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The Differences Between Evaporation & Condensation

Water can exist in three distinct phases: solid, liquid and gas. Evaporation and condensation are the terms applied to two of the phase changes of water. Evaporation is the process by which water changes from a liquid to a gas while condensation occurs when water changes from a gas to a liquid. These changes occur continuously in nature and manifest themselves as humidity and dew. Several factors affect both condensation and evaporation.

Temperature
- Warmer temperatures cause increased evaporation. Heat from the sun increases the water temperature near the surface, which causes the water molecules to speed up and gain the energy they need to break the hydrogen bonds with other water molecules and vaporize. Condensation occurs when the air is saturated with water vapor. At higher temperatures, the air can hold more water vapor, so less condensation occurs. However, when the temperature drops, such as overnight, the air can no longer hold as much water vapor and condensation occurs.
Humidity
- Humidity is a measure of how much water vapor is present in the air. Higher percentages of humidity mean more water is present in the air. The rate of evaporation slows down as humidity increases because the air cannot hold much more water vapor. High humidity indoors or out leads to increased condensation; moreover, water vapor changes back into liquid water in an attempt to maintain equilibrium. You can see this type of condensation on windows in humid weather.
Wind
- Increased wind speeds speed up the rate of evaporation. This phenomenon occurs because the wind carries away air that has been saturated with water vapor allowing unsaturated air to move in and take up more water vapor. Higher wind speeds increase evaporation to a certain point beyond which evaporation will continue at a steady rate, but will not increase. Condensation, on the other hand, is not really affected by the wind.
Surface Area
- The surface area of a body of water directly affects the rate of evaporation of that body of water. Larger surface areas mean sunlight can warm a larger area of water, contributing to a higher rate of evaporation. Winds sweeping over the body of water also sweep more saturated air away, further increasing evaporation rates. Surface area affects condensation as well, but it's not the surface area of the body of water that is important here. Water vapor needs a solid surface on which to condense. Surfaces that are cooler than the surrounding air tend to see the most condensation.

Nature