Dehumidifiers

Calculating the Right Dehumidifier Capacity for Your Room

Dehumidifier capacity is measured in litres per day, the volume of moisture the unit can extract from the air over 24 hours. A higher litre rating covers larger spaces more effectively. As a general guide:

• Up to 20L/day - suitable for bedrooms, small living areas, and single rooms up to around 30m²

• 20–35L/day - better suited to open-plan living areas, larger rooms, and homes with moderate dampness

• 35L/day and above - appropriate for large homes, basements, or spaces with serious ongoing moisture problems

Ceiling height also matters. Rooms with high ceilings hold more air volume than the floor area alone suggests, so it is worth sizing up if your home has non standard ceiling heights. Knowing your room size before comparing models makes it much easier to narrow down the right unit.

Tank vs Continuous Hose for Dehumidifiers

Most dehumidifiers come with a built-in water collection tank that fills as the unit runs and needs to be manually emptied. Tank sizes typically range from 2 to 6 litres depending on the model, and a larger tank means less frequent emptying, which matters most if the unit runs overnight or while you are away.

Many dehumidifiers include a continuous drain outlet that connects to a standard garden hose, allowing water to drain directly into a sink, floor drain, or outdoors without any manual intervention. This is the most convenient setup for laundries, basements, or any space where the unit runs regularly for extended periods. If continuous drainage is a priority, check that the model you're considering includes the outlet fitting and that there's a suitable drain point nearby.

Energy Consumption and Running Costs

Running costs for a dehumidifier in Australia depend on the unit's wattage, how many hours it operates per day, and your local electricity rate. Most home dehumidifiers draw between 200 and 500 watts. Lower capacity models sit at the cheaper end to run, while larger units pulling more moisture from bigger spaces use more power. Models with a built-in humidistat automatically switch the unit off once the target humidity level is reached, then restart it when moisture rises again. This prevents the unit from running continuously when conditions don't require it. Many units from brands like Breville and DeLonghi include this as standard, which makes a noticeable difference to running costs over time compared to units that run at a fixed rate.

Noise Levels and Sleep Modes on Dehumidifiers

Dehumidifiers produce a low hum during operation from the fan and compressor. Noise levels are measured in decibels (dB). Most home models operate between 35 and 50 dB, with quieter units sitting closer to the lower end of that range. For context, 40 dB is roughly equivalent to a quiet library.

Many dehumidifiers include a sleep or night mode that reduces fan speed and dims indicator lights for quieter overnight operation. Running on a lower fan speed does reduce moisture extraction slightly, but for most bedrooms this trade-off is worthwhile. If the unit will be placed in a bedroom or living area where noise matters, look for models that specify a low dB rating and include a dedicated quiet mode.

Air Purification Features in Hybrid Dehumidifiers

Some dehumidifiers include an integrated air purifier with HEPA or activated carbon filtration, capturing dust, pollen, pet dander, and airborne particles at the same time as managing humidity. These hybrid models are a practical option for households dealing with both dampness and indoor air quality concerns.

Households with allergy sufferers or asthma can benefit from the combined approach, particularly during high pollen periods. For practical advice on managing hay fever symptoms at home, the guide to tips for hay fever season covers air quality management alongside other useful measures. Keep in mind that filter replacements are an ongoing cost with hybrid models, so factor that into the comparison when weighing up price.

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