On 12 Nov 2008 18:03:00 -0500, Marc Auslander
wrote:

Common knowledge is that we should top up our fuel tank for the winter
sleep. Argument is that otherwise the temp changes will continuously
condense water into the tank, as moist air is pulled in, condensed,
and then expelled.

I have no doubt that the effect is real, but wonder how big it
actually is. How much water per gallon (or liter) of air would
condense in one cycle of some plausible temperature range and some
plausible outside dew point?

(I think I know how to calculate this, but wonder if its already been done?)

Google groups is getting worse for finding stuff..

"
On Fri, 28 Mar 2008 18:08:53 -0400, "Roger Long"
wrote:

OK, worst case, 100% humidity at 80 F., and it all condenses out into the
tank. What volume of water are we talking about for each cubic foot of air?

1 cubic foot = 0.028 316 846 592 000 066 cubic meter
http://www.onlineconversion.com/volume.htm
80 degree Fahrenheit = 26.6666667 degree Celsius
http://www.onlineconversion.com/temperature.htm
At sea level and at 20 °C, dry air has a density of approximately 1.2
kg/m3
http://en.wikipedia.org/wiki/Density_of_air
approx 20g h2o / kg air
http://en.wikipedia.org/wiki/Humidity

0.028 x 1.2 x 20 = 0.672 grams/ccs/ml of water.

"