Btu (th) Inches/second/sq. foot/°F to Btu (it) Inches/hour/sq. foot/°F Converter (Btu (th)·in/(s·ft²·°F) to Btu·in/(h·ft²·°F))
Btu (th)·in/(s·ft²·°F) × 3597.59242144 = Btu·in/(h·ft²·°F)
Calculation: 1 Btu (th)·in/(s·ft²·°F) × 3597.59242144 = 3597.59242144 Btu·in/(h·ft²·°F)
Common BTU (th) inch/second/sq. foot/°F to BTU (IT) inch/hour/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/hour/sq. foot/°F (Btu·in/(h·ft²·°F)).
| Conversion & Equivalent Value | Scientific Notation |
|---|---|
| 0.001 Btu (th)·in/(s·ft²·°F) 3.597592 Btu·in/(h·ft²·°F) | 3.598 × 10⁰ |
| 0.01 Btu (th)·in/(s·ft²·°F) 35.975924 Btu·in/(h·ft²·°F) | 3.598 × 10¹ |
| 0.1 Btu (th)·in/(s·ft²·°F) 359.759242 Btu·in/(h·ft²·°F) | 3.598 × 10² |
| 0.5 Btu (th)·in/(s·ft²·°F) 1798.796211 Btu·in/(h·ft²·°F) | 1.799 × 10³ |
| 1 Btu (th)·in/(s·ft²·°F) 3597.592421 Btu·in/(h·ft²·°F) | 3.598 × 10³ |
| 2 Btu (th)·in/(s·ft²·°F) 7195.184843 Btu·in/(h·ft²·°F) | 7.195 × 10³ |
| 5 Btu (th)·in/(s·ft²·°F) 17987.962107 Btu·in/(h·ft²·°F) | 1.799 × 10⁴ |
| 10 Btu (th)·in/(s·ft²·°F) 35975.924214 Btu·in/(h·ft²·°F) | 3.598 × 10⁴ |
| 20 Btu (th)·in/(s·ft²·°F) 71951.848429 Btu·in/(h·ft²·°F) | 7.195 × 10⁴ |
| 25 Btu (th)·in/(s·ft²·°F) 89939.810536 Btu·in/(h·ft²·°F) | 8.994 × 10⁴ |
| 50 Btu (th)·in/(s·ft²·°F) 179879.621072 Btu·in/(h·ft²·°F) | 1.799 × 10⁵ |
| 100 Btu (th)·in/(s·ft²·°F) 359759.242144 Btu·in/(h·ft²·°F) | 3.598 × 10⁵ |
| 250 Btu (th)·in/(s·ft²·°F) 899398.10536 Btu·in/(h·ft²·°F) | 8.994 × 10⁵ |
| 500 Btu (th)·in/(s·ft²·°F) 1798796.210719 Btu·in/(h·ft²·°F) | 1.799 × 10⁶ |
| 1000 Btu (th)·in/(s·ft²·°F) 3597592.421439 Btu·in/(h·ft²·°F) | 3.598 × 10⁶ |
| Reciprocal & Equivalent Value | Scientific Notation |
|---|---|
| 1 Btu·in/(h·ft²·°F) 0.000277964 Btu (th)·in/(s·ft²·°F) | 2.78 × 10⁻⁴ |
| 5 Btu·in/(h·ft²·°F) 0.00138982 Btu (th)·in/(s·ft²·°F) | 1.39 × 10⁻³ |
| 10 Btu·in/(h·ft²·°F) 0.00277964 Btu (th)·in/(s·ft²·°F) | 2.78 × 10⁻³ |
| 50 Btu·in/(h·ft²·°F) 0.0138982 Btu (th)·in/(s·ft²·°F) | 1.39 × 10⁻² |
| 100 Btu·in/(h·ft²·°F) 0.0277964 Btu (th)·in/(s·ft²·°F) | 2.78 × 10⁻² |
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/hour/sq. foot/°F (Btu·in/(h·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/hour/sq. foot/°F References:
- Stationary atmospheric dry air thermal conductivity at sea level 0.18027 Btu·in/(h·ft²·°F)
- Commercial fiberglass building insulation batt thermal conductivity 0.277339 Btu·in/(h·ft²·°F)
- Liquid drinking water thermal conductivity at room temperature 4.1601 Btu·in/(h·ft²·°F)
- Architectural structural concrete wall thermal conductivity 10.4002 Btu·in/(h·ft²·°F)
How to Convert BTU (th) inch/second/sq. foot/°F to BTU (IT) inch/hour/sq. foot/°F
Converting BTU (th) inch/second/sq. foot/°F (Btu (th)·in/(s·ft²·°F)) to BTU (IT) inch/hour/sq. foot/°F (Btu·in/(h·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 3597.592421 BTU (IT) inch/hour/sq. foot/°F, while 1 Btu·in/(h·ft²·°F) equals 0.000277964 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/(h·ft²·°F) = 0.144228 watt per meter kelvin (W/(m·K))V(Btu·in/(h·ft²·°F)) = V(Btu (th)·in/(s·ft²·°F)) × ( 518.8732 / 0.144228 ) = V(Btu (th)·in/(s·ft²·°F)) × 3597.592421Value in BTU (IT) inch/hour/sq. foot/°F = Value in BTU (th) inch/second/sq. foot/°F × 3597.59242144Direct computational formula applied for standard conversion.Evaluating an input of 120 BTU (th) inch/second/sq. foot/°F (Btu (th)·in/(s·ft²·°F)) produces 431711.090573 BTU (IT) inch/hour/sq. foot/°F (Btu·in/(h·ft²·°F)). In heavy-duty utility and industrial workloads, 2500 Btu (th)·in/(s·ft²·°F) equals 8993981.053596 Btu·in/(h·ft²·°F).
Inverse check: 1 Btu·in/(h·ft²·°F) = 0.000277964 Btu (th)·in/(s·ft²·°F).Understanding BTU (th) inch/second/sq. foot/°F and BTU (IT) inch/hour/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/hour/sq. foot/°F
Btu·in/(h·ft²·°F)A BTU (IT) inch/hour/sq. foot/°F (Btu·in/(h·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 0.18027 Btu·in/(h·ft²·°F), a commercial fiberglass building insulation batt thermal conductivity equals 0.277339 Btu·in/(h·ft²·°F), a liquid drinking water thermal conductivity at room temperature equals 4.1601 Btu·in/(h·ft²·°F).
A physical magnitude of 1 Btu·in/(h·ft²·°F) corresponds to 0.144228 W/(m·K) in standard SI measurement.
1 Btu·in/(h·ft²·°F) = 0.144228 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).
