Comparison of different air humidification technologies

In practice, various systems and technologies are used to ensure adequate humidity: nozzle atomisers, steam humidifiers, ultrasonic atomisers and evaporators are commonly employed principles that are used in both centralised humidification and in-room air humidification. Condair specialises in direct air humidification and primarily uses nozzle systems incorporating high-pressure and compressed air technology. The various systems differ in terms of energy consumption, maintenance requirements and humidification capacity.

2. Steam humidifiers

Evaporators produce steam in a heat-resistant plastic or stainless steel cylinder, in which the humidifier water is heated to 100 °C. Steam humidifiers are divided into three types: electrode, resistance and gas evaporators. Heating in the commonly used electrode and resistance evaporators is achieved using electrical energy, which is why the power consumption is quite high.

Rating: Steam humidifiers operate quietly but have high energy consumption. The service life of the steam cylinders is limited due to limescale build-up.

3. Ultrasonic humidifiers

In ultrasonic humidification, the water is excited into high-frequency vibrations by piezoelectric oscillating elements, causing water aerosols to emerge from the water surface in the form of a cold mist. The resulting aerosol is carried into the room air by a stream of air.

Review: The advantages of ultrasonic humidifiers are their low energy consumption and their silent, drip-free operation. The service life of the ultrasonic transducers is limited, so provision must be made for replacement parts. Fully demineralised water is required for operation.

4. Evaporative humidifiers

In evaporative humidifiers, the water is distributed evenly over a wicking pad, or the wicking pad becomes saturated to create a large surface area for the evaporation process. A fan draws the room air through the wicking pad. The humidification process takes place through evaporation on the surface of the contact medium. Fixed units are connected to the mains water supply. The contact medium can be stationary or rotating.

Rating: Evaporative humidifiers have a low power consumption. To prevent limescale deposits and the formation of a biofilm, cleaning and maintenance must be carried out regularly. The water should be changed daily.

5. Small mobile units

According to VDI 6022 Part 6, the use of small mobile units at workplaces is to be prohibited as a precautionary measure; unless the user provides verifiable evidence of safe operation.

All decorative water-based installations (e.g. water walls, fountains) also pose a high risk of respiratory exposure due to contaminated water if they are not properly supplied, cleaned and maintained. Special inspections and measures are therefore necessary to ensure safe operation.