Which boat dehumidifier?

Practical Boat Owner Magazine tested several dehumidifiers for use in boats and published the results in the December 2009 issue. The DD122 with its desiccant technology was the clear winner, but this has now been replaced by the DD8L model, which has won the award every year since.

A cheap domestic compressor dehumidifier will struggle to keep your boat dry and free from mildew during winter storage, because it will be compressor based and wont work below around 5 degrees, in unheated spaces like your boat. These new generation desiccant adsorption dehumidifiers are pretty well perfect – but now there are two to chose from!

DD8L Junior Dehumidifier

Compact desiccant dehumidifier.

Exactly the same specification as the DD8L, but without the silver nano particle filter and ioniser.

Extraction rate up to 8 litres per day. Ideal for all boats up to 50 ft., caravans, motorhomes, garages, workshops and homes up to 5 bedrooms. 12 month warranty.

Dehumidifier DD8L Junior £169.99
[Add to Basket]

DD8L Dehumidifier

High performance desiccant dehumidifier.

Motor Boat Monthly Magazine November 2011 said “…a perfect on board dehumidifier.”

Extraction rate up to 8 litres per day. Recommended for use inboats, garages, workshops and homes up to 5 bedrooms. With anti-bacterial silver nano filter and an ioniser to help keep the air clean, especially important for anyone who suffers from allergies.

Offers a built-in humidistat and various timers and pre-sets so, if you fit a drain hose, is a perfect ‘plug in and forget’ solution. Once it has taken humidity down to the selected level, it switches into monitoring mode using minimal power, coming back on when needed.

Dehumidifier DD8L £194.99
[Add to Basket]

Here are some of our favourite features for both models:

  • Desiccant adsorption technology – works at low and even sub-zero temperatures
  • Fully automatic humidistat control for economy
  • Tank or continuous drainage modes
  • Auto restart after power interruption means you can set it on a timer and leave it unattended
  • Lightweight and compact – no castors so it doesn’t roll around!
    Maintenance free

All of these features make them brilliant dehumidifiers for boat, caravan, garage or any unheated area.

 Dehumidifier DD122Dehumidifier DD8L
Extraction rateUp to 8 Litres per dayUp to 8 Litres per day
Temperature operating range1 - 40°C1 - 40°C
Power consumption30/330/650W depending on running mode * See note below30/330/650W depending on running mode
Tank capacity2 litre with auto-cut-off when full. Water level indicator2 litre with auto-cut-off when full. Water level indicator
Continuous drain optionYes. 1 metre x 12mm hose includedYes. 1 metre x 12mm hose included
Dimensions w x d x h35 x 180 x 50cm35 x 180 x 50cm
Humidistat settingsAuto 55 to 60%RH
High 45 to 50%RH
Auto 55 to 60%RH
High 45 to 50%RH
Fan settingsLow or highLow or high
Laundry drying modesSaving and turbo settings with powered louvreSaving and turbo settings with powered louvre
Auto restart after a power interruptionYes – can be used with external time switchYes – can be used with external time switch
Timer – to switch off after specified duration (e.g.for laundry drying)Yes. Up to 8 hoursYes. Up to 8 hours
FiltersWashable main filterWashable main filter
Internal anti-bacterial filter with nano sover coating
Electrical supply230V 50Hz230V 50Hz
PriceDehumidifier DD122 £164.99
[Add to Basket]
Dehumidifier DD8L £194.99
[Add to Basket]

Desiccant dehumidifiers have a higher power rating than compressor dehumidifiers, but when used in the UK for keeping a boat dry in winter, they use less power. This is because they extract water much faster than compressor types when the ambient temperature is below 15C.

These particular models have further energy saving features: they turn off when the required humidity is reached, but then operate the fan to sample the air for five minutes each hour. If the humidity has risen, they start dehumidifying, but if it is OK, they go back to sleep until the next sample.

The energy consumed by the dehumidifier is returned to the boat as heat, so they also have a modest warming effect.