Home, heating & renovation

Product overview

Welcome to New Zealand’s trusted, independent source of practical consumer information. Join us now to access all our information and Consumer advisers when you need them.  

Dehumidifiers

16jun dehumidifiers hero default

Which dehumidifier is right for your home?

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.

From our test

Join us now for instant access

Join more than 100,000 members today and you'll get:

  • Independent info
  • Thousands of test results and research you can trust
  • Everything in one easy place
  • Expert support a phone call away if things go wrong


Our test

We measure the water each model collected at three combinations of temperature and humidity: 16°C and 65% relative humidity (RH), 12°C and 75% RH, and 8°C and 90% RH. Then we score them on their performance. These scores are weighted to focus on performance between 8°C and 12°C as dehumidifiers often start to struggle at this temperature range.

We also consider running costs, and whether they fill to their claimed capacities before switching off. We finish our test with an assessment of each model’s ease of use, including the usability of controls, ease of cleaning and whether we had any trouble emptying the tank.

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.

Points to consider

Low temperature effectiveness

You can get excessive moisture in the air at high and low temperatures, and will want a machine that can deal with both. However, makers usually give water removal rates at conditions which make their machines look the best, typically 30°C and 80 percent relative humidity (RH).

For example, a machine may claim to remove 16 litres a day at 30°C and 80 percent RH.

The figures sound impressive, but are misleading for anyone wanting to deal with winter condensation, when temperatures get below 15°C. Try asking for figures at 10°C and 15°C, although they will not always be available.

Using a heater and a dehumidifier together will heat a cold and damp room more quickly and cheaply than using just a heater.

Energy efficiency

Removing water from air takes energy. So the more efficient the dehumidifier, the less it costs to run.

But energy efficiency isn’t always the whole story. If the dehumidifier is used in a cold damp room, the heat it releases helps reduce the room’s relative humidity. So in these circumstances, energy efficiency is less important: water removal should be your main consideration.

Mobility

Look for a model with good castors and a handle or hand-grips to ensure easy movement. Models can range in weight from 10 to 25 kilograms. If you have stairs, shop around for a model that’s not too heavy for you. If space is a concern, check the dimensions. Some take up much less space than others.

Tank

There is usually a trade-off between mobility and 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.

Models with a front tank are easier to empty. Check that it is easy to remove, and big enough to hold at least 5 litres of water. Some models have a drain hose adaptor, which removes the water as it’s collected, so it can be poured straight down a drain.

Controls and labels

Make sure they are easy to see, understand and use. An adjustable humidistat allows you to set humidity levels. Rotary dial humidistats with no precise markings make it hard to find the actual humidity level. If this is particularly important (as it may be for some people with allergies, for example) you can buy a humidity gauge to check humidity levels. See www.thermometer.co.nz.

Noise

Many dehumidifiers make upward of 50 decibels (dBA) of noise – enough to be annoying if you’re trying to watch TV, hold a conversation or sleep. (A reasonably quiet fridge makes about 39-40dBA.)

Reliability

We received information on 589 dehumidifiers in our 2017 appliance reliability survey.

To see which brands are trustiest, become a paying Consumer member or log in.

×