Originally Posted by Brent Swain
When the outside air is 95% humidity ,changing one batch of wet air for another doesn't dry anything out. The bilge will be near 100% humidity, period, any time there is any water in it.. What causes condensation is a more than 2 degree difference in temperature between the air and a surface. Carpet reduces this difference by keeping the warm cabin air from contacting the hull plate, thus keep the air in the bilge cooler..
I'm not following your point about changing wet air for another. What suggested as much? I was suggesting that carpet would insulate the bilge and not allow for the air to warm and be less than fully saturated.
Your 2 degree example is not quite right, but I think I know what you meant. If air is 100% saturated (ie 100% humidity) than any reduction in temperature is going to cause water to condensate out. Surfaces themselves don't matter. A cold surface causes the boundary air around it to drop in temperature and the moisture condensates out of it.
So that said, I didn't really follow the reply. When you can warm air, it will hold more moisture and/or be less saturated with the same amount and be further from the dew point and less likely to condensate.