heat conduction

[kobi]

how come some saucepans have metal handles that dont get hot?

[ChuckFickens]

Could be several reasons.

Different metals have different rates of conduction, so a handle made of brass or aluminium would get very hot, stainless steel not so hot because it has a much lower thermal conductivity.

You also find most metal saucepan handles are hollow so they have a high surface area, this means they will radiate the heat transferred into them quickly, if the heat can be radiated quicker then they conduct the heat into them they won't get hot.

Also a lot of saucepans will have a small insulating pad between the body of the saucepan and the handle.

[kobi]

great answer! thanks chuck :@)

[beso]

Hollow stainless steel handles that have minimal contact area with the pan conduct very little heat.

It is not so much about the large surface area for radiation as the inside of the handles does not radiate heat way because it faces back on itself. The most important aspect is that hollow handles have very little cross section to conduct the heat.

However a small gap at the bottom of the handle allows air to convect through the inside of the handle and does remove some heat.

[beso]

Actually now I think about it more the opening at the bottom of the handle would be likely to convect heat into the handle as it is exposed to the hot air coming up from the heat source.

Mostly it is about minimal cross section and contact with the pan.

[pcbpage]

A hollow metal handle has a very high surface area per unit mass compared with a solid handle and so will lose its heat through radiation more effectively