thumb|right|Condensation forming in the low pressure zone above the wing of an aircraft during landing due to [[adiabatic process|adiabatic expansion]]
Condensation is the change of the state of matter from the gas phase into the liquid phase, and is the reverse of vaporization. The word most often refers to the water cycle. It can also be defined as the change in the state of water vapor to liquid water when in contact with a liquid or solid surface or cloud condensation nuclei within the atmosphere. When the transition happens from the gaseous phase into the solid phase directly, the change is called deposition. Condensation is usually associated with water.
Initiation
Condensation is initiated by the formation of atomic/molecular clusters of that species within its gaseous volume—like rain drop or snow flake formation within clouds—or at the contact between such gaseous phase and a liquid or solid surface. In clouds, this can be catalyzed by water-nucleating proteins, produced by atmospheric microbes, which are capable of binding gaseous or liquid water molecules.
Reversibility scenarios
A few distinct reversibility scenarios emerge here with respect to the nature of the surface.
- absorption into the surface of a liquid (either of the same substance or one of its solvents)—is reversible as evaporation.
It is also a crucial process in forming particle tracks in a cloud chamber. In this case, ions produced by an incident particle act as nucleation centers for the condensation of the vapor producing the visible "cloud" trails.
Commercial applications of condensation, by consumers as well as industry, include power generation, water desalination, thermal management, refrigeration, and air conditioning.
Biological adaptation
Numerous living beings use water made accessible by condensation. A few examples of these are the Australian thorny devil, the darkling beetles of the Namibian coast, and the coast redwoods of the West Coast of the United States.
Condensation in building construction
right|thumb|Condensation on a window during a rain shower.
Condensation in building construction is an unwanted phenomenon as it may cause dampness, mold health issues, wood rot, corrosion, weakening of mortar and masonry walls, and energy penalties due to increased heat transfer. To alleviate these issues, the indoor air humidity needs to be lowered, or air ventilation in the building needs to be improved. This can be done in a number of ways, for example opening windows, turning on extractor fans, using dehumidifiers, drying clothes outside and covering pots and pans whilst cooking. Air conditioning or ventilation systems can be installed that help remove moisture from the air, and move air throughout a building. The amount of water vapor that can be stored in the air can be increased simply by increasing the temperature.
Table
See also
- Air well (condenser)
- Bose–Einstein condensate
- Cloud physics
- Condenser (heat transfer)
- DNA condensation
- Dropwise condensation
- Groasis Waterboxx
- Kelvin equation
- Liquefaction of gases
- Phase diagram
- Phase transition
- Retrograde condensation
- Surface condenser