How Does a Dehumidifier Work?
How Does a Dehumidifier Work?

Humidity refers to the measure of the amount of water vapor present in the air, depending on the temperature and pressure of the system of interest. The higher the temperature, the more water vapor the air can hold. It indicates the likelihood for precipitation, dew, or fog to be present. And the reason why we never give it a moment's thought is basically because it's invisible! However, high humidity is one of the major reasons for uncomfortable indoor environments. This is why most businesses invest in dehumidifiers to keep the indoor environment comfortable and avoid other structural damages that are caused due to high humidity levels. In this article, we will discuss how a dehumidifier works and how you can choose one for your commercial facility.
Where Does Indoor Humidity Come From?
There are several sources of humidity when it comes to the indoor environment. First and foremost is from nature itself. Then, it can be linked to several daily routine activities that we perform, such as drying laundry inside, cooking without proper ventilation, bathing, washing dishes, and some heating appliances, including unvented natural gas, which also increases the indoor moisture.
Why Does Indoor Humidity Matter?
High humidity can be linked to all kinds of problems, from moldy clothing in the cupboards to rusting appliances. This is the reason why things like cameras and binoculars are sold with water-absorbing sachets of silica gel. But, above all this, high humidity levels are not suitable for your health too. As per a scientific review by Arundel et al, high indoor humidity levels can encourage a flourishing of bacteria, viruses, mites, and fungi, and more respiratory infections and illnesses.
What Are Dehumidifiers?
Dehumidifiers are more or less like vacuum cleaners: they suck in air from one end, take the moisture out of it, and then blow it back out into the room again. The water(moisture) is collected into a tank that needs to be emptied from time to time. But, how is the moisture removed? That's what we will discuss shortly.
Types of Dehumidifiers And How Do They Operate?
There are mainly two main types of dehumidifiers, and each one of them has a different method of collecting moisture. Keep reading to find out their differences to decide which one would be the best fit for your needs.
1. Refrigerant Dehumidifiers
These types of units use the same process as a fridge at home. They use the refrigeration process to cool down a metal plate on which a fan constantly draws the room air through the dehumidifier to condense the moisture from the air. Then the moisture drips into the water tank.
These dehumidifiers are a good choice for rooms with normal temperatures but if you live in an area where the room temperature is 65°F/18°C or lower, these might not be very effective. The reason for this is the fact that they start forming ice on the metal cooling plates. Although this can be resolved by installing high performing components, that eventually adds up to the cost, making them very expensive.
Desiccant Dehumidifiers
These dehumidifiers absorb water from the air using a desiccant, which is a material that absorbs water and is also labeled as "silica gel" that can often be found in cameras, computers or some other product's packaging. The unit has a wheel in front of the incoming air stream that consists of desiccant to absorb moisture.
During the rotation cycle, a proportion of the wheel is passing through a stream of warm air which "reactivates" the desiccant by driving off the moisture and collects the condensed water in the tank or drains it out through a tube at the back.
This type of dehumidifiers are usually smaller and lighter than the refrigerant type and are good for rooms that have much lower temperatures, such as garages and workshops. However, they consume a lot of energy.
How Do You Compare Dehumidifiers?
There are two key measurements you can use to compare different dehumidifiers:
Water removed per day
As the name suggests, you measure how many liters of water a dehumidifier removes in 24 hours of continuous operation. Bigger the machine, the more the water will be removed.
Efficiency
Another key factor that needs to be taken into consideration before investing in a dehumidifier is the amount of energy a machine is consuming. This is calculated by dividing the amount of water removed (in liters) by the power consumed in kilowatt hours.
We hope this article was helpful and provided value. If you understand why having a dehumidifier is essential for your facility, you are indeed looking for one. But with a lot of dehumidifiers available in the market, finding the one that fits your needs could be a daunting process. Check our online HVAC store to find dehumidifiers from different brands and capacities, all on one website with easy navigation and a hassle-free experience. Or you can also call us at (877) 776-8228 to speak with one of our HVAC experts and discuss which unit would be best for you.