Construction measure cleanroom: Modular solutions for rapid demand in the highest quality

Exterior view of the Liver and Infection Center at the University Hospital Düsseldorf (Photo: Cadolto Modulbau GmbH)

Interior view of a highly insulated single room at the Liver and Infection Center at the University Hospital Düsseldorf (Photo: Cadolto Modulbau GmbH)

Personnel lock before the isolation areas in the Liver and Infection Center at the University Hospital Düsseldorf (Photo: Cadolto Modulbau GmbH)

Seminar Room Liver and Infectious Diseases Center, University Hospital Düsseldorf (Photo: Cadolto Modulbau GmbH)

A cleanroom is a workplace with the highest quality requirements for the premises, surfaces, and cleanroom conditions. When planning cleanroom projects, developers face various challenges: the faster a cleanroom can be built, the more economical it is. Additionally, the entire building concept, including workflows within the rooms and the equipment of workstations, must guarantee the best possible work results and maximum product safety.

Cadolto offers modular cleanroom concepts tailored to the user, which can be constructed in a shortened timeframe while maintaining maximum quality — even during ongoing operations in surrounding areas.

Cadolto Modular Cleanroom Concepts

Proper planning and execution have a significant impact on the efficiency and effectiveness of a cleanroom. All workflows, including pressure and airlock concepts that control the flow of materials, personnel, and products, must be coordinated during planning and implementation.

With experience from over 770 modular projects and specialists from all trades, Cadolto supports the developer from the planning process to the turnkey handover of the cleanroom project. The modular construction specialists handle user coordination, the scheduling of all necessary trades, as well as structural calculations and foundation plans.

Execution according to the highest quality and safety standards is enabled by experienced staff from all trades. Furthermore, the modular construction company handles hygiene approval and certification by TÜV and LGA, and accompanies the developers until the new rooms are operational. The complete qualification of the cleanrooms is carried out by experienced partner planning offices.

Execution According to ISO 14644 and Good Manufacturing Practice (GMP)

Work and research activities in cleanrooms must meet national and international standards, which is why cleanroom classes according to DIN EN ISO 14644-1 and the guidelines of Good Manufacturing Practice (GMP) are applied.

Certification according to ISO 14644 is, for example, a prerequisite for chip manufacturing, while GMP guidelines apply to the production of products intended for human use, such as medications or certain foods.

Cadolto manufactures for cleanroom production, semiconductor technology, and micromechanics according to ISO 14644 classes ISO 9 to 4. Special attention is paid to particle prevention. Additionally, Cadolto's modular buildings meet requirements for biotechnology, stem cell research, and pharmaceutical production according to GMP up to Class A. Higher cleanliness classes are achieved with FilterFanUnits or laminar flow ceiling systems, and are separated by airlocks and access controls — including monitoring — in stages. Moreover, Cadolto's buildings comply with all construction regulations regarding fire, heat, and sound insulation.

Cadolto's cleanrooms are produced with a maximum degree of prefabrication in the factory halls. For example, furniture installation and medical technology are carried out in the factory. After leaving the factory halls, the modules are transported by trucks to the construction site and then placed on the foundation. Thanks to the high degree of prefabrication inherent in modular construction, valuable time can be saved during the construction process. Significant reductions in emissions and on-site construction traffic are also achievable. This approach is not only highly sustainable but also allows for the maintenance of surrounding operations.

Equipment with Highest Quality in an Intelligent Building Structure

Both the furnishings and the layout design of the cleanroom must meet the requirements for efficient use of available space.

High-Quality Equipment

Furniture and fixtures for cleanroom workstations must meet specific hygiene and safety requirements depending on the production environment, which vary according to application purposes and cleanliness classes.
In modular cleanrooms, all surfaces are smooth, non-porous, abrasion-resistant, and rounded at the corners. Wall and ceiling materials also meet all requirements. Floors are installed according to cleanroom standards and, depending on the requirement, may include a skirting. Materials such as rubber, synthetic, or PVC with a cleanroom coating, up to pharmaceutical terrazzo flooring, are used for the floors.

The door systems are installed according to hygiene standards. The airlock function includes an electric lock for airlock doors with up to five doors as a functional unit. Doors can also be equipped with an indicator showing room availability (free/occupied). An emergency button for quick opening or closing of the doors is also installed. All furniture units in the cleanrooms are designed for maximum robustness.

Different activities in cleanrooms require different temperature conditions. Depending on the requirements, a GMP-compliant cleanroom air conditioning system can be installed without issue. The air conditioning unit is installed in a technical module on the roof of the building. The heating system is designed so that it can be easily connected to the building's existing heating system.

For air treatment of the cleanrooms, an air handling unit (AHU) with an appropriate air conditioning system is used. The system complies with the hygiene guidelines DIN 1946 T 4. Depending on the disinfectant used, the system can optionally be fully lined with stainless steel. It operates with 100% outside air. The supply air undergoes two-stage filtration within the unit (F7, F9). H14 filters are installed at the end of the filter outlet in the rooms. The differential pressure of the final filters is monitored room-by-room. Filter load can be displayed on the central control system or, if limits are exceeded, forwarded as an alarm message.

The outside air is heated, humidified, or cooled according to requirements. Pass-through units or safety cabinets can be integrated into the AHU system.

Electronic volume flow controllers are used to implement pressure stages. The pressure regulation is decentralized via controllers and calibrated pressure sensors. The basis for pressure regulation is the pressure reference line, installed as a ring line within the building. The electronic output signals of the controllers are recorded in the building automation system (BAS) and can be centrally evaluated and monitored.

User-Oriented Room Design with Maximum Safety

During work in a cleanroom, an employee traverses various routes through different room classes. These routes should be minimized through intelligent planning: airflow and filter systems ensure particle removal. The goal is to arrange the rooms and their cleanliness levels in a sequence from low to high, matching the workflow steps. Rooms with the highest cleanliness level and thus the highest pressure are built at the end of the route. Access for employees to the cleanrooms is via an airlock system designed to generate as high a particle-free environment as possible. Especially regarding products, their safety is of utmost priority. If cleanroom products pose a hazard, maximum safety for personnel is naturally guaranteed.

Modular Solution Meeting the Highest Standards at University Hospital Düsseldorf

Cadolto completed the Liver and Infection Center (LIZ) at the University Hospital Düsseldorf within 16 months. The two-story building covers a gross floor area of 4,930 m². The 68 modules were manufactured with a maximum degree of prefabrication in the factory halls and transported by trucks to the construction site. The building was constructed according to the structural and hygienic standards for infectious disease and hepatology research, including special isolation units and high-security laboratories according to BSL (biosafety level) 4.

The modular construction meets all hygienic and structural requirements for treating highly infectious patients, including those with Ebola or Lassa fever. The center includes gastroenterology, hepatology, and infectious diseases with four outpatient clinics: infection outpatient clinic, tropical medicine outpatient clinic, hepatitis outpatient clinic, and liver center. The ground floor houses a high-security infection unit with special isolation rooms. High-security laboratories (BSL3) for diagnostics and research are also part of the building. Outpatient clinics, functional and doctor’s rooms, laboratories, waiting areas, and the research and teaching departments are located on the upper floors.