# Conduction of heat from metal to air

A typical example is a iron chair gets cold in winters and wooden chain not. We all know iron is more conductive but how this thing possible at molecular level of conduction of heat from metal to air. In general conduction I know it is possible due to vibration transfer of molecules but how it's possible from metal to air. Please explain at molecular level.

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A typical example is a iron chair gets cold in winters and wooden chain not.
not so.

Can you refine your question or provide the source you found this?

PS: If you put a whole bunch of different things at room temperature in a cold refrigerator, do you think any will be colder than any other after sufficient time has passed? Some may get colder faster or slower due to conduction, convection [or radiation] but all will end up at the ambient temperature of the refrigerator, right?

not so.

Can you refine your question or provide the source you found this?

PS: If you put a whole bunch of different things at room temperature in a cold refrigerator, do you think any will be colder than any other after sufficient time has passed? Some may get colder faster or slower due to conduction, convection [or radiation] but all will end up at the ambient temperature of the refrigerator, right?
Okay I am taking about rate of flow of heat. And it's in time limit like we put chairs from indoor to outside for five minutes. That's what I talking about why metal gets cold faster with only contact with air.

Hi,
Conduction electrons.....loosely bound electrons.....same reason as some materials are insulators [wood] others are conductors [iron] of electricity...
those with loosely bound electrons can diffuse more quickly carrying either heat energy of electrical energy or both from atom to atom....

A few views:
Electrical conductivity of non-metals is determined by the susceptibility of electrons to excitation from the valence band to conduction band.....https://en.wikipedia.org/wiki/Valence_and_conduction_bands

https://en.wikipedia.org/wiki/Heat_transfer#Conduction
[has a link to more details]

http://farside.ph.utexas.edu/teaching/sm1/lectures/node86.html

russ_watters
Mentor
You are probably mistaking your perception of the metal chair being cold for the reality of what temperature it really is. Metal chairs both hold and transfer heat faster than wooden ones, which have a lot of air in them, which insulates them. So a metal one will transfer heat from you faster than a wooden one and because our perceptions of "cold" and "hot" are largely based on heat transfer rate, the metal chair will feel colder even if it is not.

CWatters and PietKuip
Hi,
Conduction electrons.....loosely bound electrons.....same reason as some materials are insulators [wood] others are conductors [iron] of electricity...
those with loosely bound electrons can diffuse more quickly carrying either heat energy of electrical energy or both from atom to atom....

A few views:
Electrical conductivity of non-metals is determined by the susceptibility of electrons to excitation from the valence band to conduction band.....https://en.wikipedia.org/wiki/Valence_and_conduction_bands

https://en.wikipedia.org/wiki/Heat_transfer#Conduction
[has a link to more details]

http://farside.ph.utexas.edu/teaching/sm1/lectures/node86.html
I know about general conduction but I am talking of process of transfer of heat from metal to air. How it happens at molecular level or it's just not conduction and is radiation.

Svein
I know about general conduction but I am talking of process of transfer of heat from metal to air. How it happens at molecular level or it's just not conduction and is radiation.
The heat transfer from <something> to air is effected through convection and radiation. However, the internal transfer of heat through a metal chair is largely due to conduction, which is much faster. Therefore, a metal chair is going to be cold all the way through faster than a wooden chair (since wood is a very bad heat conductor).

When you are thinking about heat exchange due to radiation, you are thinking about significant temperature differences. In other words, any substance has to be pretty hot to lose much heat energy via radiation....an incandescent light bulb for example is pretty hot, 2,000 or more Kelvin I think. Since it's encased in a vacuum, virtually all the heat loss is radiation....and something like 97 or 98% of the power is dissipated that way. The largely infrared radiation heats the bulb of course, so it loses heat via conduction as air passes.

See the chart here and the explanation beneath:

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When you are thinking about heat exchange due to radiation, you are thinking about significant temperature differences. In other words, any substance has to be pretty hot to lose much heat energy via radiation....an incandescent light bulb for example is pretty hot, 2,000 or more Kelvin I think. Since it's encased in a vacuum, virtually all the heat loss is radiation....and something like 97 or 98% of the power is dissipated that way. The largely infrared radiation heats the bulb of course, so it loses heat via conduction as air passes.

See the chart here and the explanation beneath: