Desiccant Dehumidifier information

How do they work

Dehumidification is possible using two possible principles, Condensation with refrigeration style dehumidifiers and Adsorption with desiccant dehumidifiers. Desiccant dehumidifiers perform exceptionally well when used in cooler climates, or when a low dew-point, deep drying or low humidity levels are required. Since desiccant dehumidifiers do not produce water, they will work effectively down to sub zero temperatures. We offer a range of Commercial Ebac Desiccant Dehumidifiers including models DD200, DD300, DD400.

Depending on the environment Ebac Desiccant Dehumidifiers can lower humidity to 4%rh. We also supply a 
Remote Humidistat for accurate control.

Their operation is simplistic yet extremely effective and reliable. Air (Process Air) is drawn into the dehumidifier, where is passes over a wheel impregnated with Silica Gel. As the air passes over this wheel, any moisture present in the air, is absorbed into the Silica Gel wheel before leaving the dehumidifier as warm dry air. The Silica Gel wheel is continually, slowly rotating, typically at three revolutions per hour. As the wheel rotates a small portion passes through the regeneration segment. During this phase a second air stream (Regeneration Air) is heated to a high temperature before passing over the wheel. Any moisture present in the wheel is released into this air stream, this hot wet air is then exhausted outside the area being dried.

 - Circular spigots on the machines allow for easy connection of flexible or rigid ducting. Ducting should be as short as possible for maximum efficiency.

Manual / Automatic control is a standard feature within the DD range of desiccant dehumidifiers, and a remote humidistat can quickly and easily be connected for automatic operation and control The Ebac range of DD desiccant dehumidifiers are all manufactured from a high grade stainless steel, ensuring a rust free product when used in the most sever of applications The spigot connectors allow quick and easy installation All models incorporate a high efficiency patented PPS Rotor. This design incorporates a 82% active Silica Gel to ensure optimum performance over the equipments wide operating range of environments. All desiccant rotors supplied by EIPL are washable, and designed for high performance / long life.

Explanation of inlets & outlets on the DD200, 300 & 400

  • The process air inlet is the air taken from the actual space. With this you do not require ducting but it could be used for example if the dehumidifier were in one room but you wanted to draw air from an adjacent room.
  • The process air outlet is the dry dehumidified air that goes back out into the space. With this you do not require ducting but could be used for example if the dehumidifier were in one room but you wanted to dehumidify an adjacent room.
  • The regeneration inlet DD400 only also allows air to be drawn from the space, but to increase efficiency of the dehumidifier you can also connect 130mm ducting to draw air from the outside of the space and into the dehumidifier. You don’t have to do this but it is an option and you would require the adaptor plate.
  • The regeneration air outlet is the hot wet air being discharged to the outside. This does require either the 70mm or 102mm high temperature flexible hose depending on the model but it does not require an adaptor plate as a spigot for attaching the hose is fitted.

The simple installation is to only have one hose and that is to get rid of the hot wet air externally. However if you want to increase efficiency (this is an option on the DD400), in other words to have a quicker rate of dehumidification and therefore reduce running costs you could fit a hose to the regeneration air inlet which requires the adaptor plate. In doing this it does mean cutting/drilling 2 holes through a wall, one to take the 70 or 102mm wet air out hose depending on model and another to take the 127mm inlet hose. This is a matter of choice only on the DD400 as the regeneration air inlet for external air into the unit is not essential but an option. 


In mounting the humidistat I would recommend that it needs to be located away from the dry air air-stream leaving the dehumidifier otherwise it will give a false room humidity level.