Contemporary prefabricated buildings’ construction technologies allow creating quality clean premises within minimal time and cost.
Clean rooms are those where a specified concentration of suspended particles (volatile solids, dust, microorganisms, and chemical vapor) is maintained per air volume unit. In accordance with ISO 14644, depending on use, clean rooms are divided into 9 classes (1 to 9). The requirements to clean rooms in pharmaceutical and microbiological production are described in the Good Management Practices (GMP), where rooms are divided into 4 classes (A to D). Apart from the air pollution level, the clean rooms technology also means temperature, moisture, and pressure control.
Being part of food and pharmaceutical enterprises, clean rooms are used in medical institutions, as well as for conducting scientific research. As a rule, they are erected according to “house in a house” principle.
When creating sterile rooms, the number of locations (corners, recesses etc.) where dust can be accumulated or microorganisms can develop, is minimized as much as possible during the design. For convenience of sanitary treatment of rooms, floor-to-wall and wall-to-wall junctions has to be arranged using a special rounding (rounded molded element). The same roundings may be used on partitions-to-furniture junctions, as well as those between partitions and equipment installed against the wall.
In clean rooms, cables can be laid the following ways:
The main principle for ensuring cleanliness is creation of excessive pressure in the premise, compared with the neighboring rooms. The supply air has to exceed the exhaust air by at least 20%, and if the premise has got windows – by at least 30%. Initially filtered air is supplied via the ceiling panels and exhausted through the lower part of the walls. With such air flow direction, particles contained in the air, are brought down to the floor and no droughts are allowed, which could raise dust from the floor.
Materials’ selection for walls and ceilings is one of the most important stages of design and construction of clean rooms, because it affects not only a premise’s ability to maintain cleanliness, but also the ease and long life of structures’ operation.
Clean rooms are subject to the following key requirements:
Sandwich panels with polyisocyanurate foam (PIR) core and steel facing coated with FoodSafe special film laminate, which is characterized with high durability against organic substances, is easily cleaned and does not absorb water, fit these criteria the best. Decopan FRP cleanroom panels can also be used.
PIR core sandwich panels are lightweight and thus can be carried and assembled manually, which is a substantial advantage for erection of clean rooms in an already constructed building. Such panels are non-hygroscopic and prevent spreading of fungi and mold, and thus can be easily applied in projects of eco-friendly productions. Application of Ruukki Energy sandwich panels with sealant ensures complete air-tightness (up to n50 = 0 l/v2h) and increases the efficiency of ventilation operation.
To increase air-tightness of clean rooms made of sandwich panels, special units are applied, ensuring reliability of junctions and ease of assembly.
Clean rooms’ flooring is subject to special requirements:
The floor top surface may be made of polymer materials (tile, self-leveling , or rolled) or aluminium.
Openings in clean rooms have to ensure sufficient air-tightness to avoid pressure leakages or penetration of microparticles from the outside. For this purpose, junctions between separate elements are additionally sealed with sealants. Doors and windows coatings have to ensure rigid surface, be resistant to treatment with disinfection solutions, as well as not to facilitate emergence of microfissures and separation of microparticles.
Manual/automatic swing, double-action swing, or sliding doors can be used in clean rooms. The door leaf facing may be produced of antibacterially-coated galvanized metal, stainless steel, or aluminium. PIR is most frequently used as door core.
Observation or pass-through windows may be used in clean rooms. Extra rigid aluminium profile with high-quality protective coating is normally used for window production. The profile material has to be resistant to faintly acid and alkaline environments, impact of UV irradiation and temperature drops (to withstand fluctuations from -55°C to +70°C without losing operational properties).