Dehumidifier vs air purifier: which is right for you?

In the world of air treatment appliances, it’s easy to get lost in translation. Are dehumidifiers and air purifiers one and the same? What about humidifiers? Whether you suffer from allergies or simply want to improve air quality at home, these devices are worth looking into. But if you’re confused about which is best for you, we can help clear the air. Here’s everything you need to know about dehumidifiers vs air purifiers.

Dehumidifier vs air purifier

OK, let’s by start covering what a dehumidifier and air purifier have in common. Well, both are designed to minimise allergens and pollutants in the room, which is particularly important for people who suffer from allergies, asthma or other respiratory conditions. Now, let’s delve into the specifics.

How does a dehumidifier work?

dehumidifier removes excess humidity (moisture) in the air. It works much like an air conditioner. It uses a fan to draw air over cooled coils, which condenses the moisture in the air, before passing it over warm coils and blowing back ‘dry air’ into your living space. This helps reduce the build-up of airborne mould, dust mites and other allergenic organisms, but doesn’t kill germs.

How does an air purifier work?

An air purifier circulates air through HEPA (High Efficiency Particulate Air) filters, to remove up to 99.97% of common pollutants like dust, mould, pollen, odours, smoke etc. While common filters only remove large airborne particles, purifiers can eliminate smaller ones, too. Air purifiers do nothing to reduce humidity in the air.

Dehumidifier vs humidifier

Ok, dehumidifiers remove moisture from the air. Well, a humidifier does the opposite and adds moisture to the air in your home. It works by emitting water vapor or steam into the air to increase moisture levels. Most air conditioners are equipped with some type of central humidifier designed to humidify the whole house.

Dehumidifier vs Humidifier

Dehumidifier vs air purifier: specs

Dehumidifier Air purifier Humidifier
Function Function Function
Removes excess moisture in the air to combat mould and dust mites Improves the overall air quality in your home by eliminating up to 99.97% of microscopic pollutants in the air Helps improve skin and respiratory health by maintaining sufficient levels of moisture in the air
Ideal for Ideal for Ideal for
Those who regularly dry clothes indoors

People who live in tropical climate areas

If your home smells musty or feels damp

Pet owners

Allergy and asthma sufferers

People who live in homes with carpets and curtains, which carry excessive dust, pollen, and other allergens

Those who live in draught-prone and dry areas and in winter when humidity levels are low inside the home

People who suffer from excessively dry skin, dry nasal passages or congestion

Capacity Capacity Capacity
600ml – 20L 40m² – 200m² 600ml – 6.5L
Cost Cost Cost
$60 – $500* $150 – $1,200* $50- $300*

What are the different types of dehumidifiers?

Dehumidifiers are categorised based on the technology they use to extract moisture from the air. There are three main types:

  1. Compressor dehumidifiers (also called refrigerants) use refrigerated coils to remove excess moisture in the air by way of condensation, before warming it back up and releasing ‘dry air’ into the room. This is considered the preferred option if the temperate in your home typically exceeds 20°C.
  2. Desiccant dehumidifiers use a desiccant material to adsorb moisture from the air in a similar way to silica gel. A fan draws that air through a rotating wheel to dry it, before releasing it. These are generally quieter and more compact in design.
  3. Thermo-electric dehumidifiers use a thermo-electric effect to convert electricity into a temperature difference across a Peltier module, to condensate moisture by way of blowing the warm air on a cool surface. These units suit smaller spaces and work best in warmer climates.

Check out our ratings on dehumidifiers to get an idea of what might be the best option for you.

What size dehumidifier do I need?

room guide for dehumidifier

Best dehumidifiers to buy

  • AROVEC Portable Mini Dehumidifier: $62*
  • Kogan Mini Dehumidifier 2L: $199.99*
  • Breville Smart Dry Dehumidifier: $350*
  • DeLonghi 30L AriaDry Pump Dehumidifier: $599*
  • Ausclimate Cool Seasons Premium 10L Desiccant Dehumidifier: $629*

Air purifier types

What are the different types of air purifiers?

Air purifiers are classified based on the filters they use to clean the air. There are basically four main types.

