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Thermal Conductivity Reference Section: Thermal Conductivities
OK, you all knew that copper was a good conductor, but most people assume that copper is the best conductor of heat. Far from it, in fact! The best conductor of heat, by a massive margin is diamond (although the conductivity varies according to the direction of heat transfer and the quality of the diamond). Silver is also a better conductor than copper, but stainless steel, used for a variety of heat transfer uses (hot water cylinders, heat exchangers etc, is actually a very poor heat transfer material.
On the other end of the scale, you can compare the quality of various insulating materials. One of the best is air, which is odd, given that air is normally the culprit in removing heat from objects you want to keep hot. The reason for that, is that air convects (so does water), and this can massively increase it's potential to receive heat from a hot object.
Material
| Thermal conductivity
W/(m·K) | | Diamond | 900 - 2320 | | Silver | 429 | | Copper | 401 | | Gold | 318 | | Aluminium | 237 | | Lead | 35.3 | | Stainless steel | 12.1 - 45.0 | | Steel | 48 | | Sandstone | 2.4 | | Ice | 2 | | Concrete, stone [2] | 1.7 | | Limestone | 1.53 | | Dense Concrete | 1.44 | | Sand ` | 1.41 | | Brick | 1.15 | | Dry Soil | 1.1 - 1.5 | | Glass | 1.1 | | Thermal Grease | 0.7 - 3.0 | | Damp Soil | 0.7 | | Water | 0.6 | | Wood | 0.04 - 0.4 | | Epoxy | 0.19 - 0.3 | | Cement, portland | 0.29 | | Alcohols and oils | 0.1 - 0.21 | | Rubber | 0.16 | | Thermalite Blocks | 0.14 - 0.19 | | plasterboard | 0.18 | | hardwood | 0.16 | | Softwood/Plywood | 0.138 | | chipboard | 0.108 | | strawbales | 0.09 | | stony soil | 0.052 | | cork | 0.043 | | fibreglass | 0.04 | | flax/sheepwool | 0.037 | | cellulose(recycled paper | 0.035 | | expanded polystyrene | 0.033 | | polyurethane foam | 0.023 | | still air | 0.02 |
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