Solar Wind Energy Tower Inc. (fka SWET)

[dog turd cannon]

Thank you for actually offering numbers.

90 degrees @ 15% has 0.0045 lbs of water vapor per 1 lb of air.
60 degress @ 100% has 0.0100 lbs of water vapor per 1 lb of air.

So 0.0055 lbs of water displayed a proportional weight of N2 gas. Evaporation DISPLACES N2.

Molecular weight of H20 is 18 and N2 is 28.

Taking one molecule in per one molecule displayed (rough estimate here if you want the full statistical mechanics answer I can show that as well) the weight of the displayed N2 gas is 0.0055 * 28/18 ~= 0.0085. Honestly, this isn't correct but because the percentage of the gas exchanged here is LESS THAN 1% it is close enough.

So the cooled, humid air is actually lighter than the dry air because the water weight added is 0.0055 and the N2 gas weight displaced is 0.0085.

Get it yet? The cooled air is still LIGHTER than the dry air coming up the tube.

http://www.engineeringtoolbox.com/water-vapor-air-d_854.html

But, we have said this before... CLOUDS ARE COLD and they FLOAT. EVEN WHEN THERE IS SOLID ICE IN THEM.

For those one or two of you that see the little math error in this... I don't feel like working out that little detail since the constituent gas displaces is the same as the mass as a whole. And... it is an order of magnitude smaller error.