Eight strong reasons to clean your data center

 Although there are many reasons to maintain a clean environment, there are eight main strong reasons that should prompt managers to clean their sub floor plenums regularly.

1.  Electrostatic Discharge and Dust Fires

Evidence has linked the constant movement of air and dust across concrete surfaces, combined with humidity fluctuations, as the cause of severe electrostatic discharge.  Dust fires, that leave only a burn mark to show that they have occurred, are found in unclean subfloor plenums.  These electrostatic discharges can adversely affect memory chips.  A voltage discharge can also directly damage the circuitry of a system, especially in terminals and microcomputers.  These units can tolerate up to a 1,000-volt discharge without being affected, yet normally a person can feel a shock only if it is greater than 3,000 volts.

 2.  Ferrous Metals on Circuit Boards

Because of the high volume of air blown over circuit boards, to cool them, both dust and tiny ferrous metal slivers are deposited on electronic components because of their magnetic properties.  Because components are becoming smaller and are being packed more densely on a circuit board, the likelihood of problems is increased.  Additionally, any particle that can absorb moisture can also conduct electricity, such as, Carbonaceous particulate.  These carbon residues are moisture-absorbent particulate from automobile exhaust (brought in by air conditioning), smoke, and oxidized organic material such as clothing fibers, paper dust, and hair.

Interestingly, carbon dust is also combustible.  It has become the mythical bug of computer lore, which shorted out one of the first computers by straddling two poles of a switch.  Like the bug, which mysteriously vanished after the incident, carbon contaminant-related failures of computer circuit boards are often logged "cause unknown."  This, because carbon particulate incinerates at the moment that it causes damage, thereby resisting identification by service technicians, who are more inclined to attribute board failures to faulty components than to microscopic contaminants.

3.  Overhumidity and Rust

On the other end of the spectrum from electrostatic discharge problems, are over-humidity and rust.  Rust can be found on the floor jacks and grid, as well as in air conditioning and computer equipment.  Humidity, at its worst,
causes condensation on equipment resulting in, not only rust, but also short circuits.  Infrared humidification systems, that provide instant on/off service, use electric coil systems that bring a column of water to the boiling point to create water vapor.  These preheat units allow the dust and lint in the subfloor air plenum to gather on the coils of HVAC preheat units which then smoke when operated.  Carbon and smoke can set off fire detectors and/or affect disk drives.

 4.  Head Crashes and Mechanical Wear

Today's disk drives are particularly vulnerable to dust, because the distance between the head and the thin film disk is now on average much less the thickness of a human hair or even a dust particle.  Read/write errors and head crashes result and tape drives can also be affected when tiny dust particles, capable of passing through equipment filters, agglomerate inside disk drives and create particle sizes capable of striking the floating head.  This emphasizes the need for vacuums that can remove particulate to the submicron level.  Airborne dust also reduces lubrication in mechanical linkages, which in turn, accelerates parts wear.

5.  Halon Dumps

Dust and other small particulate can look like smoke to subfloor fire detectors.  The electronic eye cannot distinguish between smoke particles and dust.  Should the static pressure in the subfloor be released, such as when a tile is pulled, dust laden air can cross over several detectors on its way to the open tile setting off the necessary number of detectors for a dump.  According to the Halon Research Center, one third of the Halon dumps occur erroneously, that's over 1,000 metric tons a year.  Since Halon 1301 & 1211 have been linked with the depletion of the stratospheric ozone layer that protects the earth from damaging ultraviolet radiation and as a result DuPont has limited its production, it is both cost effective and prudent to prevent such erroneous dumps.

6.  Employee Health

Process computer cooling is different from comfort cooling found in office spaces.  This means that building codes requiring fresh air for people is often ignored.  With few people and lots of equipment, probably 95% of computer rooms don't follow the fresh air requirement.

Indoor air quality and sick building syndrome are directly connected to the removal of particulate contamination.  Specialized filtration keeps such problems in check.  HEPA filtered computer room vacuums that filtrate down to 0.3 microns and 99.97% efficiency totally eliminate bacteria, fungus and other disease causing particulate.  This periodic filtration (annually or semi-annually) to the aforementioned levels will prevent health risks due to indoor air pollution.  (Note particulate size criterion based on Chart I).  Thus computer rooms are good candidates for Indoor air pollution.  We have had many cases where employees were chronically sick and missing work inexplicably and after a thorough cleaning of the ceiling interstitial and sub floor plenum the employees themselves reported a sharp decline in symptoms of sickness.  

CHART I:  Typical pollutant sizes