  1. Standard HEPA air purifiers use a mechanical air filter to trap microscopic contaminants (larger than 0.3 microns), while blowing back clean oxygen into the room. This is the cheapest and most popular option of all.
  2. Ionic air purifiers use an electric field to emit negatively charged ions which attract airborne particles, including allergens, dust and bacteria, which then get trapped on a charged collector plate inside the unit. Just beware that negatively charged ions can generate ozone, so this option isn’t ideal, especially for those who suffer from severe asthma.
  3. Activated carbon air purifiers use carbon that has been treated with oxygen, which effectively absorbs harmful organic molecules and fumes in the air. This is typically the preferred option for pet owners as it helps to dispel odours.
  4. Ultraviolet (UV) air purifiers use a short-wave UV light to ‘blast’ certain micro-organisms and eliminate the potential harm of airborne bacteria and viruses.

Where should I place my air purifier?

where to place air purifier

Best air purifiers to buy

  • Ionmax 2.2L Compact Dehumidifier (Kogan): $119*
  • AROVEC True HEPA Air Purifier (Amazon): $160*
  • Breville LAP300WHT the Smart Air Purifier: $330*
  • Winix Zero 4 Stage Air Purifier: $670*
  • Sharp Air Purifier with Humidifier: $899*

dehumidifier types

Dehumidifier vs air Purifier: important features

Here are the main features to look out for if you’re considering a dehumidifier.

  • Humidistat: Allows you to program your device to keep a room at a desired humidity. Generally, speaking, 30-50% humidity is ideal for human comfort. This feature could show up as a precise number setting, or as a basic low, medium or high setting, depending on the model.
  • Size/tank capacity: It’s important to choose the right size dehumidifier for the room it’s intended for. You need your unit to ‘suck’ enough moisture from the air, without working too hard and wasting energy. Larger rooms like your living room for example, will benefit from a model with a medium to large tank capacity. Larger units typically cost more, but come with added convenience.
  • Drainage: If you don’t want to manually drain your dehumidifier’s bucket, make sure to nab a model that has a drain port to connect a gravity hose to or one with a condensate pump (which is the most effective).
  • Programable timer: Ideally, you want a unit you can program to switch on before you get home and that can turn itself off when you’re out of the house. You could also save some money by turning your dehumidifier on during off-peak electricity times.

If you’re in the market for an air purifier, keep a look out for these features.

  • Change filter indicator: Check that your unit has an indicator to light to signal when your filters need changing, to keep your unit functioning at optimal levels.
  • Smart control: Most air purifiers feature some type of remote control, but some newer models now come with smart connectivity, which allows you to control your device wirelessly from your smartphone or tablet.
  • Eco mode: This is a function that can turn off or keep your unit on standby, when no indoor pollution is detected for 30 minutes. Great energy saver.
  • Quiet operation: Having a powerful unit is ideal, but not if it’s going to keep you up at night. Silence is priceless in the world of appliances!

Dehumidifier vs air purifier: which is more energy efficient?

All things considered, both appliances will set you back about the same amount in energy costs. A standard dehumidifier or air purifier should cost you about 12c-15c per hour to run, depending on your unit’s wattage and electricity usage rate. In layman’s terms, that’s a little less than a microwave.

Dehumidifier vs air purifier: which do you need?

This will ultimately depend on your living conditions, where you live in Australia, whether you have pets, if you have any allergies or asthma, and on a variety of other factors. Here’s a quick recap.

You may benefit from a dehumidifier if:

  • Your home has poor ventilation or water damage or stains on walls or ceilings
  • Your home has a musty or mildew smell
  • You live in humid/hot sticky climates
  • You see mould or small black spots growing in high-humidity rooms (i.e. bathrooms, laundry)
  • You want to manage moisture in bathrooms

You could use an air purifier if:

  • You have allergies, asthma or other respiratory issues
  • You want to reduce pet dander or odours in your home
  • You’re a smoker, to reduce ash and cigarette smoke
  • You live in a home with carpets which can carry excess dust and other allergens
  • You live in an old home which may contain asbestos particles

Dehumidifier vs air conditioner

Modern air conditioning units have built-in filters and fans which perform similar functions to dehumidifiers and air purifiers, with the addition of cooling and/or warming your home for optimum comfort.

Compare Air Conditioners

Picture credits: Canva, Bokeh Stock/, Theskaman306/, Yuttana Jaowattana/

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