…WSI-INS-22016.1

Installation Guide for M3M-EMM2

Rosahl Solid-State Dehumidifier

Safety and Regulatory Information

For Rosahl M3M-EMM2 Enclosure dehumidifier
Document No. WSI-INS-22016 V1
Manufacturer: Westside International Ltd.
Boston House, Downsview Road, Wantage, OX12 9FF. UK

enquiries@micro-dehumidifier.com            www.micro-dehumidifier.com

For Correct Usage

Please read this installation guide before installing the dehumidifier. Incorrect use will invalidate the warranty.

 General Safety Warnings

  • This product is intended for indoor use with sealed display or storage enclosures.
  • Installation requires the use of tools and basic technical skills. Not suitable for children or unqualified personnel.
  • DO NOT use silicone-based sealing materialsas they will permanently damage the membrane.
  • Do not touch, damage, or modify the membrane in any way.
  • Only use this product with supplied or approved components. Do not substitute the power adapter or modify the membrane or housing. Do not allow the membrane to become wet.
  • Do not reverse the electrical wiring (polarity), as this will permanently damage the dehumidifier membrane.
  • The VRS330 VREG2 power adapter includes electronic devices sensitive to electrostatic discharge (ESD). Only qualified personnel should remove or service it.
  • Do not use near rust inhibitors, vapour phase corrosion inhibitors or high-density organic gases as they will damage the membrane and reduce performance.

Electrical Safety

  • Power Input: 5V DC via USB-C (minimum 15W)
  • Operating Voltage: 3V DC (regulated via internal adapter)
  • The integrated VRS330 VREG2 adapter includes fold-back current limiting for safe startup.
  • Use only with a Class 2 power source or LPS (Limited Power Source) as defined in IEC 62368-1.
  • The adapter is not a USB Power Delivery (PD) compliant sink device. Use a standard 5V USB-C power supply if issues occur.
  • To disconnect power, simply remove the USB-C plug from the device or switch off the USB power adapter at the source.

Environmental Conditions

  • Operating temperature: -10°C to +50°C
  • Storage temperature: -20°C to +60°C
  • Humidity: 10–90% RH (non-condensing)
  • Altitude: Up to 2000 m
  • Not evaluated for outdoor use or exposure to liquids.

Maintenance and Servicing

  • This product is maintenance-free and contains no user-serviceable parts.
  • Do not open, modify, or attempt to clean the membrane or circuit board.
  • If the device is damaged or fails to operate, contact the supplier for support or replacement.

Disposal and Recycling

  • Do not dispose of this product with regular household waste.
  • Dispose of this equipment in accordance with local electronic waste regulations.
  • For European customers: The WEEE Directive covers this product. Return it to your supplier or designated collection point.

Regulatory Compliance

  • RoHS Declaration: Available
  • REACH Declaration: Available
  • Manufactured in the European Union and Japan (membrane)
  • USB-C cables with ferrite chokes are recommended

 

Installation Guide:

The M3M-EMM2 is an assembled and ready to use dehumidifier for mounting on the outside of an enclosure.

Overview and Installation

Our membrane dehumidifiers are suitable for use with a wide range of sealed display and storage enclosures to protect sensitive and delicate equipment. They are often used for 3D filament dry boxes and storage systems like the Bambu Lab AMS.

The main components are the plastic housing, a pre-wired USB-C power adapter board, the Rosahl dehumidifying membrane.

When mounted on the outside of a sealed enclosure and connected to a USB-C power source (not supplied), the dehumidifier expels moisture through the membrane. Installation requires a hole to be made in the enclosure wall through which the moisture is expelled. See below for guidance. The dehumidification process is silent, waterless, maintenance-free and has a low energy footprint.

CAUTION: it is important not to remove or reverse the electrical connections as this will damage the membrane. The dehumidifier membrane needs a 3V DC power source. It receives this from the integrated USB-C power adapter board which reduces the voltage from a standard 15-Watt USB power supply from 5 Volts to 3 Volts.

Assembly & Mounting Instructions

You can mount the dehumidifier vertically or horizontally on the side of the enclosure but ensure the USB connection is in your chosen location.

1.       Mounting Cover Components

The humidifier includes a four-part housing set, plus fixing template and three sealing rings:

  • Inner fixture – holds the membrane and USB-C power adaptor module
  • Outer cover – secures components in place
  • Threaded retaining ring holds the housing in position against the dry box
  • Power adaptor retaining bar

Compact housing for Rosahl -3M1R dehumidifier

 

2.       Marking and Preparing the Cut-out

Using the supplied template, find a good place on your dry box or AMS to  install the housing and mark either the centre of the hole when using a 42mm step-drill (recommended) or round hole-saw (can be risky with thin walls or brittle material), Alternatively, mark the outline of the hole while  drilling a sequence of small holes around the diameter and finishing with a file.

As a suggestion, if using an AMS or similar, consider removing the cover before drilling. Otherwise place foil over the lower part and close the cover.

When the hole is completed, slide through the assembled housing. One of the larger O-rings goes into a recess around the outer thread and another into the recess of the nut. Add the nut and screw together until the O-rings fit tightly.

Finally add a USB-C cable and connect to a USB power supply/charger.

 

Additional resources at https://micro-dehumidifier.com/documentation/

– Membrane dehumidifier user  manual RB-OP21004                                             Open PDF

– Membrane RoHS Declaration of Conformity                                                            Open PDF

– Membrane REACH Declaration of Conformity                                                         Open PDF

– Dehumidifier UKCA/CE Declaration of Conformity                                                Open PDF

– Power adapter board RoHS Declaration of Conformity                                         Open PDF

– Power adapter board REACH Declaration of Conformity                                      Open PDF

 

 

©Westside International 2026 All rights reserved. Specifications subject to change without notice.

www.micro-dehunmidifier.com    enquiries@micro-dehumidifier.com