Heat Transfer Coefficient Converter
Convert between heat transfer coefficient units including Watts per square meter Kelvin and BTU per hour square foot Fahrenheit.
Result
1 W/(m²·K = 0.1761102873 IT
Understanding Heat Transfer Coefficient Units: Watt per Square Meter Kelvin and Convection Coefficient
Heat transfer coefficient converters are essential tools for calculating convection coefficients, film coefficients, and surface thermal conductance in heat transfer analysis. Whether you're working with watts per square meter kelvin (W/(m²·K)), watts per square meter celsius (W/(m²·°C)), calories per second per square centimeter per celsius (cal/(s·cm²·°C)), kilocalories per hour per square meter per celsius (kcal/(h·m²·°C)), British thermal units per hour per square foot per fahrenheit (Btu/(h·ft²·°F)), Btu per second per square foot per fahrenheit (Btu/(s·ft²·°F)), or any of eleven heat transfer coefficient units, understanding convection coefficient conversions is crucial for engineers, scientists, and analysts in HVAC, thermal engineering, building design, electronics cooling, and heat exchanger design industries.
Heat transfer coefficient measurements quantify the rate of convective heat transfer per unit area per unit temperature difference, representing Newton's law of cooling proportionality constant. From natural convection coefficients at 5-25 W/(m²·K) to forced convection at 25-250 W/(m²·K), and from water convection at 500-10,000 W/(m²·K) to boiling heat transfer at 2,500-100,000 W/(m²·K), this comprehensive converter supports eleven heat transfer coefficient units with instant, accurate results for all your convection, heat exchanger, and thermal design calculations across different measurement systems.
How to Convert Heat Transfer Coefficient Units: Formulas and Methods
Watt per Square Meter Kelvin to Celsius Conversions
Converting from watts per square meter kelvin (W/(m²·K)) to watts per square meter celsius (W/(m²·°C)) uses a 1:1 ratio, since the kelvin and celsius temperature scales have the same unit size for temperature differences. For example, a convection coefficient of 50 W/(m²·K) equals 50 W/(m²·°C). Converting from joules per second per square meter kelvin (J/(s·m²·K)) to W/(m²·K) also uses a 1:1 ratio, since 1 joule per second equals 1 watt by definition.
Calorie-Based Heat Transfer Coefficient Units
Converting from W/(m²·K) to calorie IT per second per square centimeter per celsius (cal(IT)/(s·cm²·°C)) divides by 41840, since 1 cal(IT)/(s·cm²·°C) equals 41840 W/(m²·K). This conversion accounts for the calorie-to-joule conversion (1 cal = 4.184 J), the area conversion (1 m² = 10,000 cm²), and the time conversion (1 s = 1 s). For hour-based units, kilocalorie IT per hour per square meter per celsius (kcal(IT)/(h·m²·°C)) equals 1.163 W/(m²·K), and kilocalorie IT per hour per square foot per fahrenheit (kcal(IT)/(h·ft²·°F)) equals 12.518 W/(m²·K), accounting for area and temperature scale differences.
British Thermal Unit per Square Foot Conversions
Converting from W/(m²·K) to Btu IT per hour per square foot per fahrenheit (Btu(IT)/(h·ft²·°F)) multiplies by 0.176, since 1 Btu(IT)/(h·ft²·°F) equals 5.67826 W/(m²·K). This conversion accounts for energy (1 Btu = 1055.06 J), time (1 hour = 3600 s), area (1 ft² = 0.092903 m²), and temperature scale (1 °F = 5/9 K). For second-based units, Btu(IT)/(s·ft²·°F) equals 20428.8 W/(m²·K) (multiply hourly by 3600), and the thermochemical variants differ slightly: Btu(th)/(h·ft²·°F) equals 5.67447 W/(m²·K) and Btu(th)/(s·ft²·°F) equals 20415.7 W/(m²·K), reflecting the small Btu definition difference (1054.35 J for th).
Newton's Law of Cooling and Heat Transfer Coefficient
Heat transfer coefficient (h) relates heat flux (q) to temperature difference (ΔT) through Newton's law of cooling: q = h × ΔT. Higher heat transfer coefficients indicate more efficient convective heat transfer. Typical values range from 5-25 W/(m²·K) for natural convection in air, 25-250 W/(m²·K) for forced air convection, 500-10,000 W/(m²·K) for water convection, and 2,500-100,000 W/(m²·K) for boiling or condensation. Converting between unit systems helps engineers compare international heat exchanger specifications and thermal design standards.
Heat Transfer Coefficient Versus Thermal Conductivity
Heat transfer coefficient (h, W/(m²·K)) describes convective heat transfer at surfaces, while thermal conductivity (k, W/(m·K)) describes conductive heat transfer through materials. Heat transfer coefficient depends on fluid properties, flow conditions, and surface geometry, while thermal conductivity is a material property. The relationship q = h × ΔT applies to convection, while Fourier's law q = k × (ΔT/Δx) applies to conduction. Converting units helps engineers work with both properties in combined conduction-convection heat transfer problems.
