Dehumidification

The fundamental principles of dehumidifying - cooling, adsorption or absorption

Sponsored Links

Air may be dehumidified by

  1. Cooling the air - condensation of vapor in the air
  2. Adsorption of water vapor in the air
  3. Absorption of water vapor in the air

1. Cooling the air - vapor condensation

In a cooling system the humidity is reduced by cooling the air below dew point. A part of the moisture in the air is condensed and drained out.

2. Adsorption

In an adsorption system the humidity is reduced with an adsorbent material as silica gel or activated alumina.

Adsorption is a physical process in where moisture is condensed and held on the surface of the material without any change of in the physical or chemical structure of the material. The adsorbent material can be reactivated by heat.

Silica gel - SiO2

Silica gel - SiO2 - is a hard, adsorbent, crystalline substance and very porous. Voids are about 50 - 70% by volume and adsorbs water up to 40% of its own mass. The bulk density of silica gel is 480 - 720 kg/m3. The specific heat capacity is 1.13 kJ/kgK.

Activated alumina

Activated alumina is about 90% aluminum oxide Al2O3 and very porous. Voids are about 50 - 70% by volume and adsorbs water up to 60% of its own mass. The bulk density is 800 - 870 kg/m3. The specific heat capacity is 1.0 kJ/kgK.

3. Absorption

In an absorption system the humidity is reduced with an absorbent material such as a calcium chloride solution. Absorption involves a change in the physical or chemical structure of the material and it is in general not easy to reactivate the material.

Sponsored Links

Related Topics

  • HVAC Systems Heating, Ventilation and Air Conditioning systems ...

Related Documents

Sponsored Links



SketchUp Engineering ToolBox - Online 3D modeling!

SketchUp Engineering ToolBox - enabled for use with the amazing, fun and free Google SketchUp.


Search the ToolBox

Google
Web The Engineering ToolBox

© The Engineering ToolBox 2005

8 5 9


.
Resources, Tools and Basic Information  for Engineering and Design of Technical Applications!

Resources, Tools and Basic Information for Engineering and Design of Technical Applications!

Google
Web The Engineering ToolBox