B-4 Dell PowerVault 530F SAN Appliance User’s Guide/ High-humidity conditions can cause moisture migration and penetration into the sys-tem. This moisture can cause corrosion of internal components and degradation ofproperties such as electrical resistance, thermal conductivity, physical strength, andsize. Extreme moisture buildup inside the system can result in electrical shorts, whichcan cause serious damage to the system.Each Dell system is rated to operate at 8 to 80 percent relative humidity, with ahumidity gradation of 10 percent per hour. In storage, a Dell system can withstandfrom 5 to 95 percent relative humidity.Buildings in which climate is controlled by air-conditioning in the warmer months andby heat during the colder months usually maintain an acceptable level of humidity forsystem equipment. However, if a system is located in an unusually humid location, adehumidifier can be used to maintain the humidity within an acceptable range. Operating a system at high altitude (low pressure) reduces the efficiency of forcedand convection cooling and can result in electrical problems related to arcing andcorona effects. This condition can also cause sealed components with internal pres-sure, such as electrolytic capacitors, to fail or perform at reduced efficiency.Each Dell system is rated to operate at altitudes from –16 to 3048 meters (m) (–50 to10,000 feet [ft]) and can be stored at altitudes of –16 to 10,600 m (–50 to 35,000 ft).& A clean operating environment can greatly reduce the negative effects of dust andother particles, which act as insulators and interfere with the operation of a system'smechanical components. Also, in addition to regular cleaning, you should follow theseguidelines to deter contamination of the system equipment: Do not permit smoking anywhere near the system. Do not permit food or drink near the system. Use dust covers when the system is not in use. Keep all diskettes in a closed diskette box when not in use. Close windows and outside doors to keep out airborne particles.