5 ms·

Admittedly, my understanding of thermodynamics has not progressed much beyond the 2nd grade level (aside from a class on PDEs giving me at least some enhanced i

Admittedly, my understanding of thermodynamics has not progressed much beyond the 2nd grade level (aside from a class on PDEs giving me at least some enhanced intuition). My takeaway from the PDE class was that anything beyond a simple textbook problem needs to be simulated and/or observed experimentally, rather than solved for analytically. But other things being equal, wouldn’t cold air permeate a less dense barrier (say a layer of insulation in a home) more easily than a dense barrier? Just as water (or cold air) would permeate soil more readily than rock.

gvjddbnvdrbv 6y ago
Cold AIR permeates. That is correct. But there is no physical concept of COLD. The physical concept that exists is heat energy. Temperature is defined as the amount of heat energy per unit of matter. When something gets colder the physical process happening is that heat energy is leaving the thing and being transferred somewhere else/being converted to another form of energy. So when cold air comes into a house heat energy is transferred from e.g. the material that makes up the wall into the air warming the air and cooling the walls. The cold air is replacing warm air which moves out of the building.