Clean rooms for the production and use of semiconductor materials include valuable technical equipment and have high-performance air ventilation systems for the exchange of filtered fresh-air. This results in a laminar flow with high air exchange rates. Further these rooms contain high fire loads e.g. cable material, plastics etc., which generate high temperatures and dense smoke in case of fire.
FOGTEC systems are ideal for the protection of these and other associated fire risks. This is due to the effective extinguishing properties in combination with very low flow rates, and the smoke scrubbing effect resulting in a reduction of consequential fire damage caused by large amounts of partly corrosive combustion products that settle on equipment in the vicinity of a fire.
Additionally water mist acts like a temperature shield, reducing the heat radiation and consequently the thermal stress on equipment close to the fire source. This at the same time enables people to safely find escape ways and for trained personnel to rescue people in the fire area or to manually attack a fire.
Since gas extinguishing systems - like CO2, chemical and inert gases - are only effective if the necessary gas concentration in the protected room is achieved, the use of such systems in clean rooms is virtually impossible due to the ventilation openings in the ceiling and floor. Because FOGTEC systems for clean rooms provide a constant flow of water mist, the necessary volume of extinguishing medium is achieved during the complete running time of the FOGTEC system. Concerns regarding ventilation or leakage from the area are not major concerns when using the system.
Inert gases work by reducing the oxygen concentration in the room to levels that may become dangerous to people in the area, therefore pre-warning times must be ensured, during which the fire is allowed to spread further. It is not essential to have a pre-warning time with the FOGTEC system. The use of conventional sprinklers in most cases is inappropriate for clean rooms because of the expected water damage in case of false activation and alarm and the weight restrictions of the filter ceilings used in clean rooms.
Pipe work required for FOGTEC systems is so small and light that an installation is easily achieved even as a retrofit and the expected water damage should be of little concern. Due to the high operating pressure, high-pressure water mist offers a wide spray with high momentum, using the optimal droplet distribution for fire fighting and at the same time compensating for the influence of the high-performance ventilation systems.
