For the manufacture of special crystals used in an innovative imaging process, a leading medical technology manufacturer required a cleanroom complex with a total of 715 m² of cleanroom space in a new-build facility. The project called for five cleanrooms rated ISO Class 6 and ISO Class 7, extensive airlock zones, and a high-performance technical infrastructure.
Weiss Klimatechnik planned the €4.5 million project and delivered it fully operational as the general contractor.
BIM as the basis for coordinated planning
Planning was carried out entirely using the BIM method from the very start of the project. This made it possible to integrate shafts, supply lines, and electrical components into the supplied building model without any clashes. The shared data platform facilitated coordination between the trades involved and at the same time laid the foundation for efficient building management later on.
As the project progressed, the digital planning approach proved particularly advantageous when subsequent adjustments were required. Despite additional requirements and scheduling changes on the part of other trades, project progress was managed reliably.
Cleanroom technology with a high level of integration
The original contract covered two ISO Class 6 cleanrooms and three ISO Class 7 cleanrooms. In addition to the cleanroom enclosure itself, the scope of supply included a personnel airlock together with nine material airlocks and pass-through hatches.
The cleanrooms themselves were built using proven modular system components. Particular attention was paid to the planning and construction of the personnel airlock. Intelligent design details were integrated at this central point in the cleanroom to actively support cleanliness. These include lockable compartments optimized for laptops and tablets, drink holders, and a water dispenser integrated into the furniture. An air shower was installed to remove particles from personnel as they move from the ISO 7 area into the ISO 6 area.
Various changes and additions arose over the course of the project. These included, among other things, the steelwork for a services platform above the cleanroom and the planning of all media piping into the cleanroom, including process water, deionized water, and compressed air. In addition, the contract was extended to cover electrical planning, including outlets and lighting for the entire cleanroom area, and the cleanroom's WHG-compliant flooring (in line with the German Federal Water Resources Act) was extended across the entire floor.
Air conditioning technology for high heat loads and demanding processes
The high heat load of the process equipment presented a particular challenge. The cleanroom technology was therefore connected to a customer-supplied decentralized cooling system.
To improve energy efficiency, exhaust air streams that are not process-critical are bundled together and routed to a central air handling unit for heat recovery. Contaminated, chemically aggressive exhaust air from the process, by contrast, is discharged separately through resistant plastic ducting and dedicated fans. A large portion of this is routed to a customer-supplied treatment system, where it is thermally treated.
This solution combines process safety requirements with economical system operation.
Precisely coordinated pressure cascades and airflow
More than 40 Filter Fan Units with H14 filters and around 50 individual extraction points were installed to achieve the required cleanliness classes. Overall control is handled by a Siemens S7 controller.
Setting up and balancing the pressure cascades between the individual cleanroom areas required particular attention. Numerous technical penetrations and the integration of various pieces of process equipment had to be implemented in such a way that the cleanroom classification is permanently maintained. One machine, for example, was set into a cleanroom wall so that its servicing side lies outside the cleanroom, in the gray area. This allows the machine to be serviced without any loss of cleanroom status. Many other machines required process media line penetrations at the height dictated by the machine; in these cases, sealing was carried out using custom individual solutions.
The overall system also features an energy-saving reduced-operation mode that keeps room pressure stable even at reduced air volumes and prevents contamination.
Complex project delivered on schedule
Despite the additional scope of work, logistical challenges, and the parallel activities of numerous trades, the cleanroom complex was handed over on schedule and ready for operation.
Dirk Schüßler, Lead Project Manager at Weiss Klimatechnik, sums up with satisfaction: “I am pleased that we were able to complete the various additions and manage the logistical challenges on schedule and to the complete satisfaction of our customer.”