Compressor vs Desiccant Dehumidifier: Which Suits Your Room?

How each type works

Meaco’s manual for the ABC range describes the compressor principle: a fan draws humid air across a filter and through an evaporator, where the air is cooled below its dew point so that water vapour forms as condensate on the coils and flows into the tank, and a condenser then reheats the cooled, dried air. Recycling the room’s air through the unit repeatedly lowers its relative humidity.

Which? describes the desiccant type as using a wheel that absorbs moisture from the air, with an internal heater and fan that drive the moisture off the wheel so the cycle repeats. That heater explains two things in the manuals: EcoAir says its desiccant models release slightly warm air, and Meaco’s DD8L Pro asks you not to unplug it until it has finished cooling down.

Normal heated rooms and colder rooms

Which? says refrigerant models typically struggle in colder spaces, such as cellars, and that desiccant models work in both warm and cold ones. Electrical Safety First says compressors work best in warmer temperatures, and desiccants perform better in cooler or unheated environments. The makers’ own limits show how the line falls: the compressors in our listing print lower limits of 3°C (Ebac), 5°C (Meaco, Pro Breeze, NETTA) and 15°C (EcoAir DC12 MK3), while all four desiccant models print 1°C.

No source gives a single cut-off. EcoAir’s DC12 MK3 manual gives 15°C as its minimum ambient temperature and says it defrosts periodically below that, and Pro Breeze’s product page says desiccant models are more effective below 15°C and compressors more efficient above 20°C. Those are makers’ statements, they differ from one another and we have not tested them. Meaco’s ABC manual does not recommend use below 5°C. For a room that is regularly colder than about 15°C, a desiccant model is the safer reading of the evidence; for a heated room, either works and the compressor is usually cheaper to run.

Why capacity claims differ

A litres per day rating is the water removed in 24 hours in a stated test room, and the test room differs by type and by maker. In our listing the compressor models that print conditions use 30°C and 80% RH (the Meaco Arete One 12L and ABC 10L, the Pro Breeze PB-18 manual and the EcoAir DC12 MK3), while the desiccant models use 20°C and 60% RH (EcoAir’s three, and Meaco’s DD8L Pro). A 12 L rating at 30°C and 80% RH and an 8 L rating at 20°C and 60% RH therefore describe different rooms and cannot be compared as they stand.

Meaco’s own pairs of figures show the effect. The Arete One 12L prints 12 L at 30°C and 80% RH but 7.5 L at 27°C and 60% RH, and the DD8L Pro prints 2.12, 5.4 and 7.97 L/day on fan speeds 1, 2 and 3 at 20°C and 60% RH. The 7.5 L and 7.97 L figures sit close together, but at different temperatures, so they are not proof that the two machines would remove the same water in your room. Which? tests extraction at 21°C and again at 10°C so that cold performance can be seen, but its results are behind a paywall and Shopicks has not used them.

Input power and running-cost considerations

Rated power in our listing runs from 165 W to 330 W for the compressors where it is printed, and from 231 W to 670 W for the desiccants (the DD128 also lists 25 W while it samples the air). The DD8L Pro varies with fan speed, 231 W at speed 1 and 623 W at speed 3, and the DD1 Simple MK3 draws 300 W in low mode and 580 W in high. Which? says desiccant models are more expensive to run than refrigerant ones, and Electrical Safety First says they may use more energy overall.

Energy used is rated power in kilowatts multiplied by hours. As an illustration, a 165 W compressor drawing that power for 8 hours would use about 1.3 kWh, and a 580 W desiccant model drawing its high-mode figure for the same time about 4.6 kWh. These are constant-power scenarios built from the makers’ printed wattages, not measurements and not maximums. Actual use varies with the room conditions, the mode selected and how often the humidistat switches the machine on and off. Multiply a figure by your own unit rate to get a cost, and remember that a desiccant model also gives out heat that may offset some heating in a cold room, which we have not measured.

Weight and portability

The compressors in our listing are listed at 9.5 kg (EcoAir DC12 MK3) to 13 kg (Pro Breeze 20L Smart and both Ebac models), and the desiccant models at 6 kg (EcoAir DD1 Simple MK3) to 8.7 kg (Meaco DD8L Pro). A lighter machine is easier to carry between floors, but weight is not the only factor. The Meaco Arete One 12L and the EcoAir DC12 MK3 list castors, the ABC 10L and the DD8L Pro sell castors separately, and the tank is heavy when it is full.

Noise

The printed noise figures run from 35 dB to 45 dB for the compressors and from 34 dB to 54 dB for the desiccants, but no maker prints the distance or the setting, and some print two figures without saying which setting each describes. Meaco’s ABC page says ‘from 36 dB’ while its manual says ‘maximum 40 dB(A)’ at one metre, and the DD8L Pro manual gives 40, 47 and 50 dB by fan speed. Treat them as indications of each maker’s own quietest setting, not as a ranking.

Which? rates quietness subjectively on the highest and lowest settings in its lab. Both types have night or sleep modes in some models. Meaco’s DD8L Pro manual adds that a dehumidifier will be noisier on a wooden floor than on carpet.

Maintenance

Both types need the same basic care: Meaco, Pro Breeze and EcoAir all say to clean the dust or air filter at least every two weeks, to empty the tank after use and to avoid blocking the air inlet. EcoAir says to replace the outer filter of a DD1 Simple about every 6 months, and Meaco says the HEPA filter supplied with the Arete One needs replacing roughly every 3 months.

The differences are small and practical. A compressor model should be kept upright and left to stand after being moved, which Meaco’s ABC manual puts at 30 minutes and the Arete One manual at six hours before first use, and several manuals say the sealed circuit holds a flammable refrigerant (R290) that only a trained engineer should service. A desiccant model needs a cooling-down period before you unplug it, and a drain hose should not be left outside below 1°C, which EcoAir and Pro Breeze both say.

Which household situations suit which

A flat or house heated through the winter, with a bedroom or living room to dry out, is the usual case for a compressor model, and it is the type with the most choice. A garage, outbuilding, cold hall or conservatory that is not heated is where a desiccant model earns its higher running cost. A home with both, such as a heated house with a cold utility room, may need to choose by the room that matters most.

A household that dries a lot of laundry indoors should read the laundry guide, because the laundry setting, the tank size and the clearance matter more than the type. A renter should read the condensation guide first, because Shelter says a landlord should look for the cause of condensation, and the type of dehumidifier is a second question.