Why does morning dew seem to only soak things that are mostly ‘outdoors’?

804 viewsOtherPlanetary Science

I keep a motorcycle outdoors under a waterproof cover, but noticed that with morning dew the bike is still noticeablely wet on the inside of the cover.

Meanwhile a buddy has his bike in a plywood shed that is by no means air tight but has 4 walls and a roof, but no insulation or air handling fans/AC and he says dew is never an issue..what’s the difference?

In: Planetary Science

14 Answers

Anonymous 0 Comments

Thermal mass, heat conductivity and blocking air flow.

Dew happens when an object gets cold enough to be below the dew point.

The bigger an object, the more thermal energy it has and the longer it will take to cool down. It takes a while for an object like a motorcycle to get cold. A plastic cover does not add much to that thermal mass. A shed has a bigger thermal mass and takes a while to cool down.

Heat conducts through some materials faster than others. Metal is a good heat conductor and will heat up or cool down quickly, wood is a poor heat conductor (called an insulator) – one side can be hot and the other cool for hours.

Finally is airflow. Air moves a lot of heat into and out of an area. While not perfectly air-tight, blocking most airflow can slow heat transfer a lot.

You are viewing 1 out of 14 answers, click here to view all answers.