How compressor dehumidifiers work

Compressor dehumidifiers are the legacy dehumidifiers that have been used since the 1960s. Here's how they dehumidify the air through condensation.

How compressor dehumidifiers remove moisture from the air

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Compressor dehumidifiers and desiccant dehumidifiers are the two most commonly used dehumidifiers in Australia. While desiccant dehumidifiers are rather new, compressor dehumidifiers have been used for decades since the early 1960s. They are known for being efficient in removing moisture from the air in warmer climates and for their low energy consumption.

Structure of a compressor dehumidifier

A compressor dehumidifier generally consists of a compressor, a long metal tube that coils up in the evaporator section and the condenser section, a fan, and a water tank. There is refrigerant flowing through the metal tube to cool down the tube at the evaporator section and to warm up the tube at the condenser section.

Refrigerants used in a dehumidifier

The first generation of refrigerants used were chlorofluorocarbons (CFCs), also known as greenhouse gases. These days, a safer and more environmental friendly option known as Hydrofluorocarbons (HFCs) is used instead.

Dehumidifying mechanism of a compressor dehumidifier

Humid air passes through the evaporator where moisture in the air condenses and drips into the water tank. This cold dry air is then passed through the condenser to return to room temperature.

Illustration of how compressor dehumidifiers work


  1. Humid air in the indoor environment is drawn into the compressor dehumidifier and passed through the evaporator.
  2. The moisture in the air touches the cold surface of the evaporator, causing it to condense into water and drip into the water tank. As a result, moisture is removed from the air.
  3. The cold dry air is then passed through the condenser which has a warm surface, warming it up before it is blown back into the indoor environment.

The cooling and warming processes within the dehumidifier

One of the main functions of the compressor is to evaporate and condense the refrigerant through pressure in order to create cold and warm surfaces respectively.

  1. The refrigerant is sucked into the compressor from the evaporator section where a low-pressure environment occurs, causing it to vapourise and absorb heat in the process. This creates a cold surface along the metal tube in the evaporator section of the dehumidifier.
  2. The refrigerant is then pushed out into the condenser section of the dehumidifier where a high-pressure environment occurs, causing it to condense and release heat in the process. This creates a warm surface along the metal tube in the condenser section of the dehumidifier.


As a temperature difference is required for the moisture in the air to condense within the evaporator section of the dehumidifier, compressor dehumidifiers work best in warmer climates. It is important to understand how compressor dehumidifiers work so that you can make better decisions in choosing a suitable dehumidifier for household use.

View our full range of dehumidifiers here or contact us for further information or assistance.

Disclaimer: The information provided in this article is for general reference only. Please seek advice from professionals according to your needs.

Ionmax Australia

Ionmax Australia

Founded in 2003, Ionmax Australia has received numerous awards and accolades for its innovative products and commitment to customer satisfaction. Ionmax dehumidifiers and air purifiers have been recognised for their effectiveness in reducing indoor air pollutants and improving air quality. The company is committed to researching and developing new and improved products that meet the needs and expectations of its customers, making it a trusted name in households across Australia and beyond.

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