Or does it lose heat?
What are other ways to prevent heat loss?
For a science project I have to create a thermos and I found some insulation foam, would this work?
Any other ideas?
Insulation merely slows down the transfer of heat from one side to the other, it does not stop it.
A thermos is actually a dewar bottle in which there are essentially two bottles, one inside the other with a vacuum between them. The surfaces facing the vacuum are also mirrored. this stops heat three ways. it stops it by conduction (the only conduction path is through the bottle neck where the two bottles touch each other.) because a vacuum cannot conduct heat. It also stops it by convection because again there is nothing in the vacuum to convect, and it also prevents heat flow through radiation by mirroring the inner surfaces of the bottles so that radiant heat is reflected back to it’s source instead of being allowed to be absorbed by the contents of the thermos.
Dewars are very efficient at slowing heat flow but they are not perfect. there is still some conduction through the neck of the bottle. That is why, at least small ones that are not highly stressed, are generally made of glass which is a poor conductor of heat. there is also conduction through the stopper of the bottle.
4 responses to Does insulation foam prevent heat loss?
A true thermos has a vacuum between the inner and outer containers.
But foam insulation is a very good insulator.
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not at all
uhh, well if it didn’t prevent heat loss/gain, then it wouldn’t be called INSULATION foam.
Insulation merely slows down the transfer of heat from one side to the other, it does not stop it.
A thermos is actually a dewar bottle in which there are essentially two bottles, one inside the other with a vacuum between them. The surfaces facing the vacuum are also mirrored. this stops heat three ways. it stops it by conduction (the only conduction path is through the bottle neck where the two bottles touch each other.) because a vacuum cannot conduct heat. It also stops it by convection because again there is nothing in the vacuum to convect, and it also prevents heat flow through radiation by mirroring the inner surfaces of the bottles so that radiant heat is reflected back to it’s source instead of being allowed to be absorbed by the contents of the thermos.
Dewars are very efficient at slowing heat flow but they are not perfect. there is still some conduction through the neck of the bottle. That is why, at least small ones that are not highly stressed, are generally made of glass which is a poor conductor of heat. there is also conduction through the stopper of the bottle.
Does insulation foam prevent heat loss?
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