Everything you need to know about buying a dehumidifier

Wet weather has hit New South Wales hard over the last week and it doesn't look like it's going away anytime soon.

With warm weather in between the torrential downpours there's also plenty of humidity, and a lot of houses right now have that generally damp feeling going on — if they haven't been flooded.

On top of that there's the warning that came out recently about the danger of drying your wet washing indoors because it creates the perfect environment for mould to grow.

If you're looking to combat the damp, musty smell, or prevent the spread of mould an option is investing in a dehumidifier — we've broken down what the appliance is and how they work.

Dehumidifier with touch panel in a living room.
A dehumidifier takes moisture out of the air and can prevent mould growing in the home. (Getty Images/iStockphoto)

What is a dehumidifier?

A dehumidifier is an appliance that essentially removes the moisture from the air, helping to prevent mould. It controls the level of moisture in your home and can help rid your home of damp — which can also prevent mould.

Aside from pulling moisture out of the air a dehumidifier can also help control odours, reduce allergens like dust mites, and help you breathe and sleep better.

How does a dehumidifier work?

The way dehumidifiers work is similar to a vacuum but using refrigeration. They suck air in, filter it, cool it down to condense the moisture, then reheat it and push the warmer, dryer air back into the room. While it does warm the air in a room it's not like a heater. The water, which has been drawn out of the air, is released into a holding tank in the machine, and the machine will stop when it needs to be emptied.

They work best in hot, humid conditions as it's easier to cool down warm air, than try and further cool down cool air to pull the water out of it. A dehumidifier also controls the level of moisture in the room, which can help with issues like damp.

Dehumidifier on the windowsill
If you struggle with damp or too much condensation in your home a dehumidifier could help. (Getty Images/iStockphoto)

Dehumidifier vs Air Purifier: What's the difference?

A dehumidifier works by sucking in air to remove the moisture and filtering warm dry air back into the room. An air purifier purifies the air and reduces the concentration of airborne contaminants in the home like dust, pollen, mould, odours and smoke. The air purifier pulls in air that passes through a HEPA (High Efficiency Particulate Air) filter, which traps contaminants before pushing clean air back out.

What to consider when purchasing a dehumidifier

There are several factors you need to think of when purchasing a dehumidifier.

Humidistat: This lets you set a target relative humidity for the room, and depending on your model it will either be a precise number or a basic setting of low, medium or high.

Low temperature effectiveness: While humidity can be a huge factor in why people want a dehumidifier, the cold can also bring a lot of moisture into the home. You do want to look for a model that can perform well at low temperatures if you're looking to combat winter condensation.

Size of the room: As with any appliance, buying the right one for your needs is important and why you need to factor in the size of your room. If you're looking to use a dehumidifier in a bedroom you'll be looking for a smaller model than one you'd need for a large, open living space.

Portability: Consider how much you want to be moving it and if it's going to be possible through wheels or handles because they can be heavy appliances.

Tank: The size of the tank in the appliance should also factor into your decision making. While a smaller tank might be portable and more compact, it may need to be emptied multiple times a day. But while models with bigger tanks won't need to be emptied as often, they will be more bulky.

Dehumidifiers to suit every room in the home
Dehumidifiers range in price from around $200 to over $1000. Pictured Ausclimate Cool/De'Longhi. (Appliances Online/Harvey Norman)

Dehumidifiers to suit every room in the home

Smaller dehumidifiers that suit areas like bedroom or small living areas range in price from around $200 to around $1,000. If you're looking to use the dehumidifier in a large area like a living room or open plan space, opting for one with a larger tank capacity and more high tech features are desirable.

Ionmax Compact Dehumidifier ($179): Ideal for smaller rooms, has a 2.2-litre tank capacity and only weighs 2.6kg. It has an inbuilt humidistat and auto switch off when the tank is full and can be left to automatically regulate the humidity level in your home without monitoring.

Ausclimate Cool Seasons 7L Desiccant Dehumidifier ($449): At the moderate level for price, the features are what make it a good choice. This powerful, lightweight unit removes 10 litres of moisture from air per day, ideal for rooms as large as up to 30 square metres. It also has a laundry mode for economical clothes drying. The downside to this model is the small 2.2-litre tank capacity.

De'Longhi AriaDry 30L Compact Dehumidifier ($499): Again at the mid-range in price this model is a good choice for the family home because of its smart features. Compact in size, it has an extra power function which will remove up to 30 litres of moisture from your home. It also has a laundry mode for drying clothing indoors and a tank capacity of 4.5 litres, and it allows operating at low room temperature down to 2°C.