Desiccant models use a disc or belt of moisture-absorbing material to dry the air. Refrigeration models use refrigeration coils, similar to a fridge or air conditioner, to cool the air and condense the moisture out. See our buying guide for more information on these and thermo-electric models.

We recommend dehumidifiers with CHOICE Expert Rating of at least 70%.

The CHOICE Expert Rating score is made up of water removal (30%), claimed water removal (20%), energy efficiency (30%) and ease of use (20%).

We set up our dehumidifiers in a temperature- and humidity-controlled test chamber. For each model, we measure the amount of water removed during three test runs at different temperature/humidity combinations that reflect humid winter climates (between 8°C and 16°C and 65% to 90% relative humidity). For more details, see our article on how we test dehumidifiers.

This is a comparative rating of the model's energy consumption and how much water it extracts. An efficient model will use less energy but extract more water when compared to other models.

Each dehumidifier has a claim as to how much water they can extract during a 24-hour period. We work out whether they meet this claim at three different relative humidities and temperatures. 

Our lab testers assess each model for ease of accessing and emptying the water tank, quality of instructions and labels, using the controls, mobility of the unit and ease of cleaning it.

The heating effect from the dehumidification process (measured at 12C and 75% relative humidity). This is generally noticeable but far short of what a typical 2000W or 2400W heater will deliver. See our buying guide for more about this.

The measured power consumption, in watts, on the unit's highest power setting. This is measured after the unit has been running for at least five minutes to ensure the compressor (if it has one) is running.

For comparison, a typical conversation is carried out at about 60dB, while city traffic is measured at around 80dB.

This is the maximum amount of water, in litres, collected in our test before the machine detected "tank full" and switched off. It's usually close to the claimed tank capacity but may be a little under or over that claim.

Shop Ethical rates the environmental and social impact of the company (not the product) using independent sources. This rating is not included in our total score. N/A means there is no rating for that company

The stated manufacturer warranty. Dehumidifiers should last at least 6 years so we rate a 1-year warranty as poor, and a 3-year warranty as reasonable. "Lifetime" warranties are good but are not as clear as a fixed term in years.

'Tested models' are those that we've tested and that are currently available in shops. In some instances, at the request of members and when products are still available on the second-hand market and via sites like eBay, we also include dehumidifiers that were previously tested but are now discontinued.

Recommended or typical retail price.

Calculated from our performance tests and based on an electricity cost of 40c/kWh. 

Based on the running cost and water extraction rate in our performance testing, and an electricity cost of 40c/kWh. 

Based on the amount of moisture the dehumidifiers can extract from the air, we've made size categories suitable for different room sizes.

Claim from the manufacturer for maximum room size the dehumidifier will serve. Sometimes in square meters and sometimes in cubed meters, and sometimes both.

The rate claimed at 30–32°C and 80% relative humidity.

The range of room temperatures in which the dehumidifier will function.

A filter on the air intake to prevent dust etc getting into the machine, and to help clear the air in the room.

A special mode designed to dry laundry placed nearby on drying racks.

This allows you to set the humidity level for the room.

Wheels or castors can make it easier to move the dehumidifier from room to room, but many are light enough to just pick up and carry.

Cord storage allows you to conveniently coil and store the power cord when the dehumidifier is not in use.

Most models have one or two carrying handles to help with moving them around.