Submitted by SunCloud-777 t3_zy30z3 in todayilearned
Reply to comment by PeachSnappleOhYeah in TIL Snow is an excellent insulator because it consists of about 90–95 percent trapped air (fresh). This is the reason why igloos are warmer inside than outside, and why some animals in colder regions build snow caves to spend the winter while hibernating. by SunCloud-777
It's wrong to say that water (or ice) is a poor conductor of heat because it takes a lot of energy to melt it. It's correct to say that water has a very high "heat of fusion" (latent heat involved in turning 0-degree ice into 0-degree water). Conductance refers to its ability to carry heat from a hot object on one side of it to a cold object on the other side. Snow (not ice) has very low conductance due to its large air content, the same reason house insulation works well; it has nothing to do with ice's high heat of fusion.
> Conductance refers to its ability to carry heat from a hot object on one side of it to a cold object on the other side
edit:
> It’s wrong to say that water (or ice) is a poor conductor of heat because it takes a lot of energy to melt it.
not what i said.
you basically said i was wrong, and then explained something else, said in other words.
i was trying to keep it simple. sure, it's not 100%. what i said is basically right, i explained in way that's easy to understand. unlike your explanation.
warm air inside the igloo does not conduct heat very well through the igloo material. if water was a better heat conductor, it would melt faster. many of the different thermodynamic properties are related to each other.
The reason it takes a lot of heat to change the temperature of water, or to cause a phase change from solid to liquid, or from liquid to gas, isn't because "water is a poor conductor of heat," but rather because "water has a high specific heat," which is the amount of energy (calories, BTUs, etc) needed to change a given weight of the material (one gram) by a given amount (one degree celsius).
This is what makes water pretty much the "ideal material" to use to transmit power in things like steam engines (turbine steam engines are still heavily used in power generation) or to carry heat in things like engine cooling systems or residential/commercial heating systems.
Water really has quite a few remarkable properties from a scientific or engineering standpoint.
>... you have to put a lot of energy (heat) against it to heat it up (or cool it down)
This refers to specific heat (energy required to change temperature) and is not the same as thermal conductivity.
>Ice wants to stay ice. this is why ice cubes work so well to keep drinks cool.
This refers to heat of fusion. Also not the same as thermal conductivity.
You could replace the ice in snow with different substances with lower specific heat, lower heat of fusion, and a melting point so high that melting is irrelevant, and it would still be a poor heat conductor due to the large air content.
every one of your comments in your comment history is argumentative, about stupid details and generally telling other people they are wrong.
you seem like a genuine asshole.
edit: omg that creep actually replied from an alt account just to get the last word in! hahahahaha
and every one of your replies in this thread is you being an argumentative asshole who also happens to be wrong half the time.
You were wrong though.. you said it was a poor conductor of heat since it takes a lot to heat it up….
Those are different things.
Its heat conductance isn’t amazing, but is not the same or well related to its specific-heat-capacity & the energy it takes to phase change…
None of that has much to do with igloos keeping warm largely by being a windbreaker & containing the air in the space… it anything.. its the conductivity of the air in the space that matters… and not the walls at all.
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