Cleanroom ensures product quality

Modern research, development and manufacturing processes increasingly require environmental conditions in which the airborne particle concentration should not exceed specific limits.

Definition: What is a cleanroom?

Room with a defined concentration of airborne particles, designed and used in a way that the number of particles introduced into the room or originating and being deposited in the room is as small as possible, and in which other cleanliness-relevant parameters such as temperature, humidity and pressure can be controlled as required.” (VDI 2083-1)

The incoming air is processed by means of HEPA and ULPA filters to protect particularly sensitive products in research and industry against harmful environmental influences. To this end, also the staff in the cleanroom must comply with rules of conduct that dictate defined protective clothing.

Cleanrooms can cover areas of various sizes. From individual equipment to complete production facilities. The appropriate solution always depends on the requirements of contamination prevention.

The probably most important requirement is the airborne particulate cleanliness class. This is classified by specifying the maximum permitted number of airborne particles and divided into 9 ISO classes:

classification of cleanliness                                                                                    Source: DIN EN ISO 14644-1:2016-06

After the ISO class of the cleanroom has been specified, the type of air flow around the product must be considered.

Relevant flow principles in the cleanroom

1. Turbulent dilution flow: “Airflow not running in one direction. Air distribution, during which primary air entering the cleanroom or clean area is mixed with the air inside the room by means of induction.” (ISO 14644-1:2016-06) The filtered clean air is introduced into the cleanroom with a swirling effect and generates an increasing dilution of the particle concentration. With this flow principle, the staff’s behaviour according to cleanroom conditions is particularly important in order to ensure the required airborne particulate cleanliness class.

2. Low-turbulence displacement flow: “Unidirectional airflow, regulated airflow with uniform speed across the entire cross-section of a cleanroom or clean area, which is regarded as parallel airflow.” (DIN EN ISO 14644-1:2016-06) This is also called “laminar flow” and requires a low-turbulence inflow. In this procedure, the air escapes on the opposite side, normally consisting of a perforated double floor. From there, it returns into the recirculation device where it is filtered again. The low-turbulence displacement flow is particularly suitable for sensitive work areas.

Fan-filter modules (FFM) in cleanrooms

Fan-filter modules and clean air modules are used for clean air supply in clean environments. They filter the air and form the active elements in cleanrooms, clean air workstations, mini-environments or cleanroom transport systems.

fan filter units

Fan-filter modules (FFM) consist of three main components:

  • housing
  • fans
  • main filter (HEPA filter, ULPA filter); optionally pre-filter

Basic structure of cleanrooms

Each cleanroom environment has different installation conditions and requirements. Depending on those, the solution can feature solid wall elements (hardwall) or foil curtains (softwall) and equipment as well as come in different sizes.


Structure of a softwall cabin: PVC curtains shield the local clean air area against environmental influences. Several fan-filter-modules ensure the supply with “pure” air. The exhaust air can easily escape the cleanroom under the curtains.

cleanroom softwall cabin

Advantages of softwall cabins:

  • individual planning and installation
  • easy integration of work surfaces, shelves, wet work stations, separately enclosed inspection workstations as well as personnel and material locks
  • adaptation possibility for expansion of the production area
  • additional fan-filter modules can be installed easily

Structure of a hardwall cabin: Using a hardwall cabin, you can quickly create a clean environment for a specific process. Standardized segments allow simple setup of different cabin sizes.

cleanroom hardwall cabinAdvantages of hardwall cabins:

  • available in all purity classes
  • suitable for use in production areas with very narrow climate tolerances
  • precise examination of products or production processes possible

Advantages of a modular cleanroom system:

  • individual planning and installation
  • easy integration of work surfaces, shelves, wet work stations, separately enclosed inspection workstations as well as personnel and material locks
  • adaptation possibility for expansion of the production area
  • additional fan-filter modules can be installed easily

Advantages of a clean working zone:

  • the principle of the modular cleanroom can be transferred to work benches, individual cabins and mini-environments
  • individual modules are easy to connect and tailor to customer requirements
  • systematic use of the available space
  • provides an improvement in the purity class also outside the work surfaces

Cleanroom technology in its entirety has developed enormously in the economic field. There must be an appropriate ratio of quality and costs. The comparison shows that a conventional cleanroom is not always necessary.

