How does a Nafion® humidifier work?
A Nafion® humidifier works on the basis of selective water permeation through an ionic polymer (Nafion™):
- The dry gas flows through a Nafion™ tube or membrane.
- On the outside of the membrane there is a water reservoir or controlled moisture source.
- Water molecules migrate through the Nafion™ membrane into the gas stream.
- 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
| Series | Application / features | Key specifications |
|---|
| MH™-Series (Water-to-Gas) | For flows up to approx. 20 l/min. | Output up to 99% RH · Flow up to ~20 l/min · Temp. up to ~80 °C · Pressure up to ~80 psig (5.5 bar) |
| FC-Series (Large Flow Gas-to-Gas) | For larger flows, up to thousands of l/min. | Output up to 99% RH · Flow up to ~15,000 l/min · Temp. up to ~80 °C · Pressure up to ~45 psig (3 bar) |
| BE-Series (Ambient Moisture Gas-to-Gas) | For small flows, uses ambient moisture. | Flow up to ~2 l/min · Temp. up to ~80 °C · Pressure up to ~90 psig (6 bar) · Output: up to ambient RH |
| MD (Gas-to-Gas Controlled RH) | For controllable RH in small-scale applications. | Flow up to ~4 l/min · Temp. up to ~80 °C · Pressure up to ~90 psig (6 bar) · Output RH ~90% of the humid gas stream |
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