Both excess and insufficient Humidity in the computer room can threaten system reliability. Too much moisture in the air can accelerate oxidation of electronic circuits, conductors and connectors, and can provide high-resistance current paths that make circuits perform unpredictably. A lack of moisture in the air increases the potential for equipment 'zapping' from static-electricity. Smoke and Fire present obvious hazards to the Computer installation. Smoke particles deposited on disk and tape surfaces can render the recorded data unrecoverable.
Excessive heat can also damage recording media, and cause immediate failure of computer electronics.
In addition to causing permanent damage to equipment, the interruption of operations during a disk or tape write cycle can destroy the contents of open files. It has also been reported that both Water and Halon fire retardants have a greater possibility of damaging electronic devices if they are discharged while power is applied to those circuits. Many cases of erratic computer performance, as well as catastrophic failure, have been attributed to poor Power quality. Electricity provided by Public Utilities is often plagued by over and under voltage conditions, as well as unpredictable spikes, drops, and contamination from high-frequency noise. While these conditions are not often obvious and do not affect most household appliances, they can spell disaster for computer facilities.