Gas humidifiers (Nafion)

How does a Nafion® humidifier work?

A Nafion® humidifier works on the basis of selective water permeation through an ionic polymer (Nafion™):

1. The dry gas flows through a Nafion™ tube or membrane.
2. On the outside of the membrane there is a water reservoir or controlled moisture source.
3. Water molecules migrate through the Nafion™ membrane into the gas stream.
4. The gas components themselves (such as N₂, O₂, CO₂, H₂, etc.) remain fully intact.

First-order kinetic humidification

As with drying, humidification follows a first-order kinetic reaction:

• The rate of moisture transport depends directly on the difference in water activity.
• As a result, the desired moisture equilibrium is reached very quickly (typically within milliseconds).
• Result: stable and reproducible relative humidity, even with varying flows.

Important advantage:
The gas stream is humidified without condensation, aerosols or droplet formation.

Why Nafion® humidification?

• Very accurate humidity control
• No disturbance of gas concentrations
• No consumables or atomisation
• Fast response time
• Suitable for continuous or dynamic processes
• Low maintenance and long service life

Nafion® humidifiers are widely used in:

• Calibration of gas analysers
• Fuel cell and hydrogen testing
• Sensor development
• Climate and materials research
• OEM measurement and control systems

Difference between BE, MH and FC Nafion® humidifiers

Although all types use the same membrane principle, they differ in construction, capacity and field of application.

Key specifications

BE series humidifiers (braided exchanger)

Passive humidification via the environment or a water source

• Nafion™ tubing in a compact exchanger
• Humidifies gas to equilibrium with the environment or connected water source
• No active control or heating
• Simple, robust and compact

Typical applications

• Basic calibration setups
• OEM systems
• Laboratories where simple humidification is sufficient

MH series humidifiers (membrane humidifier)

Active and accurate humidification for analytical applications

• Nafion™ membrane with controlled water chamber
• Suitable for stable and reproducible RH settings
• Works over a wide flow range
• Very accurate at low and medium flows

Typical applications

• Calibration of gas analysers
• Sensor validation
• Laboratory and R&D applications
• OEM measuring instruments

FC series humidifiers (fuel cell humidifiers)

High-capacity humidification for energy and hydrogen applications

• Designed for higher flows and continuous load
• Robust construction with high moisture transfer capacity
• Suitable for hydrogen, air and process gases
• Widely used in fuel cell and electrolysis testing

Typical applications

• Fuel cell testing
• Hydrogen technology
• Energy research
• Industrial test setups