Why Is Hot Air Less Dense
At 101.325 kPa (abs) and 15 °C, air has a density of approximately 1.225 kg/m3 (or 0.00237 slug/ft3), about 1/1000 that of water according to ISA (International Standard Atmosphere).

How are hot and cold air different?

Cold air is more dense, therefore it has a higher pressure. Warm air is less dense and has a lower pressure associated with it. Remember, heat is less dense than cold air so the warm air will rise.

Does warm air rise or fall?

Hot air rises because gases expand as they heat up. When air heats up and expands, its density also decreases. The warmer, less dense air effectively floats on top of the colder, denser air below it.

Alexander Ross

Alexander Ross

Gaming, Esports & Interactive Media Writer

Alexander Ross has covered the video game industry for a decade, writing deep dives on game design, esports tournaments, VR developments, and gaming culture.

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