Cleanroom Elements and Climate Control
There are two types of airflow systems that can be used in cleanroom climate control. Primary cleanroom air is recirculated through the room by ceiling mounted HEPA or ULPA filters. The primary air can be through fan filter modules or ducted primary recirculation fans directly connected to ceiling mount HEPA terminal units. The air is usually returned back through either low side wall returns or raised access flooring. The air pushes through the room from the ceiling. The lower the number of particles allowed in the cleanroom, the higher the number of HEPA or ULPA filters required, thusly the higher the airflow or air changes in the clean room.
Laminar flow in clean rooms is optimal with a raised access floor which allows the air to flow through the room on straight lines. Accentuated by the laminar flow of air into the cleanroom the air in the room is continually flowing through the room. Multiple industries use cleanrooms: hospitals use them because they require spaces that are protected against contamination, thus enabling practitioners to work with medicine and viruses in a safe space; sectors that test industrial equipment, drug testing and scientific research are also amongst those in need of cleanrooms. The use of cleanrooms is necessary because the risk of dust and other particles in the environment can interfere with, destroy, or otherwise compromise samples and or products significantly.
Cleanrooms are assembled in factories with components such as non particle shedding materials. These components are typically used in cleanrooms to enhance cleanroom climate control. Cleanrooms normally have temperature and humidity control in the cleanroom space, so materials that can form a vapor barrier are typically used. Epoxy paints, foil backed drywall, will typically the perimeter of the cleanroom zone. When drywall is used, the drywall is covered with aluminum lining material to keep from the drywall being damaged.
In addition, cleanrooms can be designed in various sizes, from small to medium range to much greater, but may also be mobile or fixed, depending on the needs of those using the clean room and what materials they’ll be working with. The products being constructed inside the clean room area often dictate the size, and materials used to construct the clean room envelope.
Whatever direction the users agree on for a design, it is very important for these spaces to be cleaned and closed rooms, with functioning cleanroom climate control, which can then be used to maintain, preserve and control the amount of a wide range of pollutants. Examples of materials that might be found in a cleanroom are computer hard drives, or hazardous chemicals that must not be exposed to the outside world, not only for the integrity of the sample, but also for the safety of public health.
Clean space entrances that are ready for use are a milestone in the design process and the actual construction of a purified enclosure. Because pollution must be eliminated first, thus avoiding compromising the integrity of the treated area, small rooms are in direct contact with the cleanroom, and the products are brought in through this mode. The rooms help form a barrier for the cleanroom to outside ambient. The barrier rooms often are areas where materials entering the cleanroom are wiped and cleaned of particles before entering the cleanroom area. The additional rooms also help support the cleanroom climate control. There is often another additional room with which people must be sprayed, cleaned, and then suited up in specially designed suits meant both to protect the wearer from whatever hazardous chemicals they may be handling in the cleanroom, but also to protect the cleanroom from any pollutants brought in by the people themselves. Pollutants can be carried in by people through their hair, shoes or clothing. Humans shed dead skin on a continual basis and these particles are controlled by personnel wearing cleanroom suits, gloves, hairnets, shoe booties and maintaining hygiene by washing up before suiting up.
There are many rules in place for the installation of cleanroom systems, and cleanroom installers must comply with these cleanroom protocols when they are constructing a cleanroom area. Planning and construction of just the cleanroom climate control is a process that requires much effort as there are building codes and energy recovery standards which must be observed. By controlling temperature and humidity in clean areas, the facilities are terribly inefficient in energy management. With building officials focusing on energy management these days, new requirements are being put in place for controlling the energy in the cleanroom areas.
The only thing that will trump energy management is personnel protection inside the cleanroom areas. When certain chemicals or hazards are presented in the cleanroom area, there are typically high levels of exhaust air. The exhaust temperature can be reclaimed through energy recovery means as long the chemicals or toxins do not damage the energy recovery materials. As building codes advance, designers and owners will have to have a higher knowledge base to designing cleanroom facilities.
Digital Air Control’s staff has been designing and building cleanroom facilities for over 20 years. Many changes have come to cleanrooms since the early 1990’s and cleanrooms will continue to change. Contact Digital Air Control’s staff to assist with your cleanroom needs.