The dehumidifier is used to lower the moisture content of air inside a room or any other closed space. In many applications, like operation theatres and recording rooms, the low humidity level attained by air-conditioners may not be sufficient; in such cases a dehumidifier is used.
Dehumidifiers are highly useful in extremely humid and cold atmosphere like places where there is heavy rainfall. In such places almost everything, like bed sheets, books, etc. tends to get wet. Electrical and electronic appliances get easily damaged in such conditions. Air-conditioners cannot be used in such situations because the temperature is already too low, and the best alternative is the dehumidifier. Dehumidifiers are portable units and can be easily moved from one room to the other.
Dehumidifiers are small packaged devices that run on the principle of refrigeration. They have all the components that a typical refrigerator or air-conditioner has, but the cycle is used in a different manner. The dehumidifier has one fan instead of the two available in the air-conditioner.
The fan draws room air through the cooling coil. In this process the temperature of the air becomes less than its dew point temperature, and the moisture gets removed. This air is then passed over the condenser where its temperature becomes high, and it gets further dehumidified. This air is supplied in the room and circulated continuously through the dehumidifier, thus decreasing the overall humidity inside the room. The air filter is mounted near the cooling coil so that the filtered air is delivered into the room.
Dew collected from the air is collected in a small storage tank located at the bottom of the dehumidifier. When the tank gets filled the dehumidifier gets tripped and will restart only after emptying the tank.
Operation of the dehumidifier can be controlled by the humidistat mounted in the room. The humidistat is the devise that measures relative humidity inside the room. When the value of the relative humidity reaches a certain level, it can be configured to start the dehumidifier. The humidistat works like the thermostat in a room air-conditioner.
The capacity of a humidifier is specified in terms of the amount of moisture it can remove from the air under certain specified entering air conditions into the cooling coil. A higher capacity dehumidifier can remove more amounts of moisture from the air per hour.
Dehumidifiers are manufactured by number of a companies. One of the most popular dehumidifiers is from GE Company. It’s a small, cute unit white in color. It has wheels in its bottom part, which makes it easy to move from one place to the other.