This overall 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 details, see our article on how we test dehumidifiers.

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. 

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.

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 average power consumption in watts under set ambient conditions.

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.

We recommend dehumidifiers with an overall score of at least 70%.

This column shows which products have been discontinued and which are still available in shops. 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 models that were previously tested but now discontinued.

Recommended or typical retail price.

Calculated from our performance tests and based on electricity cost of 30c/kWh. 

Based on the running cost and water extraction rate in our performance testing, and on electricity cost of 30c/kWh. 

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

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.

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.