Why isn’t water temperature taken into account when calculating evaporation rate?

196 viewsOtherPhysics

Basically the title. First I look up a calculator, and there were different variables, even the air temperature, but not water. I always thought hotter water means faster evaporation. And if it’s true, how happens that it doesn’t matter when calculating evaporation rate? Is it because evaporation require a lot of heat, and no matter how much heat water have, it’s not enough to affect evaporation rate?

In: Physics

3 Answers

Anonymous 0 Comments

Water has a Heat of Vaporization of ~2260 J/g and a Specific Heat of ~4.2 J/g°C.

That means that heating 1.0 g of water from 5°C to 100°C takes ~400 J but boiling it away takes another ~2260 J.

Although actively boiling water is somewhat different from the processes happening with passive evaporation, the fact that the Heat of Vaporization is so much higher than the Specific Heat will still come into play and mean that corrections for evaporation rate given the exact temperature of the water would be relatively minor changes compared to everything else.

You are viewing 1 out of 3 answers, click here to view all answers.