Humidity is increasing globally and so is the need and the market of dehumidifiers is rising. Along with all other side effects, the worst part of excess humidity is suffocation. This is not the high temperature that bothers you most in the summer, this is humidity. We the human beings are endothermic in nature. We maintain constant internal body temperature and any change in that can be lethal. To maintain that internal temperature in summer, we evaporate what is commonly called as sweating. When the humidity is high, we cannot evaporate enough due to lack of humidity gradient that is required for sweating or evaporation. Well to maintain the humidity up to optimum level, we use dehumidifiers. Now the question is How does a dehumidifier work? How to choose best dehumidifier?
Generally, there are two types of dehumidifiers and they both work differently.
Both these dehumidifiers have different mechanisms of removing the moisture from the air. First, we will see how refrigerant dehumidifiers work.
1.Mechanism of refrigerant dehumidifiers
The basic mechanism of refrigerant dehumidifiers is based on condensation. The name refrigerant has been derived from refrigerators as these dehumidifiers work on the same principle as refrigerators and air conditioners but also there are variations that make dehumidifiers a different product. This whole process is divided into two steps:
The fan in refrigerant dehumidifiers draws in the moist air. The moist air then passed through the cold coils. When hot moist air passes through the cold coils, the air loses its warmness and gets cooler. As the air gets cooler its ability to hold a retain water is reduced and water drips down in the bucket. Have you ever seen a glass full of ice that has drops outside, what do you think is why those drops are there? The same thing happens to that, as the air passes through that cold glass, it gets cooler and cannot hold the moisture anymore. That moisture accumulates in the form of drops outside the glass. Likewise, in dehumidifiers when air goes through the coils, water drops down in the form of drops and it is then accumulated in the bucket.
Heat recovery system
Then air enters the heat recovery system, where it is reheated to regain the original temperature. Finally, another fan sends this dry air back to the room.
2.Mechanism of desiccant dehumidifiers
These dehumidifiers do not work by warming or cooling the air. They are simply based on moisture absorbing material. They have such chemicals in them that can absorb moisture from the air.
This can work in many ways. Simple and smaller dehumidifiers that are designed to cover very small areas (up to 200 square Ft) simply have desiccant material in it and they constantly absorb moisture from the air when air passes through them. They are required to be recharged when they reach their maximum capacity.
While the larger units have wheels in them. Wheels are covered by the desiccant material that can absorb moisture. A fan draws in the moist air, the air passes through the wheel and the absorbent on the wheel absorbs the moisture. Air leaves the unit from the other end. Wheel rotates continuously, when the upper surface that faces the air to absorb the moisture goes down, the absorbing material is recharged/dried/regenerated and it gets ready to absorb more moisture.
Capacity to remove water
A dehumidifier’s size is measured by its capacity to remove water per day. This is usually measured in pints. In general, refrigerant dehumidifiers have comparatively more capacity than desiccant dehumidifiers. The most common capacities are 30pints. 50pints and 70pints.
This capacity must be compatible with the area you want to dehumidify and the conditions of humidity whether it is moderately high or extremely high.