How Does A Dehumidifier Work?

September 12 2019

How Does A Dehumidifier Work?
How Does A Dehumidifier Work?

How Does A Dehumidifier Work?


You might not realise it but our homes can be a breeding ground for a whole bunch of complications because there are high levels of moisture and humid air. Find out whether a dehumidifier will solve the problem, how a dehumidifier works and how to make the most of it in the home.

Dehumidifiers are designed to keep homes humidity levels in check, so the air is more comfortable and there are fewer signs of unhealthy air quality like condensation, damp and mould problems.

What Is Humidity?

A lot of the time we don’t give a thought to the atmosphere in our homes. (Well, it is invisible.) But what a lot of us don’t realise is that there’s water in the air all around us in the form of a gas called water vapour. From showering, cooking and even breathing, normal household activities without proper ventilation can cause the humidity levels in a home to be surprisingly high. Defined by the amount of water vapour in the air, humidity greatly influences the comfort we experience in a home.

But don’t panic, it is completely normal to expect some rooms to have higher humidity than other rooms. For example, when cooking, the kitchen is going to be higher than a bedroom because there is moisture being released from boiling pans, breathing and running hot water.

Keep Humidity Below 50 Percent

The most comfortable indoor humidity level will vary from one household to the next, depending on personal preferences; humidity in the home should ideally be between 30 and 50 percent.

How Does A Dehumidifier Work?

The two primary types of dehumidifiers on the market today are compressor dehumidifiers (sometimes known as refrigerant dehumidifiers) and desiccant dehumidifiers. Each of these primary types of dehumidifier has unique attributes that make them suitable for different applications.

How Does A Compressor Dehumidifier Work?

A compressor dehumidifier (sometimes known as a refrigerant dehumidifier) removes water through producing a cold surface that the moisture can condense on.

Similar to how a fridge does, a compressor dehumidifier uses a fan to pull warm, moist air from the home that passes through a filter and then over a series of coils – a refrigerated coil and a heated coil. Using condensation on cold refrigerant coils to remove moisture, the warm, moist air condenses into water droplets and drips into the water container inside the machine. The dried air is then reheated via a heated coil and released back into the home as drier air free from moisture.

A compressor dehumidifier is the most common dehumidifier found in a home because they provide the ideal level of water extraction at the lowest cost operating effectively at varying temperatures.  Prices for a compressor dehumidifier range from £30 – £350 but in general, the higher the price, the higher the extraction rate. As is often the case, spending more up front often means a saving in the long run.

All dehumidifiers available on RIBI.MT are compressor (refrigerant) dehumidifiers. Ebac dehumidifiers with Advanced Patented Smart Control are perfect for all homes and can save £50 to £150 on running costs per annum compared to a desiccant dehumidifier.


How Does A Desiccant Dehumidifier Work?

A desiccant dehumidifier removes water through natural absorption using a heater to regenerate the air.

In a desiccant dehumidifier, moisture is removed from humid air through the process of absorption. Instead of using condensation on refrigerant coils to remove moisture from the air, desiccant dehumidifiers use a chemical called desiccant – hence the name – to soak up moisture in the air.

This kind of dehumidifier retails for between £20 and £250 and is the most comparable to a compressor dehumidifier in terms of extraction and size. That being said, desiccant dehumidifiers are more expensive to run and their high extraction rate is often misused.

Ebac Recommend

John Elliott MBE DL, Ebac Chairman said, “We do not recommend desiccant dehumidifiers for the home because of their running costs, compressor dehumidifiers will solve the problem and are much cheaper to run”.

Find out more about compressor dehumidifiers and desiccant dehumidifiers here.

When Should I Use A Dehumidifier?

Household Activities

Like we have seen, breathing, cooking, drying laundry, ironing and showering all release moisture and cause surprisingly high humidity. Without proper ventilation excess moisture can lead to condensation, damp or mould that can, over time, lead to health and structural problems.

Condensation, Damp or Mould

Homes that suffer from frequent condensation, damp or mould means there is a unnecessary high level of humidity. Using a dehumidifier reduces and restores a homes humidity so the air is more comfortable and there are less signs of unhealthy air quality.


Those suffering from allergies, asthma or the common cold can benefit from a dehumidifier. A dehumidified room makes the environment less hospitable to allergens such as dust mites, mould and other irritants that thrive and multiply in humidity.

Using Your Dehumidifier

Figuring out how to use a dehumidifier can seem overwhelming, but it doesn’t have to be. To get the best from a dehumidifier it is important to understand the 3 main considerations – where will the dehumidifier be used, how much water needs to be removed and how to control the dehumidifier.

Where Will the Dehumidifier Be Used?

Most domestic dehumidifiers are used to prevent and solve condensation, damp or mould in an occupied home. And although these issues may only be a problem in one part of the house, the source of excess moisture will come from number of places. Most people place the dehumidifier in the room where the problem is, however there are models available that monitor the entire home and can be placed wherever as long as there’s clearance for air to flow in and out and plugged into an electrical outlet like Ebac’s Smart Control.

How Much Water Needs to Be Removed?

Dehumidifiers have different extraction rates that are difficult to understand but as a general rule, the main factor determining what extraction needed is the more people in the home, the more excess moisture needs to be removed.

Ebac dehumidifiers have been designed to work for the UK climate. What this means is that other dehumidifier brands litre rating refer to tropical climates not found in UK conditions. In the UK a dehumidifier needs to removed around 1 – 3 litres every day to solve condensation, damp or mould problems around the home so a dehumidifier with an extraction rate of 12 – 20 litres will be more than sufficient.

How to Control the Dehumidifier

Most dehumidifiers available today have an automatic humidistat that monitors the moisture in the air so it can turn on and off to maintain the humidity level selected. Ebac’s Smart Control takes readings of the relative humidity every hour of the day and stores this in its memory learning a homes daily routine. Depending on a persons needs, it is likely many will be wasting electricity and even money because you cannot dehumidify below 40% which is why dehumidifiers with Ebac’Smart Control will minimise running costs by automatically detecting when to operate.


Click here for Ebac 3850 21 Litre Smart Dehumidifier

Click here for Ebac 2650 18 Litre Smart Dehumidifier


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