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Not by much. Thermal conductivity in gases happens by molecules gaining thermal energy and moving to a colder place. Adding more molecules gives you more energy carriers, but they can’t move as far before bumping in to each other. So the thermal conductivity of most gases increases only slightly with pressure.

If you get near the boiling point, or the pressure is so low the molecules fly the length of your chamber without bumping into anything, the situation is different.

https://www.electronics-cooling.com/1998/09/the-thermal-conductivity-of-gases/

https://www.engineeringtoolbox.com/amp/air-properties-viscosity-conductivity-heat-capacity-d_1509.html

https://www.engineeringtoolbox.com/amp/methane-thermal-conductivity-temperature-pressure-d_2021.html

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Well, gas has a hard time sitting still to "conduct" heat - convection and advection is inevitable.

And you have to be additionally precise in your setup.

More pressure means more gas matter or less gas volume, or somewhere in between.

But take it to its logical extremes: Almost 0 matter means a vacuum and not heat transfer from "conduction," and infinite pressure means infinite matter needs to be heated up, thus no "conduction."

But if convection is permitted, then generally higher pressure makes it easier to transfer heat between molecules

And an extra note to point out that gas cannot actually possess either. 0 pressure means no gas and gases tend to become liquid under sufficient pressure, and in the scenario of gas in the sun, something much more interesting happens.

But each time they bump into each other they bounce apart with shared energy. So the energy is still conducted but not by the original molecule which began with it.

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Ok, thank you

That makes sense. Thanks

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