A dehumidifier can be an essential tool in the fight against airborne moisture. But don’t believe the manufacturer’s hype: they base their water extraction claims on tests that might as well be conducted in a sauna. The only way you’ll get a good indication of dehumidifier performance at Kiwi winter temperatures is by using our test results.
Types of dehumidifier
Dessicant vs compressor
Most dehumidifiers available here are compressor (refrigerant) models, which use the same tech as a heat pump or fridge. There are increasing numbers of desiccant dehumidifiers available in the market. They blow air through a rotating disk filled with moisture-absorbing material, and perform better in lower temperatures (below 12°C) than compressor models. The downside is this desiccant model costs three times as much to run as its compressor counterparts, though it generates twice as much heat as other models. Our low-temperature performance scores show how a model performs in temperatures below 10°C.
Things to consider
We’ve found you need to spend at least $350 to snag a good dehumidifier. That said, they’re often on sale, especially in the off-season. If your budget is tight, consider a second-hand model. Our reliability survey found dehumidifiers were very reliable appliances – 96% had never needed repair.
Our energy efficiency score indicates how much energy the dehumidifier uses to extract each unit of moisture from the air. Higher scores mean it uses relatively less energy. We also calculate the running cost per year, based on typical use.
Like a thermostat for relative humidity, this allows you to set desired humidity and the dehumidifier will work until the room reaches that level. All our recommended models have digital humidistats.
Allow you to set the times a dehumidifier will switch on and off, giving it a set duty period each day. If you don’t have this function, you can use an inexpensive wall plug timer.
Most dehumidifiers, including all our recommended models, make upwards of 50 decibels (dBA) of noise. That’s enough to be annoying if you’re trying to watch TV or have a kip. For comparison, a reasonably quiet fridge makes about 40dBA. See our ‘quietness’ scores, a model scoring above 70% is quieter than average.
There’s a trade-off between mobility and tank size. Small water-collection tanks make a dehumidifier more compact, lighter and easier to carry around. But if the tank is too small, you’ll have to empty it several times a day. Models with larger tanks won’t need to be emptied as often but can take up more floor area, and a big tank full of water can be difficult to manoeuvre to the emptying point. All dehumidifiers can be plumbed with a hose allowing continuous drainage, a good option in the garage.
Getting the most from your dehumidifier
Dehumidifiers perform best when placed in the centre of a room with doors and windows shut. We advise vacuuming before switching them on, otherwise the filter can clog up quickly.
Every model we recommend has an adjustable humidistat allowing you to choose from a range of humidity levels. Take care though, removing too much water from the air can result in dry skin and itchy eyes. We recommend a humidity level between 30-50%.
In the colder months, use your dehumidifier in combination with a heat pump, woodburner or electric heater.
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