FAQ - Frequently Asked Questions

1. What is a clean room?

The term clean room refers to a room in which the number of particles in the air is limited by so-called filter fan units (FFU, also known as flow boxes) in order to protect certain work processes or products from contamination.

2. Where do clean rooms come from?

    It is believed that the need for higher air purity arose for the first time in the small series production of optical parts. At the same time, medicine probably recognized that contamination and pathogens, which are also transmitted through the air, can have an impact on the survival or death of a patient in the operating room. The first real clean rooms then probably found their origin in medicine.19

    3. What is an ISO class?

    The ISO EN 14644-1 standard defines nine clean room classes, which are determined by a maximum value of the particle load in the air per m³. The degree of cleanliness of a clean room is thus determined by ISO classes. Overall there is ISO 1 to ISO 9, with ISO 1 representing the highest purity and ISO 9 the lowest. 20

    Reinraumklassen nach ISO EN 14644-1

    DIN, ENISO. "14644-1: 2016-06: Cleanrooms and associated cleanroom areas - Part 1: Classification of air cleanliness by particle concentration (ISO 14644-1: 2015); German version."

    4. What is a HEPA filter?

      HEPA is the abbreviation for High-Efficiency Particulate Air/Arrestance, i.e. a highly efficient particle filter. HEPA filters were originally developed for nuclear bunkers in the 1940s to filter contaminated particles from the air so that they did not get inside the bunker 18 22. They remove over 99.995% of all particles in the Most Penetrating Particle Size, typically 0.3 μm. Larger particles are separated practically 100%. 9

      5. How do I control the filter fan units (FFUs - clean room enclosure & laminar flow box)?

        The FFUs are controlled directly on the device using a 3-stage controller. These three levels are divided into a volume flow of 600 m³/h on level one, 800 m³/h on level two and 1000 m³/h on level three. With this very easy control, no training is necessary and a minimum level of cleanliness is always guaranteed with 600 m³/h.

        6. Which profiles are used for the laminar flow box and for the clean room enclosure?

          For both devices we use open, 45 mm type B aluminum profiles.

          7. What material is the paneling made of?

            The standard paneling of the laminar flow box is made of Plexiglas. For the clean room enclosure, we use monolithic PVC curtains. Other trims can also be installed as needed.

            8. What is the advantage of curtains in a laminar flow box?

            The use of laminar flow boxes with curtains offers the advantage that you can optimally organize your workplace. You can feed in cables, hoses and other inputs and outputs flexibly from any side.

            9. What is the advantage of a monolithic curtain vs. slats?

              Louvres are often pushed to the side during use and thus reveal the clean room atmosphere. With a monolithic curtain, you lean under the curtain and thus ensure maximum cleanliness even while working.

              10. How often does the filter of the FFUs have to be changed?

                The main filter change (HEPA 14) of the filter fan units depends on the surrounding atmosphere. If the flow box is kept in a clean atmosphere, a filter change will be necessary every 3-4 years. In a rather dirty atmosphere, a filter change is recommended every 1-2 years. The pre-filter should be washed out under running water every 6 - 12 months.

                11. How do I change the HEPA-14 filter?

                To replace the HEPA-14 filter, the Filter Fan Unit is lifted, the old filter is removed and the new filter is placed. Make sure that at least two people are involved in changing the filter due to the weight of the FFU.

                12. Should my clean room enclosure fit tightly or leave a passage for my optical table?
                  The close-fitting clean room enclosure has the advantage that it permanently achieves a higher degree of cleanliness than the walkaround variant, since significantly less dirt is brought in by people. 

                  The advantage of the walkaround variant is that it is more convenient to work with.

                  13. Can additional elements such as monitors or lamps be attached?

                    Yes, elements such as monitors, lamps, power strips, shelves and other elements can be attached to the open profiles with the 10 groove.

                    14. Is there a stand for the laminar flow box?

                      Yes, our laminar flow box is available both as a tabletop device and as a standalone device, with castors if required.

                      15. Is it possible to build a breadboard into the laminar flow boxes?

                        Yes, on request we can integrate a honeycomb breadboard directly into the laminar flow box for an optimal clean room workplace in optics and laser technology.

