Laminar Flow


Laminar Flow is a smooth uni­directional current of ultra clean filtered air with a constant velocity of 0,45 ± 0,1 m/s over the whole clean working area.

The essential part of Laminar Flow equipment is the HEPA* filter which removes minute particles (aerosols) and microorganisms and cleans the air.

This Laminar Flow enables practically microbe- and particle-free conditions to be achieved.

* HEPA = High Efficiency Particulate Air-Filter

Direction of current

Horizontal Laminar Flow

Due to good sight and accessibility it offers ideal conditions for working with small objects.

Gives very good protection for work with large objects. It can be easily ac­com­mo­dated at finishing areas and filling lines and is therefore widely in use.

Vertical Laminar Flow

Functioning principle

Functioning principle

Air-borne particles cannot enter the clean zone because it is constantly flushed with clean air. Particles generated in the clean zone are flushed out with the air current.

Progress in cleanroom technology
Integrated Laminar Flow air-conditioning

The question of optimization

It appears sensible, that when an a­sep­tic working area has to be supplied with clean air, the air could also serve for air conditioning and aeration of the rooms.
The aeration rate is detemined by the number of persons present in the rooms and proceeds over a Laminar Flow unit.

The planning of the cleanrooms involves the calculation of the air replenishment by the Laminar Flow equipment. Air coolers on the air-intake side of the equipment solve cooling problems without the necessity of installing additional ducts.

Even when modernising existing production areas, solutions can be found which satisfy both purity demands and running economy optimally incorporating state-of-the-art technology.

That's the end!

Air current: Normal (no danger of contaminating the environment):
out of the clean room (white) through the air locks to the outside.
Special (possible dangers of contaminating the environment):
through the air-lock into the clean room. exhaust air must be treated.


  • rel. humidity > 55 %:
  • rel. humidity < 45 %:
  • almost no electrostatic problems
  • almost no corrosion problems
Air purity: High proportion of
recirculated air
  • high purity
  • filter life long
  • relative simple air conditioning

The following has been written for persons who are responsible for the clean room
or for personnel working in the clean room.

Clean room: why...?
There are so many sources of dust and air impurities sur­­round­­ing us that it is not possible even to estimate where they all come from or to determine how detrimental they are to the type of work in which product cleanliness is of vital im­por­­tance. The clean room is designed to eliminate all these uncertainties so that good quality is ensured and working procedures are reproducible.

Design of the clean room
When the standard of cleanliness needed is known, it is possible to design a clean room for the required purposes. The room has a floor, walls and ceiling and the material used for them must be durable, smooth and easy to clean. All angular joints e.g. between the walls and ceiling must be rounded so that dirt is not trapped and cleaning can be carried out easily. Doors and windows must also comply with these criteria. The materials used must be of a quality which is suitable for the clean room construction and they must be resistant to all substances employed and the conditions used in the equipment (humidity, disinfectants etc.).

Clean room and man
The people working in the clean room must be given particular attention because they are the greatest source of con­tam­i­na­tion, which is continually liberated from their clothes, their skin, their hair und their breath. Special attention must be paid to these sources when conceiving the technical requirements for specific production processes. Clean room clothing has been developed for all types of activitites, but each person must be aware of his own responsibility with regard to correct behaviour and hygiene.

Clean room and ventilation
The requirements needed for the processes being employed largely determine the air conditions: when the relative humidity is less than 45% corrosion can not take place but electrostatic charging is possible. Above 45% relative humidity this is reversed. Temperature and humidity are factors which also affect the well-being of the personnel. The purity of the air should be determined by the requirements needed for production in order to garantee a high quality and long shelf life of the product. This factor has no influence on the working comfort of the personnel.

Integrated laminar flow ventilation
This type of clean room ventilation combines air conditioning with air purification. Purified clean air needed for product protection is warmed, cooled, humidified or dried so that other process requirements can be fulfilled. The air conditioning can be adjusted to suit specific production requirements. The amount of air needed to be delivered is determined by the number of personnel (c. 100 m³/h per person), the amount of exhaust air and the achievable air flow from the clean room to the surroundings.

Examples of use for Laminar Flow

Physiology, Mikroscopy and Preparation of Samples

Physiology, Mikroscopy and Preparation of Samples



Laminar Flow clean air current from the left to the right over the working area to the air intake filter wall.

Example of use for Laminar Flow