1. What is Thermal Conductivity?

Thermal conductivity is a material property that indicates its ability to conduct heat. It is defined as the quantity of heat transmitted through a unit thickness in a direction normal to a surface of unit area, due to a unit temperature gradient under steady state conditions.

2. How Does the Conversion Work?

The calculator uses the following conversion formula:

Where:

• \( k_{W/mK} \) — Thermal conductivity in Watts per meter-Kelvin
• \( k_{BTU \cdot in/ft^2 \cdot h \cdot °F} \) — Thermal conductivity in BTU-inch per square foot-hour-Fahrenheit
• 0.1442 — Conversion factor between the units

3. Importance of Thermal Conductivity

Details: Thermal conductivity is crucial in material selection for insulation, heat exchangers, and thermal management applications. It helps engineers design efficient thermal systems and select appropriate materials for specific temperature conditions.

4. Using the Calculator

Tips: Enter the thermal conductivity value in BTU·in/ft²·h·°F units. The calculator will automatically convert it to W/mK. The input must be a positive number.

5. Frequently Asked Questions (FAQ)

Q1: Why convert between these units?
A: BTU·in/ft²·h·°F is commonly used in the US, while W/mK is the SI unit used internationally. Conversion is necessary when working with international standards or literature.

Q2: What are typical values for common materials?
A: Copper ≈ 400 W/mK, Aluminum ≈ 200 W/mK, Steel ≈ 50 W/mK, Wood ≈ 0.1 W/mK, Insulation ≈ 0.04 W/mK.

Q3: Is thermal conductivity temperature dependent?
A: Yes, for most materials thermal conductivity varies with temperature, though the calculator assumes room temperature values.

Q4: What's the difference between thermal conductivity and thermal resistance?
A: Thermal resistance (R-value) is thickness divided by thermal conductivity. Higher R-value means better insulation.

Q5: Can this calculator be used for anisotropic materials?
A: No, this assumes isotropic materials where conductivity is the same in all directions.