Controlling humidity inside enclosures and equipment is essential to protect both sensitive devices and valuable items. From electronics and optical systems to musical instruments, museum displays and stored materials, unmanaged moisture can lead to condensation, corrosion, distortion or long-term degradation.

Traditional approaches often add complexity, require ongoing maintenance, or struggle to maintain stable conditions over time.

We take a different approach: maintenance-free humidity control engineered specifically for enclosed spaces. This website provides clear, practical guidance on stabilising internal conditions, preventing condensation, and selecting the right solution using solid-state electric micro dehumidifiers and long-life passive humidity buffers.

Whether you are designing new OEM equipment or protecting valuable contents, you will find proven methods, reliable technologies and straightforward selection tools that deliver consistent performance without ongoing servicing.

Our solid-state Rosahl micro dehumidifiers operate from -20° C to +50° C and actively remove moisture from small sealed or semi-sealed enclosures from 250ml up to 8m³ without using compressors, refrigerants or replaceable desiccants.

Unlike heater-based drying or silica gel systems, membrane dehumidifiers are designed for long-term operation in closed cabinets where moisture must be actively controlled rather than periodically absorbed. They work continuously and do not need replacing.

Rosahl solid state membrane dehumidifiers are designed and manufactured in Japan by the Mitsubishi Electric Corporation.

Designed for industrial and commercial applications, Rosahl membranes offer a long-term solution to humidity control for enclosures. Rosahl products consume very little energy compared to other types of humidification. This means they will run 24 hours a day, 365 days a year, continuously extracting moisture from an enclosed area without incurring major energy costs.

ROSAHL dehumidifiers are:

Rosahl is a unique family of electric micro-humidity controllers for enclosures where maintenance-free drying is a key factor.

Rosahl uses a specialised ionic membrane like that found in fuel cells, chemical engineering, water improvement and similar industrial processes. It works as an ionic pump to move humidity into or out of a sealed enclosure.

1. Electrolysis – When a 3 Volt D.C. charge is applied to the solid-state membrane, the moisture dissociates into hydrogen ions (H+) and oxygen.
2. Ionic membrane action – The hydrogen ions (not hydrogen gas) migrate through the membrane to be discharged outside the enclosure where they react with oxygen in the air to form water vapour.
3. Enclosure is dehumidified – With zero air exchange, the process removes the moisture in the enclosure to the required level.