Especially the filter and air purification modules represent a very central success factor in the construction of cleanrooms and protection zones within a cleanroom facility. clean-tek invested years of development work in their own filter fan units (FFUs). They produce a high quality of supply air and reduce the particle concentration in cleanrooms or individual protection zones within a cleanroom facility. In the upper intake area, the air is optionally cooled by an attached cooler and optionally also pre-cleaned by a pre-filter. The intake air is then cleaned by a special HEPA filter and introduced into the clean room as a low-turbulence displacement flow.