Alum-A-Frame Enclosures

Clean rooms can be very large. Entire manufacturing facilities can be contained within a clean room with factory floors covering thousands of square meters. They are used extensively in semiconductor manufacturing, biotechnology, the life sciences and other fields that are very sensitive to environmental contamination.The air entering a clean room from outside is filtered to exclude dust, and the air inside is constantly re-circulated through high efficiency particulate air (HEPA) and ultra low penetration air (ULPA) filters to remove internally generated contaminants.Staff enter and leave through airlocks (sometimes including an air shower stage), and wear protective clothing such as hats, face masks, gloves, boots and cover-alls. Equipment inside the clean room is designed to generate minimal air contamination. There are even specialized mops and buckets. Clean room furniture is also designed to produce a low amount of particles and to be easy to clean. Common materials such as paper, pencils, and fabrics made from natural fibers are often excluded; however, alternatives are available. Low-level clean rooms are often not sterile (i.e., free of uncontrolled microbes) and more attention is given to airborne particles. Particle levels are usually tested using a particle counter. Some clean rooms are kept at a higher air pressure so that if there are any leaks, air leaks out of the chamber instead of unfiltered air coming in. Clean room HVAC systems often control the humidity to low levels, such that extra precautions are necessary to prevent electrostatic discharges. Low-level clean rooms may only require special shoes, ones with completely smooth soles that do not track in dust or dirt. Entering a cleanroom usually requires wearing a cleanroom suit. In cheaper cleanrooms, in which the standards of air contamination are less rigorous, the entrance to the cleanroom may not have an air shower. There is an enteroom, in which the special suits must be put on, but then a person can walk in directly to the room (as seen in the photograph on the below).