Thermal Conductivity Converter
Convert thermal conductivity between units instantly. Includes conversion tables, common equivalents, and calculation formulas.
Formula
Converted Value = Input Value x (From Factor / To Factor)
Thermal conductivity conversion uses W/(m*K) as the base unit. Key factors: 1 BTU/(h*ft*F) = 1.730735 W/(m*K), 1 cal/(s*cm*C) = 418.68 W/(m*K). The conversion combines energy, length, and temperature unit changes. R-value (insulation rating) is inversely proportional to thermal conductivity.
Worked Examples
Example 1: Building Insulation Specification
Problem: Fiberglass insulation has k = 0.04 W/(m*K). Convert to BTU*in/(h*ft2*F) and calculate R-value per inch.
Solution: To BTU*in/(h*ft2*F): 0.04 / 0.1442279 = 0.2773\nR-value per inch = 1 / (conductance per inch)\nR per inch = 0.0254 m / (0.04 W/(m*K)) = 0.635 m2*K/W\nConvert to imperial: 0.635 / 0.17611 = 3.60 ft2*F*h/BTU per inch
Result: k = 0.04 W/(m*K) = 0.277 BTU*in/(h*ft2*F), R-3.6 per inch
Example 2: Heat Sink Material Comparison
Problem: Compare copper (401 W/(m*K)) and aluminum (237 W/(m*K)) in BTU/(h*ft*F).
Solution: Copper: 401 / 1.730735 = 231.7 BTU/(h*ft*F)\nAluminum: 237 / 1.730735 = 136.9 BTU/(h*ft*F)\nRatio: 401/237 = 1.69, so copper conducts heat 69% better
Result: Copper: 231.7, Aluminum: 136.9 BTU/(h*ft*F)
Frequently Asked Questions
What is thermal conductivity?
Thermal conductivity (k or lambda) measures how well a material conducts heat. It is defined as the rate of heat transfer through a unit thickness of material per unit area per unit temperature difference. The SI unit is W/(m*K). High values (like copper at 401 W/(m*K)) mean the material conducts heat efficiently, while low values (like air at 0.026 W/(m*K)) indicate good insulation properties.
What is the relationship between thermal conductivity and R-value?
R-value (thermal resistance) is the inverse of thermal conductance. For a material of thickness L and thermal conductivity k, the R-value equals L/k. Lower thermal conductivity means higher R-value (better insulation). In US customary units, R-value is in ft2*F*h/BTU. Fiberglass insulation has low k (0.04 W/(m*K)) giving high R-value, while metals have high k giving negligible R-value for the same thickness.
Why do metals have high thermal conductivity?
Metals have high thermal conductivity because their free electrons can rapidly transfer kinetic energy through the material. In metallic bonding, outer electrons are delocalized and move freely through the crystal lattice. These electrons carry thermal energy much faster than the lattice vibrations (phonons) that dominate heat transfer in non-metals. This is why copper and aluminum are preferred for heat sinks and cooking pans.
Is Thermal Conductivity Converter free to use?
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