The Naked Scientists

The Naked Scientists Forum

Author Topic: ?How does the environment effect the melting of ice and how fast will it take?  (Read 3284 times)

Offline tommya300

  • Hero Member
  • *****
  • Posts: 655
    • View Profile
If ice were suspended in the center of an insulated sealed room two times the volume of the ice, where the ice is surrounded by ambient air, and in another similar room, if ice were suspended the same way only that it is surrounded with ambient water, which will melt to a point where the environment were ambient, and how long will it take?

I know that the R value and thickness of the insulation  needs to be known I leave that for you to decide a realistic R value and thickness.
« Last Edit: 20/12/2010 14:44:46 by tommya300 »


 

Offline lightarrow

  • Neilep Level Member
  • ******
  • Posts: 4586
  • Thanked: 7 times
    • View Profile
If ice were suspended in the center of an insulated sealed room two times the volume of the ice, where the ice is surrounded by ambient air,
If there is no exchange of heat with the room's walls, the ice cannot melt, because that mass of air (I assume it's at standard pressure = 1 atm) is not enough to do it.
 

Offline tommya300

  • Hero Member
  • *****
  • Posts: 655
    • View Profile
If ice were suspended in the center of an insulated sealed room two times the volume of the ice, where the ice is surrounded by ambient air,
If there is no exchange of heat with the room's walls, the ice cannot melt, because that mass of air (I assume it's at standard pressure = 1 atm) is not enough to do it.

Under Ideal situation but you are not given an R value nor a thickness of insulation.

The ice will not stay ice forever in the boxed room will it?
 

Offline peppercorn

  • Neilep Level Member
  • ******
  • Posts: 1466
    • View Profile
    • solar
I would guess it would be the water as water has a higher heat transfer coefficient than air. Although the air is more 'free' to convect than water.
 

Offline Geezer

  • Neilep Level Member
  • ******
  • Posts: 8328
  • "Vive la résistance!"
    • View Profile
The water will melt the ice, but if the insulation has an R value of 1,000,000, the resulting cold water will never reach ambient temperature, although it will asymptotically approach it over a very long time.

The air version will get to the same point a bit faster faster because it has less mass.
 

Offline Geezer

  • Neilep Level Member
  • ******
  • Posts: 8328
  • "Vive la résistance!"
    • View Profile
Tommy,

Would you mind if we move this topic to General Science? It's not really a chemistry question.
 

Offline lightarrow

  • Neilep Level Member
  • ******
  • Posts: 4586
  • Thanked: 7 times
    • View Profile
If ice were suspended in the center of an insulated sealed room two times the volume of the ice, where the ice is surrounded by ambient air,
If there is no exchange of heat with the room's walls, the ice cannot melt, because that mass of air (I assume it's at standard pressure = 1 atm) is not enough to do it.

Under Ideal situation but you are not given an R value nor a thickness of insulation.
What is R? The thermic resistance/thermal conductivity? When he wrote "insulated" I assumed he intended "total insulation"; probably I didn't understand well.
 

Offline Geezer

  • Neilep Level Member
  • ******
  • Posts: 8328
  • "Vive la résistance!"
    • View Profile
What is R? The thermic resistance/thermal conductivity? When he wrote "insulated" I assumed he intended "total insulation"; probably I didn't understand well.

You got it. It's a normalized insulation value for building materials in the USA. I don't know if it's used anywhere else. I think the idea is that you can add the R values of all the materials that, for example, make up a wall to determine the wall's total R value. There are probably tables associated with it that allow builders to easily compute the heat gain/loss in different climates.

Like you, I picked an R of one million, which would equate to virtually no loss or gain  :D
 

The Naked Scientists Forum


 

SMF 2.0.10 | SMF © 2015, Simple Machines
SMFAds for Free Forums