Rosahl MDL-3 Electric Micro-Dehumidifier

The MDL-3 by Rosahl is a compact flat-membrane dehumidifier module for volumes of up to 0.5m³ (500l)..

Operation Principle

Like all Rosahl dehumidifiers the MDL-3 is based on a solid-state polymer membrane. When supplied with a 3V DC voltage, moisture on one side is being decomposed into Hydrogen ions and Oxygen, the Hydrogen ions pass the membrane and recombine with air Oxygen to moisture again on the other side and get discharged.

Storage of 3D-Print Filament Spools

With an applicaple air volume of 500 liters the Rosahl MDL-3 membrane is suitable for storage of single filament spools e.g., in a 50-80 litre "Kreher® Waterproof Storage Box" with space for ~15-20 spools (alternatively Ikea "Samla" box, which has to be sealed separately). With pre-dried filament spools (especially spools made of cardboard contain quite high moisture) a continous storage at approx. 15% rH and less is achievable. We made a 3D printable mounting frame for the MDL-3 membrane plus USB-C power supply module, see the further product images. The 3D models can be downloaded on Printables.com.

Note:

The achievable humidity level in a storage box or in the Bambu Lab AMS depends on both the sealing of the box as well as on the outside room humidity level. In regions of high room humidity it can be beneficial to "oversize" the membrane more to achieve the desired humidity level inside. If you are unsure about the suitability of a certain membrane for your particular storage box and/or application, please reach out to us in advance.

Power Supply

The Rosahl MDL-3 dehumidifer requires a 3V DC supply voltage and draws in continous operation i.e., when the moisture level in the volume stabilized to a low level, just around 2W power.
Due to the membrane being intrinsically hygroscopic, it absorbs humidity if no supply voltage is present. This moisture needs to be discharged on startup and leads to a significantly higher inrush-current that the regular operating current. During startup the supply voltage shall still not drop below 2V, otherwise moisture discharge is not possible or significantly delayed. Suitable current supplies are fold-back current limiting sources, which regulate the output current further down than pure constant current sources and hence maintain a certain output voltage. We provide suitable USB-C voltage regulator modules with fold-back current limiting, which can be used stand-alone or mounted into our 3D-print mounting frame/covers.

• USB-C 5V->3V/3A voltage regulator module for Rosahl MDL-3 dehumidifier

Technical Parameters MDL-3

Applicable Volume	~0.500m³
Dehumidifying Performance	4g/day
Supply Voltage	2.9-3.3VDC
Power Consumption	2W (20°C/60%rH)
Rated Current	900mA (dep. of rH)
Inrush Current	7A
Operating Temperature	-10°C - +50°C
Connecting Type	Solder/flat connectors

 

 

Further Information

• MDL-3 Produktspezifikation
• Instruction Manual

Scope of Delivery

The Rosahl MDL-3 dehumidifier comes as single unit.

Complete Kits

A full kit with the MDL-3 membrane, VREG2 USB-C power supply module and assembly material is available as well.

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Manufacturer Information
RYOSAI TECHNICA CO., LTD., 8-1-1 Tsukaguchi-Honmachi, Amagasaki-City, Hyogo, 661-0001 Japan, Email: ryosai_sales@ryoyo.co.jp