Clean Rooms are workplaces where contamination is controlled. They provide an environment for research, development and manufacturing of equipment or processes which are susceptible to airborne contaminants like dust particles, bacteria etc and are generally moisture- sensitive.

The Clean Room applications range from the fabrication of microscopically small sub-assemblies, electronic devices and instruments, to the increasing demand for more sterility and purity in drugs, foods and a germ free atmosphere for medical and biological applications.

Contaminants can be particulate or chemical. Particulate contaminants may be inert (dust) or alive (Bacteria, spores, fungi). The live particulate contaminates are capable of multiplying. Contaminates can come from a wide variety of sources; air (the cleanliness of which is defined according to the classes of clean rooms and classes of dust); water, chemicals, the physical plant itself, and personnel.

Thus the clean room are becoming specially constructed enclosed areas, environmentally controlled with respect to airborne particles, temperature, humidity, air pressure, air pressure flow patterns, air motion, vibration, noise and viable organisms.

APPLICATIONS OF CLEAN ROOMS
Major application areas of clean rooms are in the Electronic industry, pharmaceuticals, aerospace, automotive, computers and many others requiring more stringent manufacturing conditions.

Few exclusive clean room examples where Bry-Air dehumidifiers are effectively employed are:

Semiconductor Clean Rooms: -
Microcircuits, microchips manufacturing requires, hygroscopic polymers called photo resists to mask circuit lines for etching processes. Because of their hygroscopic nature, they absorb moisture and therefore microscopic circuit lines are cut or bridged, resulting in circuit failures.

In addition, in semiconductor manufacturing, when the humidity level fluctuates in a wafer fabrication area, a multitude of problems can occur. Bake-out times typically increase, and the entire process generally becomes harder to control. Humidity levels above 35% RH make the components vulnerable to corrosion. Additionally, as developer solvents are sprayed onto the wafer, the solvents evaporate rapidly, cooling the wafer enough to condense moisture from the air. This extra water can change the developer characteristics and be adsorbed onto the semi-conductor layers. This can cause swelling and further product quality problems, necessitating additional process control.

Pharmaceutical Clean Rooms: -
In Pharmaceutical manufacturing facilities, high humidity causes fine powders to adsorb moisture, clogging the powder feed to the tableting press. Powder inconsistency caused by moisture adsorption results in crumbling tablets and clogged tablet dies. Variations in humidity mean difficult adjustments in bed temperature and spraying rates, resulting in heat damage and moisture intrusion. Also, humidity in air ductwork creates moist places for bacterial colonies to grow and causes process contamination.

Humidity control is an important variable to-

• Prevent corrosion
• Prevent condensation on work surfaces
• Reduce static electricity
• Prevent product contamination
• Provide personal comfort
• Compensate for hygroscopic materials and
• Control microbial growth within the clean rooms.

BRY-AIR SOLUTION
Normal air-conditioning, alone, is unable to provide the required conditions in clean room. Desiccant Dehumidifiers in combination with air-conditioning provide the required humidity and temperature parameters necessary for the Clean Room.

In a desiccant system, the process airstream passes through a desiccant medium. The desiccant adsorbs moisture directly from the airstream, and the resulting dehumidified air is routed to the clean room.

Bry-Air Desiccant dehumidifiers can maintain dew points to very low levels consistently, such as -600C a manifold reduction in the air moisture beyond what can be achieved by a standard HVAC grade refrigeration systems.