A dehumidifier earns its place in an Australian house for two jobs: drying washing indoors through a wet winter, and keeping a damp room below the humidity where mould grows. Between 40 and 60 percent suits most houses; above 60 is where mould and dust mites get comfortable.
The number that matters is extraction in litres a day, and it is measured under laboratory conditions that no bathroom matches. Treat it as a ranking rather than a promise. Tank size matters almost as much, because a machine pulling 20 litres a day into a 5-litre tank needs emptying more than once unless you run the drain hose.
1. Best overall: De'Longhi 21L Tasciugo Aria Dry
21 litres a day for rooms up to 90 cubic metres, with four-stage filtration including a HEPA-type element and activated carbon, a laundry function, Real Feel control that manages humidity and temperature together, Wi-Fi and a 12-hour timer. 490 watts, 13.5kg on castors, continuous drain hose in the box. Two-year warranty. Owners rate it 4.5 at The Good Guys.
The filtration is what separates it: carbon is what takes the musty smell out of a damp room rather than just the moisture.
What We Like:
- Four-stage filtration including carbon
- 21L a day with an anti-frost device
- Two-year warranty
What We Don't Like:
- 5L tank fills quickly at full extraction
2. Best value: De'Longhi 25L Tasciugo AriaDry Multi
More extraction than the 21L model for less money: 25 litres a day, rooms to 100 cubic metres, three fan speeds, laundry mode, Wi-Fi and a 47-decibel maximum. Owners rate it 4.8 at The Good Guys.
The trade is filtration and warranty. It carries a dust and BioSilver filter rather than the carbon stack, and one year instead of two.
What We Like:
- 25L a day, the most here per dollar
- Covers 100m³
- 47dBA maximum
What We Don't Like:
- One-year warranty, and no carbon filter
3. Best humidity control: Breville the Smart Dry Plus
Set a humidity anywhere between 30 and 80 percent in five-point steps and the Sensair system holds it. Rooms to 50 square metres, a 3.5-litre tank, two automatic fan speeds, laundry mode, a timer, and Wi-Fi with Alexa and Google. 350 watts, the lowest draw of the larger machines. Two-year warranty. Owners rate it 4.5 at The Good Guys.
Breville does not publish a daily extraction figure for this model, which makes it hard to compare directly against the De'Longhis on the number that matters most in a wet room.
What We Like:
- Humidity set point in 5% steps
- 350W
- Live humidity display
What We Don't Like:
- No published extraction rate
4. Best for a small room: De'Longhi 16L Tasciugo AriaDry Multi
16 litres a day for rooms to 75 cubic metres, at 285 watts and 40 decibels, which is the quietest and the least power-hungry machine here. Dust, BioSilver and anti-allergy filters, laundry function, two fan speeds, 12-hour timer. 12.3kg. Owners rate it 4.6 at The Good Guys.
The 2.1-litre tank is the smallest here, so the drain hose is close to compulsory for continuous use.
What We Like:
- 40dBA and 285W
- Anti-allergy filter
- Lightest of the De'Longhis
What We Don't Like:
- 2.1L tank
5. Best cheap option: Breville the Smart Dry
10 litres a day for rooms to 30 square metres, a 2.5-litre tank, laundry mode, humidity control from 30 to 80 percent in five-point steps, Bluetooth and Wi-Fi, and a pre-filter plus carbon filter for dust, pet dander and odours. 350 watts, 9.5kg. Owners rate it 4.6 at The Good Guys.
10 litres a day is half what the bigger machines manage, so it suits a bedroom or a wardrobe wall rather than a whole laundry.
What We Like:
- Cheapest here
- Carbon filter for odours
- 9.5kg
What We Don't Like:
- 10L a day limits it to one room
6. Best 2-in-1: Breville Smart Dry 2-in-1 Viral Protect
25 litres a day plus an AntiViral HEPA-13 filter, so it works as an air purifier when the dehumidifier is not needed. Rooms to 60 square metres, a 6.5-litre tank, auto or continuous modes, purify-only mode, 24-hour timer, defrost function and a filter reset alert. Two-year warranty. Owners rate it 4.7 at The Good Guys.
It is the most expensive machine here, and the HEPA filter is a consumable at four to six months.
What We Like:
- 25L a day plus HEPA-13 purification
- 6.5L tank, the largest here
- Purify-only mode
What We Don't Like:
- Filter needs replacing every four to six months
How to choose a dehumidifier
| Extraction | Tank | Room | Power | Warranty | Price | |
|---|---|---|---|---|---|---|
| Breville Smart Dry | 10L/day | 2.5L | 30m² | 350W | — | $350–400 |
| De'Longhi 16L | 16L/day | 2.1L | 75m³ | 285W | 1 year | $450–500 |
| De'Longhi 21L | 21L/day | 5L | 90m³ | 490W | 2 years | $600–700 |
| De'Longhi 25L | 25L/day | 5L | 100m³ | 490W | 1 year | $500–600 |
| Breville Smart Dry Plus | Not published | 3.5L | 50m² | 350W | 2 years | $600–700 |
| Breville 2-in-1 Viral Protect | 25L/day | 6.5L | 60m² | 420W | 2 years | $700–800 |
The two brands do not quote room size the same way: De'Longhi uses cubic metres and Breville square metres, so those columns are not directly comparable.
Extraction figures are laboratory numbers. They are measured at around 30°C and 80% humidity, which is warmer and wetter than an Australian laundry in July. Real output in a cool room is a fraction of the rating, which is why the anti-frost device on the De'Longhi 21L matters.
Run the drain hose if the machine works all day. Every model here ships with one. Without it the tank fills and the machine stops, usually overnight.
A dehumidifier warms the room slightly. The compressor's waste heat goes into the space, which raises the temperature a degree or two. In winter that is a small bonus.
For mould, aim below 60 percent. That is the threshold where mould and dust mites stop thriving. A machine that holds a set percentage does this more reliably than one you switch on and off.
FAQs
Dehumidifier or a heater for drying washing?
The dehumidifier, comfortably. It removes the water from the air rather than heating the room, and at 285 to 490 watts it draws a fifth of what a 2400-watt heater does.
Will one help with asthma?
Controlling humidity reduces dust mites and mould, which are common triggers. The filtration is a secondary benefit, and none of these replaces a purifier with a sealed HEPA filter except the 2-in-1.
How often do the filters need cleaning?
The dust pre-filters on all of them are washable and want rinsing monthly in constant use. The 2-in-1's HEPA element is a replacement part at four to six months.
Do they work in a cold room?
Less well, and they can ice up. Refrigerant dehumidifiers lose efficiency as air gets colder, which is what the De'Longhi 21L's electronic anti-frost device is for.
