Dehumidifier 101: A Buying Guide

by Christina Cini    

Dehumidifier Buying Guide

Do you need a dehumidifier? Find out by reading our guide on buying a dehumidifier.

Do you need a dehumidifier?

Start by taking a look around your home. The most noticeable symptoms of excessive humidity may include:

  • wet stains on your walls and ceilings,
  • rotting and weakened wood (evident by wood floors or stairs creaking),
  • mould and fungus,
  • condensation on your windows,
  • peeling wallpaper,
  • blistering paint, and
  • a generally musty, stuffy feeling indoors.

Many types of moulds are potentially dangerous and can lead to health problems. Having a dehumidifier in humid climates or spaces can also help relieve respiratory problems or allergies associated with dust mites, fungus, and mould that thrive in excessively moist environments.

In households and commercial settings, dehumidifiers are often placed in areas that experience excessive moisture such as basements, crawl spaces, kitchens, bedrooms, bathrooms, spas or pool rooms, warehouses and workshops.


Different types of dehumidifiers

There are three main types of dehumidifier technology. Choosing the right one is important to ensure you get the best results. This guide to dehumidifier types will explain the different technologies used, their pros and cons, and help you decide which one will be most effective for you.


Electronic / Peltier Dehumidifiers

Electronic dehumidifiers use a Peltier heat pump to generate a cool surface for condensing water vapour from the air. The design is simpler as there are no moving parts, and has the benefit of being very quiet compared to other types of dehumidifiers. However, because of its relatively poor energy efficiency, this design is mainly used for small dehumidifiers such as the Ionmax ION681 Dehumidifier.

Pros: Very quiet, cheap and affordable

Cons: Not energy efficient, low capacity (removes less than 1L of water per day)

Great for: Small areas with mild humidity problems such as hallways, a child’s bedroom,


Compressor / Refrigerant Dehumidifiers

Ionmax ION610 desiccant dehumidifier in a living room

Compressor dehumidifiers work in a very similar way to an air conditioner and a fridge at home. They cool a metal plate on to which moisture from the air condenses. A fan constantly draws the room air through the dehumidifier and over the cool metal plates, constantly condensing moisture in the air, which drips into the dehumidifier’s water tank. The cool dry air is then reheated by passing it over a hot coil and then back into the room.

Compressor dehumidifiers usually come in larger units and are most effective at typical room temperatures. Although they can remove large volumes of moisture from the air, they consume a fair bit of power and can be quite noisy. They also usually need maintenance every 2 years to refill the gas in the dehumidifier.

Pros: Highly effective at typical room temperatures, can remove large volumes of moisture from the air

Cons: Performance declines in cooler conditions, usually heavy and bulky (10kgs and above), can be very noisy, requires maintenance, consumes a lot of power

Great for: Normal living areas of your home


Desiccant Dehumidifiers

Ionmax ION632 desiccant dehumidifier

These use a desiccant (a substance that readily absorbs water) to absorb the moisture in the air. Desiccants such as salt and silica gel are commonly used in dehumidifiers. In a dehumidifier desiccant, a wheel consisting largely of the desiccant turns slowly through the incoming air stream and absorbs moisture. During the rotation cycle a proportion of the wheel is passed through a stream of warm air which “reactivates” the desiccant by driving off the moisture. This condensed water is then collected in the dehumidifier’s collection tank or automatically drained out via a tube from the back of the unit to the outside or via a plug hole.

Unlike compressor types, desiccant types are quieter, more stable across all temperatures and can reduce humidity to much lower levels. They also require no maintenance and are smaller and lighter than compressor types.

Pros: Smaller and lighter than compressor types, quieter, stable across all temperatures, can operate at much lower temperatures than compressors, can reduce humidity to much lower levels

Cons: Can be more expensive

Great for: The whole house, winter, bedrooms, particularly cool areas such as garages and workshops

Desiccant dehumidifiers such as the Ionmax ION632 Dehumidifier and Ionmax ION612 Dehumidifier above are ideal for all uses, in both home and commercial settings.


Tips on Buying a Dehumidifier

Other than finding out the type of dehumidifier that you need, you should also look out for the following specifications when looking at specific models:

  • Daily dehumidifying rate – Determine how efficient you need the dehumidifier to be based on the situation in your home or office. Sometimes, a small unit will suffice for a mild humidity problem or a small area.
  • Water tank capacity and drainage options – For convenience, ensure that the unit has a large water tank capacity (at least 2L) so you don’t end up having to empty it every few hours. Or, ensure it has a continuous drainage option.
  • Extra features – Look for great features such as electronic louvre, electronic control panels, in-built air filters and heaters, silver nano technology filters, and laundry mode.
Other features to take note of before you buy:
  • Power usage
  • Noise level
  • Need for maintenance
  • Brand and reliability
  • Warranty period


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

Christina Cini

Christina is our very skilled Quality Assurance Manager/ Technician. With her background in Mechatronics Engineering, she is able to apply her knowledge in providing a better understanding into our more technical blog posts such as how products work and the best ways to maintain them.