What air is heavier: warm wet air or cold dry air?

Answer 1

Moist air is less dense than dry air. Warm air is less dense than cold air. Therefore, warm wet air is less dense than cold dry air, making the cold dry air heavier.

Answer 2

cold air

So why does cold air fall? That is simple: it is heavier than warm air. And why is it heavier? That is slightly less simple, but only slightly. As with any gas, the air (a generic term for the mixture of the gasses in our atmosphere), contains molecules that move (or agitate). This movement (or agitation) is greater as the temperature rises. The molecules move in ever greater orbits, taking up more space. This causes the mass of the air to expand. Although the total mass of a lump of air has not changed, the mass is more spread out and so any given cubic area of it will be lighter. An analogy is found with popcorn. A half pound of popcorn before being popped may fit into a cup. After popping, the same corn would fill a large saucepan. Its total weight will be more or less the same half pound that it always was, but if you filled up the original cup with the popped corn, it would weigh less than the unpopped corn as the rest of it would no longer fit into the cup. Expanding hot air is similar. A cup of cold air would weigh more than a cup of hot air.

Answer 3

Cold dry air is heavier that cold wet air at the same temperature because H2O vapor is lighter than air (2+16 for H20, 32 for O2, 28 for N2. Warm air is lighter than cold air.
We feel warm wet air as heavy because it interferes with our ability to sweat and keep cool.

Answer 4

Warm air can dissolve more water particles than cold water. Since water weighs more than air, warm wet air is much heavier than cold air (humid air 'feels' much heavier in the lungs even!).

Answer 5

Hot air rises and cold air falls.

Answer 6

depends on temperature , humidity and other options