Back Ford
page 5
CDA logo
Copper in health
Metal Thermal conductivity
copper 394
silver 418
aluminium 238
stainless steel 13
Table 2. Thermal conductivity.
When you heat one side of a material, the other side will warm up. The values above are a measure of how quickly the other side gets as hot as the heated side.
Thermal conductor
Copper is a good conductor of heat. This means that if you heat one end of a piece of copper, the other end will quickly reach the same temperature. Most metals are pretty good conductors; however, apart from silver, copper is the best.

It is used in many heating applications because it doesn't corrode and has a high melting point. The only other material that has similar resistance to corrosion is stainless steel. However, its thermal conductivity is 30 times worse than copper's.

Photo of car radiator parts
Picture 4. Car radiator and cooling system made of copper and brass.
Copper allows heat to pass through it quickly. It is therefore used in many applications where quick heat transfer is important. These include
Device Uses
Copper plate Saucepan bottoms.
Copper pipes Heat exchangers in hot water tanks, under floor heating systems, all weather football pitches and car radiators.
Heat sinks Computers, disk drives, TV sets.

Part of interactive graphic of thermal conduction
Part of interactive graphic of thermal conduction
Picture 5 How copper conducts.
Conducting heat
Copper is made from a lattice of ions with free electron (see page 4). The ions are vibrating and the electrons can move through the copper (rather like a gas).

In picture 5, the left hand end of the piece of copper is hotter. The copper ions at the hot end vibrate more. [Note the electrons have been left out of the picture to keep it clear].

Let's look at just a few electrons and see how they conduct heat from the left to the right.

  1. A free electron collides with an ion at the hot end, and gains kinetic energy (it speeds up).
  2. It moves to the cold end.
  3. It collides with a 'cold ion', making the previously cold ion vibrate more. This heats up the cold end.

In this way, energy is transferred through copper, from hot to cold.

Interactive graphic of thermal conduction
Picture 6. A cool lattice. If we heat the left hand end, then the energy will be carried along by conduction.
Non-metals conducting heat
Compare this with how heat is conducted in a non metal. The vibrating particles pass on the vibrations to their nearest neighbours. This is much slower. That's why metals are the best conductors - their free electrons can carry the energy along their length.

back top next
Question 4
Most metals are conductors of heat. Most non-metals are good . This is because metals rely on free to transfer energy from a hot place to a cold place. Solid non-metals rely on the of particles which are held together by bonds.