Heat Transfer Coefficient Conversion Reference Table
| W/(m²·K) | W/(m²·°C) | cal(IT)/(s·cm²·°C) | kcal(IT)/(h·m²·°C) | Btu(IT)/(h·ft²·°F) | Btu(IT)/(s·ft²·°F) |
|---|---|---|---|---|---|
| 1 | 1 | 0.000024 | 0.860 | 0.176 | 0.000049 |
| 5 | 5 | 0.000120 | 4.300 | 0.881 | 0.000245 |
| 10 | 10 | 0.000239 | 8.600 | 1.762 | 0.000490 |
| 25 | 25 | 0.000598 | 21.50 | 4.404 | 0.001224 |
| 50 | 50 | 0.001195 | 43.00 | 8.808 | 0.002448 |
| 100 | 100 | 0.002390 | 86.00 | 17.62 | 0.004895 |
| 250 | 250 | 0.005976 | 215.0 | 44.04 | 0.01224 |
| 500 | 500 | 0.01195 | 430.0 | 88.08 | 0.02448 |
| 1000 | 1000 | 0.02390 | 860.0 | 176.2 | 0.04895 |
| 41840 | 41840 | 1.000 | 35982 | 7371 | 2.048 |
Typical Heat Transfer Coefficient Values by Application
| Application | W/(m²·K) | Btu/(h·ft²·°F) |
|---|---|---|
| Natural convection (air, vertical surface) | 5-25 | 0.9-4.4 |
| Forced convection (air, flat plate) | 25-250 | 4.4-44 |
| Natural convection (water, vertical surface) | 500-2000 | 88-352 |
| Forced convection (water, pipe flow) | 1000-10000 | 176-1762 |
| Boiling water (nucleate) | 2500-35000 | 440-6166 |
| Condensing steam | 5000-100000 | 881-17620 |
| Electronic cooling (forced air) | 10-100 | 1.8-17.6 |
| Building walls (indoor air) | 8-12 | 1.4-2.1 |
Industry Applications and Use Cases
HVAC and Building Energy Performance
HVAC engineers use heat transfer coefficients in W/(m²·K) or Btu/(h·ft²·°F) to calculate heat loss through building envelopes, size heating and cooling systems, and evaluate thermal performance. Typical indoor air convection coefficients range from 8-12 W/(m²·K) (1.4-2.1 Btu/(h·ft²·°F)) for building walls. Converting between unit systems helps engineers compare international building codes, energy standards, and HVAC equipment specifications when designing efficient building systems.
Heat Exchanger Design and Process Engineering
Process engineers use heat transfer coefficients in W/(m²·K) or cal/(s·cm²·°C) to design heat exchangers, evaluate thermal performance, and calculate heat transfer rates. Typical values range from 500-10,000 W/(m²·K) for water convection to 5,000-100,000 W/(m²·K) for condensing steam. Converting between W/(m²·K), Btu/(h·ft²·°F), and cal/(s·cm²·°C) enables comparing international heat exchanger specifications and thermal design parameters across different manufacturers.
Electronic Cooling and Thermal Management
Electronics engineers calculate heat transfer coefficients in W/(m²·K) to design cooling systems, evaluate thermal performance, and prevent component overheating. Forced air convection for electronics typically ranges from 10-100 W/(m²·K) (1.8-17.6 Btu/(h·ft²·°F)). Converting between unit systems helps engineers size heat sinks, fans, and liquid cooling systems when working with international component specifications and thermal design standards for modern processors and power electronics.
Boiling and Condensation Heat Transfer
Thermal engineers use heat transfer coefficients for boiling and condensation processes in power generation, refrigeration, and chemical processing. Nucleate boiling coefficients range from 2,500-35,000 W/(m²·K) (440-6,166 Btu/(h·ft²·°F)), while condensing steam coefficients range from 5,000-100,000 W/(m²·K) (881-17,620 Btu/(h·ft²·°F)). Converting units helps engineers design boilers, condensers, and phase-change heat exchangers when working with international thermal design standards.
Frequently Asked Questions
What is heat transfer coefficient and how does it differ from thermal conductivity?
Heat transfer coefficient (h, W/(m²·K)) describes convective heat transfer at surfaces, relating heat flux to temperature difference through Newton's law: q = h × ΔT. Thermal conductivity (k, W/(m·K)) describes conductive heat transfer through materials via Fourier's law: q = k × (ΔT/Δx). Heat transfer coefficient depends on fluid properties and flow conditions, while thermal conductivity is a material property.
How do I convert W/(m²·K) to Btu/(h·ft²·°F)?
Multiply W/(m²·K) by 0.176 to get Btu(IT)/(h·ft²·°F), since 1 Btu(IT)/(h·ft²·°F) equals 5.67826 W/(m²·K). For example, a convection coefficient of 50 W/(m²·K) equals 8.81 Btu/(h·ft²·°F), and 100 W/(m²·K) equals 17.62 Btu/(h·ft²·°F) for HVAC and building energy calculations.
How to convert W/(m²·K) to W/(m²·°C)?
Use a 1:1 ratio, since the kelvin and celsius temperature scales have the same unit size for temperature differences. For example, 50 W/(m²·K) equals 50 W/(m²·°C), and 100 W/(m²·K) equals 100 W/(m²·°C). This applies because ΔT in kelvins equals ΔT in celsius degrees.
How to convert to calorie-based heat transfer coefficient units?
Calorie IT per second per square centimeter per celsius equals 41840 W/(m²·K). For hour-based units, kilocalorie IT per hour per square meter per celsius equals 1.163 W/(m²·K), and kilocalorie IT per hour per square foot per fahrenheit equals 12.518 W/(m²·K). Converting helps compare calorimetric measurements with engineering heat transfer data.
What's the difference between Btu IT and Btu th for heat transfer coefficient?
Btu IT/(h·ft²·°F) equals 5.67826 W/(m²·K) while Btu th/(h·ft²·°F) equals 5.67447 W/(m²·K) - a 0.067% difference due to different Btu definitions. International Table Btu (1055.06 J) versus thermochemical Btu (1054.35 J) affects conversion precision. Use IT for general engineering and th for thermodynamic applications.
What are typical heat transfer coefficient values for different applications?
Natural convection in air: 5-25 W/(m²·K). Forced air convection: 25-250 W/(m²·K). Water convection: 500-10,000 W/(m²·K). Boiling water: 2,500-35,000 W/(m²·K). Condensing steam: 5,000-100,000 W/(m²·K). Converting to Btu/(h·ft²·°F): multiply by 0.176 for all values.
How is heat transfer coefficient used in heat exchanger design?
Engineers use heat transfer coefficients to calculate overall heat transfer coefficients (U-values) in heat exchangers, evaluate thermal performance, and size equipment. Typical values: 500-10,000 W/(m²·K) for water convection, 5,000-100,000 W/(m²·K) for phase change. Converting units helps compare international heat exchanger specifications and thermal design standards.
How does heat transfer coefficient relate to heat flux?
Heat transfer coefficient (h) relates heat flux (q) to temperature difference (ΔT) through Newton's law of cooling: q = h × ΔT. Higher heat transfer coefficients produce greater heat flux for the same temperature difference. For example, h = 100 W/(m²·K) with ΔT = 10 K gives q = 1000 W/m².
How to convert between Btu per hour and Btu per second for heat transfer coefficient?
Btu(IT)/(s·ft²·°F) equals 3600 times Btu(IT)/(h·ft²·°F), since 1 hour equals 3600 seconds. For example, 5.67826 Btu/(h·ft²·°F) equals 20428.8 Btu/(s·ft²·°F), both representing 1 W/(m²·K). Converting helps compare heat transfer coefficients across different time scales in process engineering.
How accurate are heat transfer coefficient conversions?
Our converter uses exact mathematical relationships with 10-decimal precision. W/(m²·K) to Btu(IT)/(h·ft²·°F): multiply by 0.176 exactly (divide by 5.67826). Small differences between Btu IT and Btu th (0.067%) ensure precision for scientific and engineering applications in heat exchanger design and thermal analysis.
How does heat transfer coefficient vary with flow conditions?
Heat transfer coefficients increase with flow velocity, turbulence, and fluid thermal properties. Natural convection (5-25 W/(m²·K)) has lower coefficients than forced convection (25-250 W/(m²·K) for air, 500-10,000 W/(m²·K) for water). Converting units helps compare heat transfer performance across different flow regimes and fluids in thermal design.
How is heat transfer coefficient used in building design?
Building engineers use heat transfer coefficients in W/(m²·K) or Btu/(h·ft²·°F) to calculate heat loss through walls, windows, and roofs, size HVAC systems, and evaluate thermal performance. Typical indoor air convection coefficients: 8-12 W/(m²·K) (1.4-2.1 Btu/(h·ft²·°F)). Converting units helps compare international building codes and insulation standards.
Related Unit Converters
Heat Flux Density
Convert heat flux density units
Thermal Conductivity
Convert thermal conductivity
Thermal Resistance
Convert thermal resistance units
Specific Heat Capacity
Convert specific heat units
Heat Density
Convert heat density units
Thermal Expansion
Convert thermal expansion
Power Converter
Convert power and wattage
Temperature Converter
Convert absolute temperatures
Energy Converter
Convert energy units
Pressure Converter
Convert pressure units