The modular cleanroom systems prove to be an appropriate solution especially for small and medium-sized enterprises as they ensure a high degree of flexibility and the ability to modify the production areas. The transition between modular cleanroom systems and clean work zones is fluent.

Flexible cleanroom solutions

A cleanroom solution is vital for applications in research, development and production which must take place in particularly low-particle environments. However, the best option is not always a conventional cleanroom. Cost-efficiency, above all, is an important factor in this context. A rental cleanroom, for instance, could be a valid solution for small and medium-sized enterprises to avoid the high investment in a conventional cleanroom. Moreover, rental cleanrooms offer a high degree of flexibility to provide short-term solutions for order peaks, measuring and testing tasks.

Requirements on mobile rental cleanrooms:

  • easy assembly and disassembly
  • can be adapted flexibly
  • meets highest expectations

Find out more in our blog post: “Benefits and application areas of mobile cleanrooms”!

Grey room

The term grey room is used for spatially separate areas whose air purity is better than that of the surrounding spaces, but which do not necessarily offer cleanroom quality. In order to achieve the required cleanliness, special clean air modules have been developed. Thanks to a fine dust filter, coarse particles are filtered from the ambient air. These modules achieve a higher airflow rate and adequate air filtration.

Rental cleanroom

A rental cleanroom is perfect for temporary cleanroom requirements. Installed at your premises in little time, it provides the right process conditions for demanding production, measuring and testing tasks as well as for commissioning of machines, their cleaning and packaging of products.

This video shows how simple, fast and easy it is to set up a rental cleanroom:

CleanTent/Cleanroom tent

With a portable cleanroom tent (CleanTent), you can quickly and easily create a short-term cleanroom environment, for example, for service, repair and maintenance work on sensitive machines and products.

The inside of the COLANDIS CleanTent is supplied with pure air by means of two fan-filter modules and can therefore reach air purity class ISO 5 in the working area (approx. 1.2 x 0.6 m²).

Cleanroom summary

Each cleanroom environment has different installation conditions and requirements. You must find out which solution is appropriate for the described process. The solution can be a hardwall or softwall cleanroom or also a special solution.

However, what is important for product quality is not only the cleanroom itself but also the behaviour of staff, professional cleaning and continuous measurements as well as a successful qualification and re-qualification of the cleanroom.

Products & Services

Cleanrooms in production

The goal of zero-defects production in suitably clean production can only be achieved when the entire process chain is considered. Part cleaning and cleaning of complete assemblies and machines also plays an enormous role in this context. Over the last few years, many industries have increasingly been harnessing the positive influence of cleanrooms on product quality. The automotive industry and precision engineering, for instance, use cleanroom conditions for more and more process steps.

Suitably clean production does not exclusively mean production under cleanroom conditions. Of course, there is the question of cleanroom or grey room to increase product quality at every stage of the process. However, frequently, already consistently defined processes are a first step to protect the quality of products and save costs.

  • Please see our white paper “process development in cleanroom conditions” for more information on this topic!

process development

Relevant sectors

Working in the cleanroom

In order to meet the special requirements placed on cleanrooms or on special solutions such as minienvironments, all factors threatening cleanliness must be taken into account. Each individual element within the clean environment can contribute to the contamination of the complete system.

In addition to the processes and machines in the room, the human factor or staff in particular pose major risks of contamination.

clean environment

The essential behaviour rules in cleanrooms:

Employees in the clean environment not only need to wear special clothing but should also have been trained appropriately in dealing with processes and work steps in the clean environment. Rules for behaviour in the cleanroom are different in each company and must be aligned with the process and product quality. Hence, dress codes are not universally valid but must be checked and enforced.

Our view

“In summary, you can thus say that a clean environment is gaining importance in more and more areas. However, you must always consider the complete process chain. In the end, a complete cleanroom is not always necessary. Frequently, it is sufficient to resort to smaller, local solutions of cleanroom technology because “the best cleanroom is the one that you don't need.” (quote by Joachim Ludwig, COLANDIS GmbH)

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