complete.tools

Heat Transfer Coefficient Converter

Convert heat transfer coefficients between W/(m²·K), BTU/(h·ft²·°F), cal/(s·cm²·°C), kcal/(h·m²·°C) and other units.

What this tool does

Convert heat transfer coefficients between W/(m²·K), BTU/(h·ft²·°F), cal/(s·cm²·°C), kcal/(h·m²·°C) and other units. Type an amount in watts per square meter kelvin, choose the units, and the tool converts it to BTU (International Table) per hour square foot degree Fahrenheit. It offers 7 heat transfer coefficient units and also shows the same amount in the others.

Inputs

  • Value: A number.
  • From: Choose one: Watt per square meter kelvin, Watt per square meter degree Celsius, Kilowatt per square meter kelvin, BTU (International Table) per hour square foot degree Fahrenheit, BTU (thermochemical) per hour square foot degree Fahrenheit, Calorie (thermochemical) per second square centimeter degree Celsius, Kilocalorie (International Table) per hour square meter degree Celsius. Starts as Watt per square meter kelvin.
  • To: Choose one of the same 7 units as "From". Starts as BTU (International Table) per hour square foot degree Fahrenheit.

How to use

  1. Enter the amount you want to convert.
  2. Choose the unit to convert from and the unit to convert to.
  3. Read the result: the converted amount and the same amount in the other units. It appears once every required field has a valid value.

Worked examples

Conversions from watts per square meter kelvin to BTU (International Table) per hour square foot degree Fahrenheit:

  • 1 W/(m²·K) ≈ 0.17611 BTU (IT)/(h·ft²·°F)
  • 5 W/(m²·K) ≈ 0.880551 BTU (IT)/(h·ft²·°F)
  • 10 W/(m²·K) ≈ 1.761102 BTU (IT)/(h·ft²·°F)
  • 50 W/(m²·K) ≈ 8.805509 BTU (IT)/(h·ft²·°F)
  • 100 W/(m²·K) ≈ 17.611018 BTU (IT)/(h·ft²·°F)

Multiply the number of watts per square meter kelvin by about 0.17611 to get BTU (International Table) per hour square foot degree Fahrenheit. The factor follows from exact definitions. It has more digits than fit here, so it is shown rounded.

Sources: Watt per square meter kelvin: SI Brochure, 9th edition (2019). BTU (International Table) per hour square foot degree Fahrenheit: NIST SP 811 (2008), Appendix B.9.

Limitations

  • Converts the unit of a heat transfer coefficient only. It does not work out heat loss, a U-value or an R-value for a wall or a material.
  • Each BTU and calorie definition is labeled. Pick the one your source uses.

FAQs

Q: How do I convert W/(m²·K) to BTU/(h·ft²·°F)?
A: One W/(m²·K) is about 0.1761 BTU (International Table) per hour square foot degree Fahrenheit. Going the other way, one BTU/(h·ft²·°F) is about 5.678 W/(m²·K).
Q: Is W/(m²·K) the same as W/(m²·°C)?
A: Yes. The coefficient is per degree of temperature difference, and a difference of one kelvin is the same as a difference of one degree Celsius.
Q: Which BTU and which calorie does the page use?
A: BTU is the International Table BTU unless the label says thermochemical. Calories per second are thermochemical (41,840 W/(m²·K) each) and kilocalories per hour are International Table (1.163 W/(m²·K) each).

Explore Similar Tools

Explore more tools like this one: