The science behind humidifiers and dehumidifiers

Dehumidifiers and humidifiers are essential tools in controlling humidity in your home. Understanding how these machines work can help you make informed decisions when it comes to humidity levels in your home.

How humidifiers and dehumidifiers work

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Have you ever wondered how to achieve the perfect level of humidity in living spaces? Whether for battling excessive moisture to soothing dry air, Ionmax humidifiers and dehumidifiers are used for a variety of purposes, from keeping a stable humidity level to preventing moulds from growing.

It is also used to combat rising respiratory and other health problems due to frequent exposure to dry air, especially during the winter months. Humidifiers are slowly becoming more common, as the market size of humidifiers is anticipated to grow by 6% between 2021 and 2027.

Understanding humidity

Before diving into how these small devices work, let's first grasp the concept of humidity. Humidity refers to the amount of moisture present in the air. It can greatly increase our comfort, health and overall conditions of our surroundings. High humidity levels can result in damp environments, encouraging the growth of mould, mildew and other harmful microorganisms.

If your household is experiencing these issues, a dehumidifier is an effective way to manage them. If a dehumidifier is unavailable, you can learn how to reduce humidity levels without a dehumidifier in our blog post.

Relative humidity levels that are too low (30% and below) can cause cracking wooden furniture, dry eyes, throat, and nasal passages and also chapped lips and cracked skin.

Humidifiers can also help to soothe issues by adding more moisture in the air, giving you better indoor air quality.

The following factors are what affect humidity levels.

Factors affecting humidity levels

Ambient humidity depends on a number of factors that are specific to the environment and location. Common factors include

  • Temperature - warm air can hold more moisture than cold air, which means that as temperatures increase, the air’s capacity to hold water vapour also increases, which means higher humidity levels. With that being said, places that warmer climates tend to be more humid than their colder counterparts.
  • Ventilation - the exchange of outdoor and indoor air through ventilation systems or openings within the room like doors and windows, affect humidity. Outdoor air can bring varying levels of moisture, which can increase or decrease indoor humidity levels.
  • Proximity to water sources - living near large bodies of water like oceans, rivers, or even lakes can increase humidity levels as these areas tend to have higher humidity due to evaporation. It’s also worth noting that leaving bathroom doors open after showers or leaving water leaks unfixed can also affect humidity levels.
  • Occupancy and activities - the number of people in a space and their activities can impact humidity. People exhale moisture into the air when they breathe, which will, in turn, raise humidity levels.

How do they work?

Compressor and desiccant dehumidifiers are two of the most common dehumidifier types used in Australia and globally. Both dehumidifier types have their own respective benefits. Compressor dehumidifiers are most efficient in warmer climates across Australia, whereby their desiccant counterparts are able to function throughout the year, adapting to all climates.

The Ionmax ION90 humidifier, on the other hand, utilise ultrasonic technology to treat the air to your fancy. Below is an explanation of how these everyday air treatment appliances work.

Desiccant Dehumidifiers

Desiccant dehumidifiers work by using a large desiccant rotor to absorb moisture from the processed air stream.

The wheel works somewhat like a sponge, which is used to soak up excess moisture from the air passing through it. Some dehumidifiers use silica gel to capture water molecules by the process of absorption, whereas Ionmax dehumidifiers are equipped with self-regenerating zeolite technology to absorb excess moisture.

How desiccant dehumidifiers work

Compressor Dehumidifiers:

The compressor dehumidifier consists of several components:

  1. Fan - the process where the fan draws in warm and humid air from the environment around and aims it towards the dehumidifier.
  2. Refrigerant - compressor dehumidifiers have a refrigerant, usually with a low boiling point.
  3. Compressor - the compressor is an important component of the dehumidifier used for compressing refrigerant gas, which increases its temperature and pressure. This compression creates heat energy, which would be released later in the cycle.
  4. Condenser coil - the compressed refrigerant flows into a condenser coil, a series of heat-exchanging tubes located outside the dehumidifier. The refrigerant releases its heat energy into the environment which allows it to condense into a liquid state.
  5. Expansion valve - liquid refrigerant passes through an expansion valve where its pressure is reduced, causing it to evaporate and turn back into a gas.
  6. Evaporator coil - the evaporated refrigerant flows through the evaporator coil, which is kept cool. The refrigerant absorbs heat in the air, which causes the moisture to condense and form water droplets.
  7. Reservoir - condensed water droplets are collected in a reservoir
  8. Reheating - The compressor reheats the air before releasing it into the room, restoring it to a comfortable temperature.

Ultrasonic humidifiers

The Ionmax ION90 humidifier uses ultrasonic technology to help increase humidity levels in the air using a plate known as an ultrasonic transducer that is found on the bottom of the water tank.

Through the use of high -frequency sound waves, the transducer will create vibrations in the water that break down the water into small, microscopic droplets that will turn into fine mist, which will then be released into the air as cool or warm mist.

The Ionmax ION90 humidifier also includes a humidistat, so users can set a desired humidity level while monitoring the current ambient humidity in the room.

Best practices

To get the most out of your dehumidifier or humidifier, follow these tips:


  1. Proper placement - adhere to the manufacturer's instructions of where to place your dehumidifier. Ionmac recommends placing your unit at a safe distance from walls or furniture. For best results, place it in a central location, like a hallway.
  2. Regular maintenance - although Ionmax desiccant dehumidifiers utilise self-regenerating zeolite technology, it’s still important to vacuum the unit’s filter to ensure that large dust particles do not end up making their way into the unit.
  3. Determine desired humidity level - Ionmax dehumidifiers allow you to select your preferred level of humidity for best results. The ideal relative humidity level for homes is between 30 to 60%.


  1. Proper placement - just like dehumidifiers, humidifiers also need to be placed ideally to avoid any damage to the surroundings. Ensure that there are no obstructions above the unit, as the vapour emitted might damage clothes, furniture and other objects above them.
  2. Use distilled or filtered water - to minimise mineral buildup, use filtered water in your humidifier. This helps reduce the release of minerals into the air and keeps the humidifier clean. The ION90 contains a nanotechnology demineralisation filter to help with this issue.
  3. Clean and refill regularly - follow manufacturer instructions for cleaning and refiling your unit’s water tank. This will help prevent the growth of bacteria and mould, ensuring clean, healthy moisture is released into the air.

In a nutshell

Dehumidifiers and humidifiers are essential tools to create a stable indoor environment. By understanding the science behind how they work, we see how these devices effectively regulate humidity levels and aid with our well-being. Whether it's removing excess moisture or adding moisture to the air, dehumidifiers and humidifiers are adaptable devices that help create a comfortable and healthy living space.

Browse through Ionmax’s wide range of humidifiers and dehumidifiers to find the perfect unit to suit your needs. Ionmax also has a wide range of air purifiers within our catalogue to cater to all your air treatment needs.

Written by Aidan Liew

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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