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11 values, each with its units, its uncertainty, and where it came from.

Material Properties 11

Thermal Conductivity of Copper measured

kCu=401 W/(m⋅K)k_{\mathrm{Cu}} = 401\ \text{W/(m}{\cdot}\text{K)}

W/(m·K)Thermal conductivity of pure annealed copper at 25 °C, about 401 W/(m·K) — the benchmark for practical heat-transfer materials.

Thermal Conductivity of Aluminium measured

kAl=237 W/(m⋅K)k_{\mathrm{Al}} = 237\ \text{W/(m}{\cdot}\text{K)}

W/(m·K)Thermal conductivity of pure aluminium at 25 °C, about 237 W/(m·K); alloy 6061-T6 is markedly lower at roughly 167 W/(m·K).

Thermal Conductivity of Carbon Steel measured

ksteel=50 W/(m⋅K)k_{\mathrm{steel}} = 50\ \text{W/(m}{\cdot}\text{K)}

W/(m·K)Thermal conductivity of plain carbon steel near room temperature, roughly 50 W/(m·K) — about an eighth of copper's value.

Thermal Conductivity of Type 304 Stainless Steel measured

kSS304=16.2 W/(m⋅K)k_{\mathrm{SS304}} = 16.2\ \text{W/(m}{\cdot}\text{K)}

W/(m·K)Thermal conductivity of Type 304 austenitic stainless steel at 20 °C, about 16 W/(m·K) — roughly a third of carbon steel's.

Thermal Conductivity of Water measured

kw=0.598 W/(m⋅K)k_{w} = 0.598\ \text{W/(m}{\cdot}\text{K)}

W/(m·K)Thermal conductivity of liquid water at 20 °C and 1 atm, about 0.60 W/(m·K) — high for a liquid, still 700× worse than copper.

Thermal Conductivity of Air measured

kair=0.0257 W/(m⋅K)k_{\mathrm{air}} = 0.0257\ \text{W/(m}{\cdot}\text{K)}

W/(m·K)Thermal conductivity of dry air at 20 °C and 1 atm, about 0.026 W/(m·K) — the benchmark every insulation is measured against.

Thermal Conductivity of Concrete measured

kc=1.7 W/(m⋅K)k_{c} = 1.7\ \text{W/(m}{\cdot}\text{K)}

W/(m·K)Thermal conductivity of normal-weight structural concrete, roughly 1.4–2.0 W/(m·K) depending on aggregate and moisture content.

Specific Heat of Carbon Steel measured

csteel=486 J/(kg⋅K)c_{\mathrm{steel}} = 486\ \text{J/(kg}{\cdot}\text{K)}

J/(kg·K)Specific heat of plain carbon steel near room temperature, about 486 J/(kg·K) or 0.116 BTU/(lb·°F), rising with temperature.

Emissivity of Polished Aluminium measured

εAl=0.05 —\varepsilon_{\mathrm{Al}} = 0.05\ \text{—}

—Total hemispherical emissivity of bright polished aluminium near room temperature, about 0.05 — an excellent radiant barrier.

Emissivity of Oxidised Steel measured

εsteel=0.8 —\varepsilon_{\mathrm{steel}} = 0.8\ \text{—}

—Total emissivity of oxidised or mill-scaled carbon steel, about 0.8 — against roughly 0.1 for the same steel polished bright.

Emissivity of Flat Black Paint measured

εblack=0.96 —\varepsilon_{\mathrm{black}} = 0.96\ \text{—}

—Total hemispherical emissivity of flat black paint near room temperature, about 0.96 — the practical stand-in for a black body.