1. Cleanroom layout
A cleanroom generally consists of three main areas: clean area, semi-clean area, and auxiliary area. Cleanroom layouts can be arranged in the following ways:
(1). Surrounding corridor: The corridor can be windowed or windowless and serves as a viewing area and equipment storage space. Some corridors may also have internal heating. Exterior windows must be double-glazed.
(2). Inner corridor: Cleanroom is located on the perimeter, while the corridor is located within. This type of corridor generally has a higher cleanliness level, even on par with the cleanroom.
(3). End-to-End corridor: Cleanroom is located on one side, with semi-clean and auxiliary rooms on the other.
(4). Core corridor: To save space and shorten piping, cleanroom can be the core, surrounded by various auxiliary rooms and concealed piping. This approach protects cleanroom from the effects of outdoor climate, reduces cooling and heating energy consumption, and contributes to energy conservation.
2. Personal decontamination routes
To minimize contamination from human activity during operations, personnel must change into cleanroom clothing and then shower, bathe, and disinfect before entering cleanroom. These measures are referred to as "personnel decontamination," or "personal decontamination." Change room within cleanroom should be ventilated and maintain positive pressure relative to other rooms, such as the entrance. Toilets and showers should maintain a slightly positive pressure, while toilets and showers should maintain negative pressure.
3. Material decontamination routes
All objects must undergo decontamination before entering cleanroom, or "material decontamination." The material decontamination route should be separate from cleanroom route. If materials and personnel can only enter cleanroom from the same location, they must enter through separate entrances, and the materials must undergo preliminary decontamination. For applications with less streamlined production lines, an intermediate storage facility can be installed within the material route. For more streamlined production lines, a straight-through material route should be employed, sometimes requiring multiple decontamination and transfer facilities within the route. In terms of system design, the rough and fine purification stages of the cleanroom will blow off a lot of particles, so the relatively clean area should be kept at negative pressure or zero pressure. If the risk of contamination is high, the inlet direction should also be kept at negative pressure.
4. Pipeline organization
The pipelines in dust-free cleanroom are very complex, so these pipelines are all organized in a concealed manner. There are several specific concealed organization methods.
(1). Technical mezzanine
①. Top technical mezzanine. In this mezzanine, the cross-section of the supply and return air ducts is generally the largest, so it is the first object to be considered in the mezzanine. It is generally arranged at the top of the mezzanine, and the electrical pipelines are arranged below it. When the bottom plate of this mezzanine can bear a certain weight, filters and exhaust equipment can be installed on it.
②. Room technical mezzanine. Compared with only the top mezzanine, this method can reduce the wiring and height of the mezzanine and save the technical passage required for the return air duct to return to the upper mezzanine. The return air fan power equipment distribution can also be set in the lower passage. The upper passage of a dust-free cleanroom on a certain floor can also serve as the lower passage of the upper floor.
(2). Horizontal pipelines within the upper and lower mezzanines of technical aisles (walls) are generally converted to vertical pipelines. The concealed space where these vertical pipelines reside is called a technical aisle. Technical aisles can also house auxiliary equipment not suitable for cleanroom, and can even serve as general return air ducts or static pressure boxes. Some can even accommodate light-tube radiators. Since these types of technical aisles (walls) often utilize lightweight partitions, they can be easily adjusted when processes are adjusted.
(3). Technical shafts: While technical aisles (walls) typically do not cross floors, when they do, they are used as a technical shaft. They are often a permanent part of the building structure. Because technical shafts connect various floors, for fire protection, after internal piping is installed, the inter-floor enclosure must be sealed with materials with a fire resistance rating no lower than that of the floor slab. Maintenance work should be carried out in layers, and inspection doors must be equipped with fire-resistant doors. Whether a technical mezzanine, technical aisle, or technical shaft directly serves as an air duct, its interior surface must be treated in accordance with the requirements for cleanroom interior surfaces.
(5). Location of the machine room. It is best to place the air-conditioning machine room close to the dust-free cleanroom that requires a large air supply volume, and strive to keep the air duct line as short as possible. However, in order to prevent noise and vibration, the dust-free cleanroom and the machine room must be separated. Both aspects should be considered. Separation methods include:
1. Structural separation method: (1) Settlement joint separation method. The settlement joint passes between the dust-free workshop and the machine room to act as a partition. (2) Partition wall separation method. If the machine room is close to the dust-free workshop, instead of sharing a wall, each has its own partition wall, and a certain width of gap is left between the two partition walls. (3) Auxiliary room separation method. An auxiliary room is set up between the dust-free workshop and the machine room to act as a buffer.
2. Dispersion method: (1) Dispersion method on the roof or ceiling: The machine room is often placed on the top roof to keep it away from the dust-free workshop below, but the lower floor of the roof is preferably set as an auxiliary or management room floor, or as a technical mezzanine. (2) Underground distributed type: The machine room is located in the basement. (3). Independent building method: A separate machine room is built outside the clean room building, but it is best to be very close to the clean room. The machine room should pay attention to vibration isolation and sound insulation. The floor should be waterproofed and have drainage measures. Vibration isolation: The brackets and bases of the vibration source fans, motors, water pumps, etc. should be treated with anti-vibration treatment. If necessary, the equipment should be installed on a concrete slab, and then the slab should be supported by anti-vibration materials. The weight of the slab should be 2 to 3 times the total weight of the equipment. Sound insulation: In addition to installing a silencer on the system, large machine rooms can consider attaching materials with certain sound absorption properties to the walls. Soundproof doors should be installed. Do not open doors on the partition wall with the clean area.
5. Safe evacuation
Since the clean room is a highly enclosed building, its safe evacuation becomes a very important and prominent issue, which is also closely related to the installation of the purification air conditioning system. Generally, the following points should be noted:
(1). Each fireproof or cleanroom area on a production floor must have at least two emergency exits. Only one emergency exit is permitted if the area is less than 50 square meters and the number of employees is less than five.
(2). Entrances to cleanroom should not be used as evacuation exits. Because cleanroom routes are often circuitous, it can be difficult for personnel to quickly reach the outside if smoke or fire engulfs the area.
(3). Air shower rooms should not be used as general access routes. These doors often have two interlocking or automatic doors, and a malfunction can significantly impact evacuation. Therefore, bypass doors are typically installed in shower rooms, and are essential if there are more than five employees. Normally, personnel should exit cleanroom through the bypass door, not air shower room.
(4). To maintain the indoor pressure, the doors of each cleanroom within the cleanroom should face the room with the highest pressure. This relies on pressure to hold the door closed, which clearly contradicts the requirements for safe evacuation. In order to take into account the requirements of both normal cleanliness and emergency evacuation, it is stipulated that doors between clean areas and non-clean areas, and doors between clean areas and the outdoors shall be treated as safety evacuation doors, and their opening direction shall all be in the direction of evacuation. Of course, the same applies to single safety doors.
Post time: Sep-09-2025