# Vacuum Temperature Transfer

1. Dec 14, 2005

### quasi426

If something, an object at temperature T, is inside of a vacuum container, can you get that object to change its temperature by placing the container in say a hotter or colder environment. If so, how does the heat transfer?

2. Dec 14, 2005

### Integral

Staff Emeritus
If you place an object inside of a vacuum chamber it will stabilize at the same temperature as the walls of the vacuum chamber. Change the wall temperature and the object will follow. This is an example of radiation heat transfer. There are 3 main heat transfer mechanisms, radiation (this is how we receive energy from the sun); convection, how rooms are heated; and conduction, how heat is transfered from a pan to boil water.

3. Dec 15, 2005

### vaishakh

Conduction can also happen from the surfaces of the conr=tainer to the object-integral.

4. Dec 15, 2005

### Danger

That's true if the object is in fact touching the inner chamber wall, and there is contact between the inner and outer chambers. A Thermos bottle, you'll note, is designed to minimize the contact area between the two shells. In the case of something suspended by an thread in a vacuum chamber, there'd be virtually no conduction.

5. Dec 24, 2005

### skywolf

it depends danger, if im not mistaken heat transfers with that log formula, what i mean to say is that if the heat difference between the hanging object and the wall is very different, then the transfer would be quick

6. Dec 24, 2005

### rachmaninoff

That's why cryogenic dewars have polished, silvered walls: they reflect IR and so reduce radiative heat transfer.

edit: I don't think it's "logarithmic", for radiative heat transfer I believe it goes as to $$T^4$$.

Last edited by a moderator: Dec 24, 2005