral wool batt |
| Solid Brick Masonry (25K across 0.25m = 100 K/m) | 100 |
100 K/m | Architectural structural brick veneer wall |
| Steam Boiler Tube Wall (100K across 0.005m = 20,000 K/m) | 20000 |
20,000 K/m | Carbon steel heat recovery steam boiler tube |
| CPU Copper Heat Spreader (30K across 0.002m = 15,000 K/m) | 15000 |
15,000 K/m | Semiconductor thermal interface heat spreader |
Frequently Asked Questions
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Physically Coupled Thermodynamics & Heat Converters
Explore interconnected physical dimension converters within the Thermodynamics & Heat cluster (ISO 80000-5:2019).