                        16. Are our products also suitable for UV lasers?

                          Yes, non-outgassing TPE curtains can be used for highly sensitive UV lasers.

                          17. How does the Nordair air purifier work?
                            Feel free to watch our YouTube video:


                            18. What makes a good air purifier?
                              With a room air cleaner, there are two main points to consider: volume flow and the type of filter. The volume flow should be as high as possible in order to be able to filter the room volume several times an hour. In addition, it is necessary to use an efficient filter with a high degree of separation. HEPA-14 filter is recommended here (filters 99.995% of all airborne particles such as viruses and bacteria). 2

                              Furthermore, one should also pay attention to the volume with the corresponding volume flow. 

                              19. How much volume flow do I need?

                                The volume flow should be at least high enough to clean the room air six times an hour 2. Here is an example calculation: https://www.youtube.com/watch?v=DYdV0uZu62w&t=3s

                                20. Do I require a maintenance contract?

                                  No, we attach great importance to the fact that all our products can be serviced quickly and easily (changing the filter and pre-filter).

                                  21. How often does the filter need to be changed?
                                    The main filter (HEPA 14) of the room air purifier should be changed every 1-2 years during normal use. The filter change can be carried out within 5 minutes.

                                    In principle, the pre-filter for the coarse particles does not have to be completely replaced. Here it would be important to wash out the pre-filter and running water every 3-6 months and let it dry before use. However, if the pre-filter is damaged, it must be replaced for further use.

                                    22. Is there a draft in front of the device? 

                                      No, there is hardly any draft in front of the room air purifier. On the one hand, the room air cleaner has a huge filter surface. As a result, the air speed can be kept low with a consistently high volume flow. On the other hand, the exiting air is almost laminar, i.e. low in turbulence. Humans particularly feel turbulence on their skin, so this low-turbulence air hardly draws. 2

                                      23. Why don't you use additional UV radiation?

                                        UV-C radiation has proven to be an effective means against viruses and bacteria. However, UV-C radiation is so strong that it has an ionizing effect. If you treat the air in the air purifier with UV-C radiation, ozone can be created. Ozone is an aggressive oxidizing agent that can damage the lungs. In addition, the UV radiation needs time to effectively render viruses and bacteria harmless. As a result, a high volume flow cannot be guaranteed and the room air is not filtered often enough. 23

                                        24. Is there any risk in disposing of the filter? What do I have to consider?
                                          No, it is absolutely harmless to change the filter. The viruses die off after a short time in the filter. In addition, it takes a lot of energy to get viruses or other particles of this size out of the filter.

                                          We still recommend wearing gloves and, if necessary, a face mask, as larger dust particles or moisture can remain on the inside of the filter. 21

                                          25. Do I need instruction to operate the air purifier?
                                            No, the Nordair air purifier is straightforward to use with an on/off switch and a dial. Feel free to watch our YouTube video on how to operate the Nordair room air purifier:


                                            26. Does a room air purifier also help against pollen?

                                              Yes, the room air purifier is a very effective tool in the fight against pollen allergies, as it effectively removes pollen, bacteria, viruses, spores, fine dust and other particles from the room air.

                                              27. Is there a timer for turning it on and off?
                                                We recommend a digital timer for the power connection. This also allows weekdays to be displayed. We will be happy to supply these directly on request.

                                                28. What delivery time can I expect?

                                                  You will receive the room air purifiers within a few days of ordering. The delivery of cleanroom products takes an average of 4-6 weeks. We attach great importance to always keeping our inventory high so that we can deliver reliably and quickly. In the case of individual requests, we will actively consult with you about the delivery and the delivery time.

                                                  29. How is the cleanroom enclosure delivered?

                                                    The clean room enclosure is delivered in individual parts on pallets. The assembly can be carried out with the supplied tools and the assembly instructions within a few hours without previous knowledge.

                                                    30. Is it possible to have the clean room tent assembled by you?

                                                      We are happy to offer you assembly as a service. Please contact us for an individual offer.

                                                      31. How is the laminar flow box delivered?
                                                        The laminar flow box is delivered assembled and ready for use.