Dehumidifier reviews

How dehumidifiers work

• Most dehumidifiers, including the models we tested, work by refrigeration. They draw air in, filter it, cool it to condense the moisture, and then reheat it and push the warmer, dryer air back into the room. This warms the room somewhat, but not as much as an actual heater.
• In winter you can use an electric heater and dehumidifier together; each will boost the effect of the other. Note that an unflued gas heater won’t help, as it releases moisture into the room.
• An air conditioner can be an alternative to a dehumidifier, as it dries the air as well as cooling or heating it, and may be a better option in hot humid climates where a dehumidifier’s heating effect could be undesirable.
• The colder the room, the slower the rate of water removal, so we test the units at different temperature/humidity combinations that reflect humid winter climates (between 8°C and 16°C and 65% to 90% relative humidity). Units that perform well in cold air should perform even better in warm air, so whether you live in a hot or a cold climate, the best performing models in our test should suit your needs.
• Dehumidifiers are rated to extract a certain volume of water (in litres per day); the larger and damper the room, the greater the water extraction it will need.

Brands and models tested

• DeLonghi CF05M
• DeLonghi CF08M
• Dimplex GDH-DEH30E
• Dry Home DH24
• Moisture Cure 928DB-20R *
• Nationwide 2020A
• Omega Altise ODE20

* Identical to the Suki WDH-928DB-20.

How we test

Water removal and energy efficiency

We set up our dehumidifiers in a temperature- and humidity-controlled test chamber. For each model, we measured 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). We found the best-performing models removed over twice the volume of water compared to the worst at the coldest temperatures.

Cold, humid conditions present a worst-case scenario for a dehumidifier; it's easier to extract moisture from warm air than cold air (which is why manufacturers usually quote removal rates at conditions which make their machines look the best, typically 30°C and 80% relative humidity). Models that perform well in this test will perform even better in warm climates.

Ease of use

Our lab testers also 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.