Humidity and Dehumidification

Dehumidification is the process of getting rid of water vapour in the air. This can be done in 3 ways: Cooling or vapor condensation, Adsorption of water vapor and Absorption of water vapor. Dehumidifiers can help accomplish this task.  

Humidity is the amount of water vapour present in the air. It is a combination of air and water vapor. There are 3 types of humidity, Absolute, Relative and Specific. Absolute humidity is the mass of water in the unit volume of air. Relative humidity is the most common type and is felt almost all over the world. It is the amount of water vapor in the air at a specific temperature. Specific humidity is the ratio of water vapor to dry air in a specific mass.

Cooling the air or vapor condensation can be achieved by using a portable air conditioner , a cooling fan or a fan coil unit; these things reduce the humidity by cooling the air. When the air is cooled below dew point, some of the moisture in the air is condensed and is then drained out. Adsorption of water vapor is when an adsorbent material is used to absorb moisture in the air and lessens humidity. Silica gel packs are an example of adsorbent material used for this method. Activated alumina is another adsorbent material, it is 90% aluminium oxide and is very porous, and it can absorb 60% of its own mass. Absorption is a process in which humidity is reduced using absorbent materials such as a calcium chloride solution.