+44 203 286 8189 steve.jones@westside-int.com
silent and vibration free electric dehumidifier

Silent and vibration free electric dehumidifier

Rosahl uses solid polymer ionic membrane (SPE) in the construction of its silent & vibration free electric dehumidifiers. The SPE uses electrolysis to remove water vapour when a low voltage DC supply is connected across the membranes’ terminals. The membrane has no moving parts so is a silent and vibration free dehumidifier, making it ideal for indoor environments.


The SPE consists of a proton-conductive solid polymer electrolyte and porous electrodes with a catalytic layer composed of noble metal particles. When a 3 Volt D.C. voltage is applied to the porous electrode attached to the SPE the moisture on the anode (dehumidifying) side dissociates into hydrogen ions (H+) and oxygen: the hydrogen ions migrate through the membrane to be discharged on the cathode (moisture discharging) side where they react with oxygen in the air, resulting in water vapour being discharged.  Similarly, if the membrane is reversed a humidifying effect is achieved.

As no liquid water is involved in the process, it is maintenance-free making it suitable for use in remote locations or where servicing is expensive or otherwise difficult. The membrane has a long operating life and has been tested to work from below -10 to +50C

Rosahl is suitable for use in steady state enclosures where the ingress of humidity is largely prevented, but where compressoror Peltier dehumidifiers may be too noisy or cause unwanted vibration.

Long-term solution

Micro dehumidifier membranes offer a long-term solution to humidity control for enclosures from below 500ml up to 4m³ (280 cu ft).  A range of models is available and some are 75% smaller than an AA battery, making them ideal for CCTV and similar applications.

Protect medical equipment from moisture damage
Rosahl works by electrolysis
Applications for Rosahl dehumidifiers

Where are Rosahl membrane dehumidifiers used?


Traffic control and display cabinetsExternal LED lighting
IP and CCTV cameras FTIR spectrographs
Mobile telecommunications outstationsLaser and Piezo systems
Protecting sensitive electro-optic devicesPrecision medical equipment
Museum displays and exhibition cabinetsOutdoor multimedia screens and displays

Advantages of Rosahl dehumidifiers